Help!
I apologize in advance for the long post- but i need help!

I've been working on this for quiet a while and am running out of options.

Some time ago my245 started getting harder and harder to start. fuel economy plummeted and it was suffering performance issues. Poor idle at stop lights and poor throttle response. But every now and again she would drive fine (accept for the hard starts- they continuously got worse.
With the Hard starts also came small little sputters. those sputters eventually became small backfires in the intake manifold and the hard starts became no starts.

Things I have done:
Replaced Fuel Filter
New Injector Seals
Jumped the Fuel pump relay.
- I can hear both pumps run, and same problem persists when attempting to start car while jumper in place

Checked the Cold start injector and thermo time switch
- both seem to operate in spec.

Cleaned the Flame trap
replaced timing belt.
cleaned the auxiliary air Valve.

I can get her to "run" at an idle if i spray wd-40 into one of the intake ports. the interesting part there is usually when you spray wd or starting fluid into an intake manifold, the RPM's will increase- mine will barely run.

Again, after cranking over and over, she'll fire off, but nearly immediately backfire out the intake manifold blowing the hose to the auxiliary airline off either the intake manifold or the Auxiliary air valve- some times both.

The Volvo really wants to run. and I really miss driving her. Please Help me diagnose this.

after doing some general diagnostics-

checking continuity of the Ballast resistor and Coil along with the impulse sender- and generally unplugging and replugging things a bunch of times (there by cleaning some corrosion)

the car started... HOWEVER, I did have to crank a bunch of times and I had to feather the Accelerator pedal (which primarily controls air flow and fuel right?)

now that the car started, it still wont stay started, or running rather.

Even if it does run for a hopeful length of time, it Bucks hard almost like it is shutting off or loosing all spark for a moment and stalls then quits running.(hopeful = hopefully it will stay running, but then breaks my heard as it inevitably dies)(backfires are rare now also.

furthermore, if i feather up the accelerator and Bring the RPM's up, it tuns pretty smooth.

SO- where can I go from here?

"
furthermore, if i feather up the accelerator and Bring the RPM's up, it runs pretty smooth.""


Since your efforts with the ignition system have improved it so it starts and no longer backfires, and you mention cleaning off some corrosion, you might want to continue with ignition timing.

feathering...RAISING THE RPMs and it runs smoothly....Raising the RPM effects the timing...thru the mechanical advance in the distrubutor as well as the vaccuum advance.

The other thing related to the KJet is that it is running too lean at idle.
Since you have a Lambda system you can confirm this by checking the CO level...using a Digital Meter at the O2 sensor OR using a DWELL METER at the CO Test Point --- which the wire located in just in front of the drivers side shock tower.

go to this website

http://www.volvowiringdiagrams.com/?dir=volvo/Trouble%20Shooting%20Guides

and download the Volvo Problem Solver Advanced Edition.

It covers KJet and the Bosch Breakerless Ignition problems quite well.

CB-

"Since you have a Lambda system you can confirm this by checking the CO level...using a Digital Meter at the O2 sensor OR using a DWELL METER at the CO Test Point..."

I was with my Mechanic when he tested the O2 and said it was within spec- right were it was supposed to be, so I don't think I'm running Lean.
--
1979 245 DL

Thanks CB-

I'll take a look at the wiring- wiring and fuel injection are a little out of my league, but I'm learning a lot.

Today/ this weekend I plan on cleaning and re-gaping the plugs, checking the spark plug wires resistance, and opening the air flow sensor plate to see if there is anything blocking or obstructing it.

I hesitate on adjusting timing or messing with the fuel mix/ idle/ timing etc because I don't want to get something too out of whack to where I cant "reset" it

Justin.

I finally had a mechanic look at it and give me a direction.

Fuel pressure is at 90 PSI according to the mechanic.

Backfire was caused by a crack in the rotor cap. which the mechanic replaced.

the car still sufferers from an extreme hard start.

I'm going to replace the fuel pump check valve and some of the damaged vacuum hoses and see where that gets me.

any other suggestions would be helpful

thanks
--
1979 245 DL

"Fuel pressure is at 90 PSI according to the mechanic."

