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I have no spark at the spark plugs with a rex coil pack , changed the distributor cap and rotor, I also changed the coil with another one still no spark. How can I check for power going to the coil. Thanks!
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Be suspicious of a bad coil producing a weak spark, possibly coupled with incorrectly gapped or bad plugs or bad contacts at the coil. See the following for appropriate testing of your Rex/Regina coil
https://volvoforums.com/forum/volvo-240-740-940-12/bendix-regina-coil-test-10640/
https://www.brickboard.com/FAQ/700-900/ElectricalIgnition.htm#ReginaCoilPackCleaning
Definitely check out timing belt alignment and condition. Have you got access to an okd fashioned timing light? That would be a quick and easy check of the timing. If it's around 10-12 deg BTDC you're probably good to go on timing belt alignment and the harmonic balancer not slipping. Othewise set the crank TDC using a probe in cylinder number one, remove the upper timing cover and check the cam sproket timing mark. The intermediate shaft sprocket for the oil pump doesn't matter, only when there's a side mounted distributor.
Just for the heck of it, double check the lower ignition wire from the coil is still fully seated in the disturbutor. Sometimes it's easy to think they're in all the way, but it's just the edges touching.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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As long as I'm thinking about it, and as I may not be following your next reply, if the coil with the internal power stage checks out (please do that first), then double check that you have a good strong spark from each plug against the block. Do it in the dark to see how strong it is. Double check the plug tips for an approx .028" gap (.025"-.030").
If that all checks out then you need to go back and re-think the fuel side.
You said you've got decent fuel pressure, which I presume means you got a squirt of gas at the Schrader valve. That still leaves the issue of adequate fuel pressure and delivery.
Start by making sure you can hear the in-tank main pump running when you crank with the gas cap off, listening down with a tube if needed. I'm not sure if Regina spins up the pump for a moment when you turn the ignition key into the On position (KP-II) the way the LH systems do, so you can try listening for that first in a quiet environment without needing to listen down the filler neck. If you hear the pump buzz for a moment then you can assume the fuel pump is okay.
Next check for injector operation and worry about fuel pressure and delivery last.
There's an easy and simple way to check that the injectors are being operated. There's an OBD test you can perform at the diagnostic socket to confirm injector operation, which would remove the ECU and injectors from the equation.
Perform Diagnostic Test Mode 3 (DTM 3) at ECU port 2 (socket 2 in the "A" block) as described here in the FAQ:
https://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm#FuelInjectionandIgnitionDiagnosticCodesi
The injectors (tic-tick), electric fan (low/high) and idle control valve (tick-tock) and vapour solenoid valve if present (faint ticks) will be continually operated in a cycle until the test is stopped. Put your hand on each injector to confirm the ticking injector and that the ticks are more or less uniform between injectors. If that checks out then after some cranking, pull each plug to check for evidence of fuel, either wet plug or smell of gas through a tube.
If your socket has connector issues such as you suggest and the LED won't function when the button is pressed then you may need a bridge between deep in the socket and the probe or else repairing the probe wire connection, bypassing the block to the connector wire underneath.
To confirm adequate fuel pressure, you can crudely do it with a tire gauge at the Schrader valve -don't use an expensive gauge and dry it thoroughly afterward. Anything over around 30 psi should be okay. Best to do it after a bit of cranking so you're not just measuring residual line pressure.
Somewhere in all the advice you've been given should be evidence of the likely problem.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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Hello, All
After Talking with BillB ,And using manuals that went a bit further than the Hynes
book. I am thinking that I have a bad power stage or a bad control unit . Having no codes on OBD. Looking at the wiring diagram it shows a connection from the crank positioning sensor to the power stage. This could explain the out of time thought. If the power stage controls trimming at all. So I`ll ask if anyone knows how to check a power stage or if it's being sold still.
Thats a rex power stage. Thats sparks a grounded plug alone but will not run a spark through the distributor cap We. got good coil pack and CPR sensor readings.