Is 90 psi normal for k-jet? That would be close to triple needed for LH2.4

You may be flooding the engine with too much gas, if pressures are too high.
--
1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.

Pressure for the K-jet system has to be measured through the Control Pressure Regulator--or, aka--the Warm-up regulator. 90 psi wouldn't be unheard of as line pressure. LH systems also have line pressure way above running pressure. The mechanic in question needs to read up on measuring running pressure for the K-jet. -- Dave

Dave,

how would you measure line pressure?

also, do you or anyone know a good test to see if the internal check valve on the main pump is any good?

I cant isolate this issue at all. it runs and drives fine, but there has got to be a solution to these hard starts.

thanks
J
--
1979 245 DL

J--I see Trev29 has posted a link to a fuel pressure gauge set up. It's difficult to imagine how it gets set up from a picture of individual parts. I wasn't more explicit in my post with the suggestion that your tech read up on K-jet fuel pressure checking because it's been at least 20 years since I've actually done it. I looked for a photo of how a rig should look all hooked up - found one in a Haynes manual - but not so easy to decipher. What you need is a set up that connects between the fuel distributor (using a variety of banjo bolts and fittings and "T") and the Control Pressure Regulator (CPR) and it must have a shut off valve in between to eliminate the return line at the CPR (the one I used at the shop had the valve built into the "T"). To measure line pressure you would close the valve and then energize the pump with the motor off. That's where you will see pressure in the neighborhood of 65-90 lbs. With the valve open so the return line is incorporated you'll see cold pressure of 20-35 lb range (depending on model # CPR). As the motor and CPR warm, pressure should rise to something in the 50-60 lb range (also depending on model CPR). If you can't find charts I can scan what I have and e-mail to you. -- Dave

"it runs and drives fine, but there has got to be a solution to these hard starts."

If line pressure drops to zero the moment the pump is turned off, then there would likely be hard starts if fuel pressure has to be built up from scratch on restart.

So there may be a leak (check valve?) that allows the system to depressurize.

"how would you measure line pressure?"

You'll have to rig together a gauge-hose setup with appropriate connectors.
eg. http://www.canadiantire.ca/en/pdp/automotive/auto-repair-tools/garage-tools/multi-testers/equus-fuel-pressure-tester-kit-0251020p.html

--
1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.

Trev29,

I have that fuel pump assembly- but don't have the correct adapters to go between the control pressure regulator and the fuel dist per the Green book CI test.

Because of that, I am trying to gather as much info as I can to try to diagnose if the Check valve is actually bad. Since I cannot replace the check valve itself due to having an aftermarket Pump, if it is bad, I'll need to replace the whole pump.

I am doing my best not to throw parts at it and hope it works. Both the fuel Pump and or a control pressure / warm-up regulator are very expensive.

are there any other tests I can do to isolate if the check valve is actually bad?
--
1979 245 DL

Dave and Trev,

the mechanic took a simple cold reading at the cold start injector to see if line pressure would be maintained after the car was turned off. it was 90psi and then it dropped straight to zero after the pumps were disengaged.

that being said, the mechanic suggested replacing the fuel pump check valve as that could be bad and cause the pressure drop.

He said that this was line system pressure, not control pressure. until the check valve is fixed and the system can hold pressure after the engine is off then readings on the fuel system would be misleading.

I hope that helps clarify the pressure issue- I must say that I am still a little confused.

But on the upside I ordered the Fuel pump check valve from IPD and should have it installed by Monday! we'll see what she does then...
--
1979 245 DL

HELP!

Check valve from IDP does not fit the after market Fuel Pump. I cant find any numbers on the fuel pump to even check the brand of the pump...

I was hoping to find out if the aftermarket Pump had an internal check valve... Because it not have a external one that bolts in to the outlet side. that is just a fitting to allow the banjo fitting to attach...

Does anyone know the part number for the external fuel pump? I'd like to get a price on a OEM one to replace the one thats in there.
--
1979 245 DL

In a recent post to H4L.9000 http://www.brickboard.com/RWD/index.htm?id=1587391&show_all=1

Machine Man wrote,
"The k- jet fires them all continuously . The reason for the CIS designation. They are overcome by pressure only and bad gas is pumped differently, for reasons of viscosity, of which there is no adjustment internally that can be had with a change in pluse width on the LH."

If as you wrote, "the mechanic took a simple cold reading at the cold start injector" and it was 90psi, would this be be same pressure as the other injectors were getting?
--
1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.

All I am about to say is from memory!
I might be a little fuzzy on it but if you read a good manual or k-jet source you will get a more correct definition/explanation of what is going on.

When first starting the engine a vacuum is created inside the intake manifold. All air needs to come up from that air flap but be controlled with out your foot!

The first amount of air that can and should only come through the auxiliary air valve (which used only during warmups). Plus, what either gets by the idle mixture screw (the black knob) and a very "partially open" throttle plate.

The throttle plate should only be held open "only by tiny little bit" (with later adjustments possible) by a stop screw but not enough to override the auxiliary air valve flow setting. I use about one quarter turn on that stop screw after it touches the lever that holds the plate open.
After you test the cold and warmed up idle speeds you tweak one or the other to set each and have warmed up idle for driving at 900 to 1000 rpm.

Looking down into AAV's top port, the vane inside should only be open about 1/8 inch or less of gap, at say, a 60 degree day.
There is a tiny nut that you just loosen and push around in its clearance hole. It holds one end of a spring that sets, tension/the gap, on the vane. An electric heater later moves that setting.

There is starting point or basic spec. call out using a shank of a twist drill bit that will get you close to a 12 to 1500 rpm cold idle speed you will desire.

The idea is to "time" the air flows using the open spaces of the two/three air settings to allow enough air to match up the mixture/control pressure set by the control pressure regulator and whatever the frequency valve does. These are not adjustable without gauges mentioned before.
You got to get your air flow going the right ways and in right amounts before pointing at fuel problems.

On the frequency valve, "You" should hear it buzzing anytime the engine is running as it vary fuel amount according to the O2 sensor and the ECU. The buzz should be heard after you crank and stop for a second or so!

If air/mixture it is set together, as a whole, to be "in-time" with the heaters warming up with the engine, the idle speed drops depending on the air temp affecting those heaters and of course the combustion in the cylinders.
Its the only adjustment you can make (cold) is with the that aux. air control valve.
A Warmed engine, its the throttle screw (last) and that black knob on k-jet. One will override the other, some. You have to experiment and listen. That stop screw is dangerous as it can quickly get you out of whack..or timing of the whole picture. That is you care to define what a whack is. I say, it follows cuss words for sure?

During cold starts there are two electric heaters mimic and control how the engine warms up. One is in that auxiliary air valve. It slowly closed the sliding vane shut to mimic the engine warming up.

The next heater does the same thing (as above) but it will adjust the fuel pressure that pushes against the air flap.
It will start out at a lower fuel pressure upon the flaps central piston to allow the flap rise more easily and provide extra fuel to the injectors for cold running conditions at startup.
The heater then increases the pressure to lean out the fuel volume through the injectors as the air through the Aux. Air Valve also decreases. Overall, the airflow stays the same through the flap and the control pressure regulator and frequency valve work with that amount.
The air flap of the fuel distributor is the mechanical equivalent to today's AMM. Some AMM's actually used vanes with electronic sensing of which are more "delicate" to environmental change when compared.

The gauge set, is the only way to tweak what controls the flap, pressure in the system and what returns back to the tank.

Frankly the injection system is going to work right unless there is gum from bad fuel or excessive wear from dirty air getting past the air filter.

Point there the least you can, as Bosch did a real good job on this fuel management system. That's an opinion from many others besides mine. 320K on mine, nothing replaced but pumps!

Air flow has to be the biggest item high on the list of this car.
Mainly because it's the first thing touchable by other mechanics or just most people. They know they are not musical or mechanical inclined but become fiddlers!

You guess it, using their fingers on screws instead of strings!

The sheet music is in the manuals and the our instruments are in tool boxes like other things treasured.