Any thoughts appreciated Steve
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With Regina engines, the CPS does not connect to the power stage, it connects to the Rex i ignition controller, which then passes the signal on to the fuel ECU. The ignition controller has a control line to the combined power stage relay and coil to call for spark and adjust the timing advance.
Are you looking at a Renix system? It does have the CPS going to the combined power stage and coil, with no ignition controller and presumably only used on carb'd engines. Maybe check my reply just now to Bill elsewhere here in case I'm missing something in your symptoms or diagnostic testing you've done. I'm very much thinking fuel side at the moment.
The Hayne's wiring diagrams can be difficult to use. Most other manuals only have schematics, good for basic connections, but not so much for years, engine versions and detailed testing. Better for you to find a Volvo green manual online for a year close to yours, either 740 or 940. You're near the end of the 740 models (and possibily a non-North American market car?) and now more divergent from the end of the 240 series and the beginning of the 940 series than many are familiar with here, so things maybe a bit different from what some of us like me are familiar with.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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Dave you are right on . I was looking at the wrong diagram . Looking at it closer shows that a carburetor is included .Renix. I paid 1200 $for this car 4 years ago and since I have owned it, I have had no problem except for a bad connection at the radio suppression relay . It has some money in the bank coming to it .
So, I went into the Auto Zone and bought a power stage for 70 $ delivery later this week
Steve, bike cycle
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Hello,
Well, I got the 90 740 running again. I installed a rebuilt ignition ECU and the engine fired right up. I hope that this was the problem and not a connection issue. I'm going to go with it tho. What was learned? I wish I could say.
I learned that there is a support group that was helpful in a lot of ways. I will be looking in on the Brickboard more often.
I need to get back to the 66, 130 project. Points & carburation.
Thanks, Steve
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This assembly was called a power stage in 1989 Rex
and in 1993 Rex "Power amp/Ignition Coil"
The pinout in the Volvo pocket data book is for the B230FT
that has separate coil and power amp
Steve, Put the coil back in and test DI assy with your meter.
=========================================================
Rex-I Distributor Ignition (DI) system (B230F) or B230FB
B for Bendix
schematic from 1993 940 manual
Pin out for Power amp/Ignition coil 4/26
_____________ HT_____________
C__B__A_____B__A_____C__B__A
1__2__ 3_____4__5
1 To Tach red/white
2 Signal ground 31/32 black
3 +12vdc from ignition switch blue
4 from ECU pin16 control voltage green
5 Power ground 31/33 and ECU pin 20 brown
To test coil pack
Rex-I Bendix (#1367438)
Measure between primary
Pins 1 & 3 _____ 0.5 - 0.6 ohms
Measure between secondary
Pins 1 & HT______5.0 - 7.0 K ohms
HT = High Tension wire to distributor
==================================
It's interesting that the B230FT the RSR shuts down
the 12VDC to fuel injectors AND the ignition coil
The Rex RSR shuts down only the Fuel injectors
Steve was getting wet plugs so it still looks like ignition.
His connections between the coil and the 5 pins are bad
and maybe the power amp is the culprit here?
Can it be serviced or replaced separately?
The coil is available separately.
I asked Steve to check for no air in case he sucked a plastic
bag or a raccoon into his air intake, all is well there.
I don't have the engine schematics for 1991 so maybe Steve has
the Fuel relay and RSR to worry about which he can test by
making sure he has +12VDC at pin 3 blue wire
Bill
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Efforts to troubleshoot rex coil pack Part 2
I goofed and would like to delete the test points for the coil.
It turns out that the coil pack pins go directly to the Ignition amplifier
You must remove the coil to test the primary and secondary windings.
The resistance values OK per Volvo pocket data booklet.
Dave Stevens please send me an email, I lost yours.