Hope this helps you get it to run without the foot in it!
Phil
PS, you may have to read it over and over to Phil in the "notes" I missed! (:-)

Intake backfires are caused by damaged/open valves (including from timing being off), or an extremely lean mixture.

The pumps may be running, but are the injectors clean and giving a fine mist pattern? Is the pump giving proper fuel pressure? Is the pressure regulator (if it has one, I'm pretty noob about Kjet) working?

Has the harmonic balancer slipped, thus throwing off your timing? Paint a line across it from the inside to the outside and see if the line moves. You can find info and I think photos on this in the FAQ.

Good luck!

Has the harmonic balancer slipped, thus throwing off your timing?


That won't happen with B21/B23. The pulley is not the same as on the B230.

But when I first read the original post I thought, "Stuck valve."

A compression test would tell whether or not this is the case.


--
'80 DL 2 door, '89 DL Wagon

A stuck valve would be interesting...

I'll try to see if I can borrow a compression tester this weekend- I'll follow up with results after I get them

One stuck valve would explain the backfire.

I'd suspect valve-deposits though. Those are more likely to happen and can seem not to have an effect on the car's running.


Cold means it needs a richer mixture, and if you have vacuum/intake leaks, you won't get a rich mixture like you need.

Ooh, I should have looked at the year. Good catch. I doubt anyone would replace a one-piece with a modern two-piece.

Even if it was a slipping HP it wouldn't directly affect the timing itself.

The notch in the outer edge is only part of a visual reference.




--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Not on its own, but the poster replaced the timing belt. If he used it for reference..... but anyway, it's moot because it's a solid HB.

I wonder if a seriously out of adjustment valve or a lot of valve deposits would do this. It seems like it would run on the other cylinders and poorly on the affected one though.

Does the big rubber "bulbous" connector ....between the Throttle Body/Intake and the K-Jet fuel unit have any cracks?

Are the two big hose clamps that hold it in place tight.

If there is a leak here it will hard start and then backfire with a force.

The timing being off is the other thing that will cause a backfire.

there is a plate on the drivers side under the hood by the shock tower that gives the timing degree and RPM specs.

CB.

the "bulbous" connector between the Throttle Body/Intake and the K-Jet fuel unit looks great. connectors are solid.

All the vacuum lines look good too- a little worn, but good.

if the KJet system is tight, you should confirm that the timing is correct. Get a timing light, put a dab of white paint on the timing marks on the crank pulley and confirm, getting the specs off that Emissions System Specs plate by the shock tower.

(FWIW reading Will's response, the B21, this engine you have does not have a Harmonic Balancer. It has a solid pulley.)

If you take off the Distributor Cap and look at the Star Wheel, is it firmly on the distributor shaft. It's held in place by a small pin that fits into a notch in the shaft and the star wheel. If the Star Wheel is lose on the shaft the timing will be off...the Star Wheel "tells" the coil when to fire.


How many miles are on this car/engine.

Have you ever checked the valve adjustment?

When you changed the timing belt, did you check the condition of the wiring that run under the crank pulley for insulation failure. The wires that run from the distributor to the ignition module, on the fender below the washerfluid bottle?

If you take off the Distributor Cap and look at the Star Wheel

Pull the plugs and clean and gap them, or replace with fresh ones. They may be black from the poor starts.

Also, the rough idle may be from a non-firing plug due to a bad cable. The car will run on three cylinders but will have poor idle and fuel economy.
--
1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.

Trev29,

Plugs are a little sooted and slightly carbon fouled indicating Incorrect mixture setting. I cleaned them up hoping it would help them fire off and start the engine. no such luck.

although, they are wet, getting fuel - but carbon fouled plugs usually indicates too much or rich burning. But without the car actually running, and my continuous cranking of the ignition, its more likely flooding due to the cold start injector rather than the incorrect air fuel mix...? does that even sound plausible?

Very interesting about WD40 that it will run on it. I am sure it must be the propellant that helped more and not the solvent, by itself, that WD40 truly is.

I presume this is a K-JET system. In this case, it runs on having the proper fuel pressure going to the right places.

Since it does run, somewhat, we can rule ignition woes for the most part.

Timing of the valves and the distributor would be my next highest priority.

Check for All of the marks to be smacking on their respective marks.

If you roll up on number one's TDC make sure the front two lobes are laid out like cats ears by looking through the oil filler cap hole.
Check to see if the distributor rotor button is pointing at number one wire. I think there is a notch that is in the body of the distributor, which is under number one wire too, but I could be wrong on that detail. Double check firing order and clockwise too!

Ok, that takes care of half of the mechanical things. Half, meaning the fuel system on this car is also mechanical. You should have proper spark timing and compression if the others are set.

Hard starting?
Next are we getting fuel? If so, how are the plugs burning any of it? Are they wet or dry after a cranking session?
Any one wet or all? Leaky injector, maybe? If all are wet it means you have enough pressure to open them at least!
All dry means you do not? But pumps can run but is anything flowing? If they flow then why not enough pressure? Could be bad check valves or a run away control pressure regulator dumping it.

HARD STARTING?
In most cases, I have seen bad tank pumps, bad check valves on the main pump outlet or the main pump has a problem getting fed or keeping the line full. Take your pick on which side effects what.

This is where you loosen lines and trace flows and squirts or you get a pressure gauge with fittings to see what the control pressure regulator is doing in between the pumps and the fuel distributor which ultimately lead to those injectors. They have to have 35 psi to push open the nozzles to even fire.

This is a continuous injection system. Mixture is set by the air flap while working with or against the control pressure. The frequency valve that buzzes is also a mixture control that works sort of concert with any O2 sensor equipped car via the ECU. IF IT HAS LAMBDA SOND.

If your car does not, does it have an EGR. That could be stuck open and cause an air leak issue or lean problem that could come and go.

We need to know more about the car in any case. The pressure gauge thing will be involved eventually unless others lead you to a specific component with trial and error logic!

Glad to see you reported your problem away from the LH systems.
The thread heading will bring others to play in your ball-field!
Lucid is real sharp on this stuff. Look for his advice on his past posts if he does not throw his hat out on the mound!
Phil

Phil,
thanks for the response.

Yeah, its a Lambda.

When I did the Injector seals I checked the injectors and they were spraying. (i just put each in a jar and cranked over the car to see if fuel came out- it did).

everything is dialed in on the cam as I just replaced the Timing belt today. with everything set at TDC and the Rotor pointing to #1. What is interesting there is yesterday when lining up the Cam and the distributor, the Crank showed 5*. But now with the new belt I've got it set to 0* at TDC.

My manual doesn't give me a clear answer as to where the advance should be set. as near as I can tell I have a b21f engine, k-jet with the lambda sond.

Honestly It really feels like a miss or per-detination.

Could this be caused by Vacuum leaks? Or is a fuel pressure issue more likely?

Where else, or at what locations can i test the fuel pressure? I don't have access to the correct fittings that to set the gauge up between the Control pressure regulator or the Fuel distribution Block- are there any other spots I can test the pressure?


also, The Plugs were wet and smelled like fuel when I pulled them Pre wd40 test.

Justin

I am glad to know you have the Lambda that way I can reference the green books for my 78 a little.

You are losing me with that 5 degree description too. The crank pulley mark should be on zero for TDC or really close.
More importantly, the mark on the engine casting, that are inside/behind the belt cover, should also lined up to the notch in the belts crank sprocket. That one is true zero or TDC mechanically.
The pulley might be mounted wrong underneath it all. Study the manual about notch alignments if needed.

The dot on the distributors gear face has to line up on the long sheet metal dimple that runs down along to the right side. It's punched inwards. I use a mirror to put my eyes in-line with the dot and tooth. It is a tricky one to get to stay right in place as it easily rotates when tensioned. Do not trust the pointing of the rotor button alone for timing. Use a mirror or you could be off one tooth or that 5 degrees.
You were either on or off now it seems. You can fudge the with moving the distributor on this car if the cam and crank are right.

When I was talking earlier, I thought you had already change the belt and was trying to give you some quick "look it over" references. Setting the belt right is the best and only thing to do if you are suspicious of timing being off.