Bill
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Hi Bill. When I said ignore the previous email, I meant the post notification you get from the brickboard immediately after the post is first submitted, if you're subscribed. I often heavily edit posts to fix mistakes, delete misunderstandings or add content while investigating, so what you see posted is not what you get emailed with the reply notifications. I've told Jarrod I would prefer either restoring the old notification delay until the edit period has expired (requiring an event queue that Jarrod was trying to eliminate), or better still just to immediately send the link and only the first sentence or so of the reply, much the way you get Facebook notifications. The brickboard is showing its age, but still the most valuable Volvo forum out there for keeping our bricks rolling.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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(geez I'm getting tired of the post edit system here for accidental duplicate posts and the inconsistent re-edit buffering)
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Good advice regarding how to check a Rex coil. I suggest electrical testing both the coil and the coil wire at the distributor cap end.
Shot in the dark: Didn’t read all the other posts. So this may duplicate or not be applicable. I was trying to track down a no start problem on my 95 850 some time ago. Went through all the ignition stuff. Turned out it was flooded. Does it crank okay? If so, crank it and keep it floored for about a minute to check that out. Flooring it is the proper technique to start a flooded fuel injected engine.
--
Will I buy another Volvo??? We'll see....
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"...How can I check for power going to the coil..."
From what I decipher from the wiring diagram it looks like the blue wire provides the 12v power source to the coil pack.
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Hi Chris,
Blue wire is the +12V to the power stage
Green wire is signal (control) wire from ICU to the power stage
I haven't worked on a REX but would inspect the power stage connector
to make sure all is clean and tight. Some Penetrox (zinc paste) would be good long term lube, better than dielectric silicone, since it deters electrolysis between unlike metals.
I have the Ignition manual: Volvo 740 1989 TP2031397-1 Ignition (18MB)
Provide an email and I'll send.
Bill
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Ahoy
I'm going on suggestions from Dave Barton and Ron Qwas about Penetrox.
Yes Zinc is a conductor but the zinc paste isn't supposedly.
I'm testing a thin film of Penetrox-D in my CPS and AMM connectors now.
So far so good, but way to early to be confident.
My guess is that after market CPS likely have cheap unplated connectors
and dis-similar metals promote electrolysis and bad news for connectors.
Why would a CPS quit and start working again? It's a simple pick-up coil?
Connectors are a weak point in geriatric wiring.
Going near bullet connectors with solvents can destroy them.
DeOxit has an interesting new grease that you can get a tiny free sample
I'll try that on the connectors if the engine resumes it's chronic long term
bad habit of gagging/outright quitting reported by the previous owner.
It goes for weeks or many months between it's evil behavior.
How can I e-mail you for some off topic stuff?
Bill
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Hi Bill ,This is Steve with the ignition problem on a 740 e-mail is soltez@gmail.com I'm devoting my Friday to figure this out.
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I will try all suggestions. I have had problems with the connections at the radio suppression relay before. Maybe it's a similar issue Q. does voltage need to run through the OBD. I will try to get a signal regardless. Thanks again . I now have more to go on. My name is Steve by the way.
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Hi Steve,
I Like Chris's suggestion, but you said you swapped power stages?
When you do this stuff pay close attention to the connectors.
Look to see that the pins are not damaged.
Clean and use a little Penetrox or dielectric silicone lube.
The OBD port is for diagnosis. It reports problems.
See if you can get a report from OBD port 6.
Make a connection to the (I'm guessing) pushed back pin
in the OBD connector block to the jumper wire.
Bill
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I got the # 6 connector to make contact with the insert now so I can get a reading. It's an endless rapid fast flash. I don't think this is good. I have battery voltage at the coil pack(blue wire) tho. Any thoughts on the flashing lights.
Thanks ,Steve
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Hi Steve,
That's weird, maybe someone knows.
Try disconnecting the battery for ten minutes and try again.
The idea is to reset the ICU.
If you have a Volvo radio make sure you have the code to enable it.