Vacuum leaks are always a concern. A real lean mixture is never good. Check above the flap of that big rubber boot below the throttle. Make sure its intact, no cracks and is clamped on straight, tight top and bottom. The flap has to be pulled up by air flow. It should only take a whisper or air from the under side to lift it.

As far as the advance numbers you speak of.... there is the initial basic setting of 12 degrees with the engine idling at about 1000 rpm. The rest of the advance happens at higher speeds by some weights inside the distributor or the vacuum diaphragm on these cars. You can only check it with a timing light or inspect the distributor.
What you want to see is for it to jump the mark farther to the left more degrees when the throttle is blipped open quickly.
I think you can only estimate it to be about 27 degrees unless you have a light with the thumb wheel to advance the strobe back to zero and read the difference on it. That number is only from memory but you get the idea.

I built my first advancing light from a Heath Kit many, many years ago. I think they are out of business now.
Harbor Freight now sells them for cheap, IMHO. Mine was still a little better, as it showed the RPM's and Degrees with a release the trigger and I have a circuit board for calibrating it, if that ever needed to be done? I say WAS, as the strobe tube burned out or a transistor. I am not good at troubleshooting electronics, so I sprung for the HFT one to use on my 78, 84, 86, motor home and motorcycles. The 91 does not need one except to check for spark on the wires.

In 89 Volvo and just about everyone else went to the CPS system.
With coils on the spark plugs engine of today, they may be museum pieces of equipment, someday?

As far as pressure points the K-jet is rather demanding to use that set up to know what is what, unless you throw parts at it.
If it's running, I like to blame the fuel injection last on these cars, unless it has had bad fuel. Like in really old gas and it set a lot!
That will kill any car!

I bought the gage set (recommended by Lucid) from a on-line discount tool house for about 85 bucks shipped since I was a new customer. There are deals out there, as they might go the way of the timing light, or not, if we keep using gasoline.

Later on, or sooner than we think, it's going to be about who has the newest & fanciest volt/amp meter with fuzzy logic algorithms to predict battery failure!
Oh, maybe they are going to built in!

Then the question will be, do you need a mechanic for the tires, cooling fans or turbines, a solid state qualified fuel cell electrician or a computer guru?

Tell your kids to start buckling down in school or its throw away time even bigger for them too. Designed right in, all over again! They will never stop paying rent or leases.

No greasy hands....how could some one really live like that....yuck! (:-)

We should have been there 25 years ago! IMHO
That would have been when I was working and could afford it to go fly with the HYBRIDS!

Phil

How likely is that the issue could be caused by a faulty/ old/ cracked/ submerged fuel line between the in-tank pre-pump and the sending unit???

Oh, I meant to comment on "Then the question will be, do you need a mechanic for the tires, cooling fans or turbines, a solid state qualified fuel cell electrician or a computer guru?"

During this morning's television news on the cold weather, the reporter said many of you had to deal with the low air pressure alarm from your car's tires, which even after being aired up persists until a dealer can reset it. Future shock for the likes of us, Phil, who own nothing made this century...
--
Art Benstein near Baltimore

When a clock is hungry, it goes back four seconds.

When my old timing light died it was the xenon tube. Really, there was not much more to it beside the little high voltage inverter - nothing so fancy as a delay for measuring advance degrees. The new one came from Sears, and again, I did not spring for the adjustable version; I should have waited for a visit to Harbor Freight because I paid too much.

Anyway to keep this on topic for the OP, I'll post some links to diagnostic and other research I've done inspired by owning 3 k-jet fueled Volvos. At first I thought the misfire might be caused by a vacuum leak -- running too lean, but later, reading the post and noting what had not been replaced, I figure I'd bring my timing light to this problem first. Easily explained by a distributor cap?

Using the K-jet Fuel Pressure Test Kit

0280 800 001 and 0280 800 021 Notes on Operation

Notes on Breakerless Ignition

Also, here are some recent threads from another forum where quite a few still play with these kjet cars.

TurboBricks brand K-jet Fuel Pressure Test Equipment

Building the Best K-jet Fuel Pressure Tester: What Would You Pick?
--
Art Benstein near Baltimore

Show me a piano falling down a mine shaft, and I'll show you A-flat minor.