Bill
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Hello,
I got the connections figured out on the OBD Making sure I had a positive connection this time. What I was doing was performing a function test with the continuous flashing light. So I now routinely get a 1 1 1 no problem . Tried 3 times always the same. Good.
Following the green book, I was taken back to checking for spark .No spark with pulled plug grounded on head. then taking the HT wire off the cap from the coil and running it through a plug grounded on head we see a good spark. The book says and it makes sense the problem is with the cap or rotor. I have tried 3 different caps & rotors , I had cleaned the ground to the head. and still no spark through the cap but a good spark just through coil to cap wire. Tried wires and plugs from another running engine. Rotor turns .( I could handle a trimming belt. joke) injectors firing with fuel pressure.
I guess I will turn to the ECU with the thought that the spark from the coil alone
is false hope. Any thoughts would be appreciated. thanks ,Steve
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So this problem started while driving the car and not just after any work was done, is that correct?
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Yeah Chris, Driving at highway speed on a dry 65-degree day . No sputter just stopped running . Its been a great car even with 265,000 clocked. I have a good Fluke multi meter and the caps have continuity . I don't know how to check the rotor for sure . No continuity from the center to the outside edge. It may be a diode or something between the center pick up and outer edge. I tried 3 different ones tho.
Back to it .
Not supposed to but I'm starting to panic !
Steve
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I believe the rotors do have some resistance built within, like maybe around 1000 ohms??? But I could very well be wrong so possibly another respondent could straighten me out there. Maybe your Fluke meter wasn’t set on a sensitive enough range to detect continuity???
Anyway, are you using Bosch rotor and cap?
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Hi Chris, It`s something It was just suggested to check the rotor and resistance and they were both 1000 as you said. Still trying to figure the thing out could it be possible that it jumped a tooth or lost timing some how else? I have a old Bosh cap and rotor that was older but worked that I tried.
Thanks, Steve
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Actually I had given some thought to the possibility of the timing being out of whack. That’s why I asked if it had recently been worked on.
Being a 1990 740 I am assuming you have the cam-driven distributor rather than the side mounted intermediate shaft-driven version.
First off, you have verified that the rotor is turning so you know the timing belt must still be in tact, but you don’t know if it may have jumped a few teeth.
Normally you could use the timing marks on the crank pulley to verify TDC but, unfortunately, the 740s use a two piece pulley that consists of an inner section that’s keyed to the crankshaft and an outer ring that carries the accessory belt, and those two sections are isolated from each other with a rubber filler. With old age the rubber starts to loosen and the outer pulley ring can spin on the inner section, causing the timing marks unable to accurately indicate crankshaft angle. You can use a plastic straw inserted in the #1 spark plug hole to “feel” when the piston is at TDC. You may be a degree or two off but you will be close enough to TDC for this exercise. Now look at the crank pulley timing mark and see if it’s at, or very very close to, TDC. If it’s at TDC then you know the pulley has, most likely, not spun and you can now rely on it for an accurate crankshaft angle reading.
Remove the upper timing belt cover and see if the cam sprocket timing mark aligns with the index mark inside the rear timing belt cover. If it’s nowhere close then turn the crank one complete revolution and recheck the cam sprocket timing mark alignment. If it still doesn’t align then something somewhere has slipped - possibly a loose belt, stripped belt teeth, or sheared woodruff key between the crank pulley and the crankshaft.
You will also want to check the relationship between cam timing marks and the rotor position. When the cam and crankshaft are at TDC the rotor should be pointing to the #1 distributor cap contact. If it doesn’t match up then it’s possible the cam sprocket-to-cam keying has failed.
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Hi Chris,
Nice post!
I talked to Steve on the phone earlier, and he went off to check the timing
of the T-belt. It looks like the rotor is out of time with the spark.
He checked and the rotor and cam is turning so the T-belt is intact.
Like you say it may have missing teeth or have jumped time?
He has a parts car, so maybe he should swap the harmonic balancer and recheck timing?
Best regards, Bill
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Hello, I took the front covers off the front of the engine as if I was doing a trimming belt change. All 3 points lined, up with #1 piston at TDC on compression stroke. Took the cap off again and the rotor was aligned with the caps # 1 plug. So, I still think that its in time. Unless the ring on the flywheel changed somehow.
I then went back to the spark. I changed the batterie with the thought that I had enough voltage to fire just the one spark plug alone from the coil, but maybe not enough voltage to run through the distributor cap. Still no good . I even tried the jump setting on the charger , No good .
From the posts I guess I turn back to cleaning contacts. This problem is so frustrating. Thanks for the suggestions
Steve
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Hi Steve,
Did you see the comments about the harmonic balancer (crank pulley)?
That is two sections attached with rubber, and known to slip.
That would be your timing mark on the crank pulley going haywire.
I don't know how far it would need to jump to kill your engine,
other's might comment.
You could swap it.
Bill
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Hi Bill. He said he checked it against cyl #1 TDC. Steve (OP) said he pulled the timing covers, plural, like he was doing a belt change. I'm not sure why he would loosen all the drive belts and pull the harmonic balancer to get the lower timing cover off. If you do cyl #1 TDC and the pulley marks are aligned to the lower cover timing zero mark then all is well with the harmonic balancer and crank sprocket alignment and no need to get at the sprocket to check for a broken key.
As for a jumped timing belt tooth, you'll usally get rough running, not a sudden stall out. Even two jumped teeth and you'll still stumble and run. Jumped teeth are usually a sign of a misadjusted tensioner or a badly worn tensioner pulley. With the upper timing cover removed, a belt that's looser than normal, especially on the exhaust side, is a sign of misadjustment. The other possibility we worry about is a stripped belt tooth. The belt would normally be well beyond its change interval and a close inspection would reveal rubber fractures at the base of the teeth (there should be zero evidence). I've never used a cheap aftermarket timing belt (only use Continental) so don't have experience if other brands have a higher failure rate.
Normally when there's a sudden stallout at speed, it's the CPS. But there wouldn't be spark or injection during testing. The OP said he put in a known good CPS, meaning used. A used CPS may have been working okay prior to removal, but during removal, handling and re-installation the cable can crack -just happened to my old spare CPS, leaving me without a spare when the installed one finally went.
The CPS coils rarely if ever fail, it's the wiring or shield that breaks after years of flexing and stress, typically evidenced by damaged cable insulation, like a stress fracture way down at the bellhousing, at the mid-cable plastic standoffs, or scuffing against the return pipe to the water pump or the EGR to exhaust manifold pipe (if the standoffs are missing). When suspect, I normally remove the cable for a proper inspection and flexing it at the usual stress points (if it's borderline, that usually splits them). For aftermarket CPS, the only CPS I trust to have Volvo quality wiring and cable insulation are Bougicord (France, supposed OEM, now a global manufacturer, eg. Mexico) and Facit (made in Italy, looks really well made, my goto CPS now). Facit is apparently an OEM for BMW and Mercedes.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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Hi Dave,
I worked with Steve on the phone earlier and found
from his VIN nr. he has a 1991 B230FB (Using Volvo pocket data booklet)
he has two CPS that both coils resistance check OK
Volvo has one CPS -1991 and another 1991-
slightly different resistance and impedance values
He thinks the engine is in Time #1 at TDC and timing marks OK AND rotor at #1 plug.
My 740 manual is for 89 and the DI unit may be different in his 91
the Volvo pocket book says measure primary at 1 and 15 and secondary 1- to High
and the drawing and parts he has don't show pin numbers
looking up his DI part nr. 1346788 you can find just the coil for about $25
and it looks like he has an open port from where the "- coil" pin plugs in to the
DI unit where the chassis connector goes.
What craps out in the DI unit that the coil connection is lost?
The coil primary and secondary windings seem OK
are there any series components in the DI unit from coil to chassis connector?
Do you have wiring info for the 1991 B230FB Rex Ignition?
Thanks, Bill
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Hi Bill.
[Edits below from the emailed copy you received. I misunderstood. Steve has two RPM sensors, not in the same engine, duh me.]
I'm admittedly not familiar with the subtleties of either the FB version or Rex/Regina, let alone all the carb'd K versions.
I've got the same '89 740 manual as you. The only Rex i ignition diagram is for B230F/B234F. I'd want to look online for a '93 940 manual for other possible Regina variations if I couldn't find a '90-92 740 manual. I'm assuming Steve's B230FB Rex i system can't be far different from the more common later 940 B230F Rex i. Maybe check a a '93 940 manual for Rex i differences. There's no Rex/Regina in my '95 940 manual. Note that these are Volvo North America manuals, so may not fully cover all the versions.
CPS testing using resistance does not confirm operation or the integrity of the shield, basically only a wiring break or short, usually evidenced by cable damage as I noted. I didn't realize there was an early and later CPS sensor for Regina. In any case, seems the two CPS Steve has are both okay and that's exactly what I would expect if there is spark.
If the coil (and a spare?) check out and there's good spark (presumably checked at all four plugs) then the ignition controller is alive and if there's no Check Engine light in the cluster then there's little chance of finding anything other than a 1-1-1 at port 6, whether or not Steve can get the diagnostic socket to co-operate.
I think you may have Steve chasing too far up the wrong tree at the moment in terms of likelihoods. This is a stall-out and no-start condition, not a running issue, so presumably something very fundamental. I'll give you credit, when you get focussed on something, you leave no stone unturned even if not a trip hazard.
A good spark at the plugs says forget the ignition side to me until you've exhausted other possibilities. Or am I being misled? There's been no suggestion it slowly died with a stumble and/or tries to catch during cranking. I'd expect basic testing starting at the engine to quickly point the finger in the right direction. I hope Steve now pursues the fuel side testing I've recently suggested before coming back to the ignition side.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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Hi Steve,
If you have a good spark at the HT wire from the power stage
and no spark at the plug wires.
Confirm the rotor is turning.
Use dielctric silicone on the plug wire ends so that they seat 100%.
Are these OEM dist caps?
You can use an ohmmeter to see that the distr. cap center pin is connected to the rotor contact.
BB
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Greetings, Steve.
Have you tried opening up the coil pack (two torx screws) and cleaning the internal contacts? It’s somewhat of a known failure point.
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Yeah ,I did that, seeing it the FAQ section. Gotta get to work today tomorrow I am going to get a chance to look deeper. Thanks. What a great feeling to have folks willing to help out .
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Hi,
Check fuse 1
See if you have any OBD codes.
Post back, Bill
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Hi Bill, Thanks for the reply . Im new to posting so please hang in there. Fuse 1 is good. OBD # 6 ignition nothing no light at all. #2 no fault, with flashes 1 1 1 and it
dose the relay and injector etc. check as well . I should add I have fuel pressure
and I switched out distributor cap/rotor . plus installed a known good crank positioning sensor. It just cut out at highway speeds.
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Hi ___?___,
Welcome to Brickboard.
Don't throw parts before diagnosing the problem.
OBD port 6 (ignition) is kaput? That's bad news.
I had my OBD port do that and found that the bullet connector had failed
I'll give you repair/parts details later.
The female connector at port 6 can be dislodged with the neoprene or
whatever that stuff is to hold the female connector so when you plug the black
lead into port 6 it makes a connection.
Don't take the connector apart yet
First look in port 6 and see if the female connector looks like the one in port
2. See if port 6 connector is pushed down , loose, floating free.
see if you can jury rig the black lead to the port 6 connector and maybe
get OBD report?
Let's try to get a readout from the ignition ICU to point to the problem.
While you have the hood open, confirm that the ground wire/s to the intake manifold are solid and not loose or broken. Those are key for the ICU.
(It looks like maybe only one signal ground for REX)
Post back, Bill
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