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I posted a while back about a no start on my 780. No matter what I do all I can get it to do is crank over. I have fuel and I have spark. Is the fuel getting to the engine? Not sure. All I do know is some days I can go out the garage and it will fire right up within a second or two of cranking, and others it will not start to save its life. I used to drive this car everyday without any issues.
I am not sure where the RSR is on this car as it is different from the 740 turbos??
I am be bewildered by this issue and any help would be greatly appreciated.
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I second what I think Aleekat is talking about - the failure of the hybrid circuit that energizes the fuel pump while the engine is running.
Here are some questions:
Does the car start with starting fluid EVERY time? Did you try to starting fluid at a time when it cranked but did not start? Intermittent issues are difficult because they're not always there when we do diagnostic tests.
Did you jumper the fuel pump relay? Did that have any effect? Replacing the relay won't tell you if you have a failed ECU fuel pump energizing circuit.
I would do this, if you haven't already:
Find a time when it won't start. Then do both of these tests:
Try starting 1) with starting fluid 2) without and 3) with. That will sort of confirm that the problem was there during your test.
Jumper the fuel pump relay and RSR (just to be sure), then try starting. Swap the FI relay back in and try again. Then try each jumpered and FI relay again.
If I remember right, a lack of spark will prevent the ECU from turning on the FI relay. Making sure that you have spark regardless of the starting issue (the starting fluid test) before trying to diagnose something else that relies on it (fuel pump operation).
Good Luck! I hope you get this resolved soon.
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Will start with starting fluid not a sputter without it,
I have jumper-ed the relays like suggested and nothing,
The spark is crisp and blue.
Thank you
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I agree with aleekat that there wouldn't be spark if the rpm sensor quit working, but take a look again at jerryc's earlier post:
1) During starter cranking, the Crank Position Sensor sends timing pulses to Ignition Control Unit (ICU = EZK or REX)
2-a) The ICU uses these CPS pulses to trigger the Power Stage (aka Ignition Amplifier), which initiates spark from the coil.
2-b) At the same time, The ICU also propagates the pulses to the FI ECU, to allow FI operation (no ICU pulses means no FI operation).
The part about no ICU pulses means no FI operation reminds me of the last time one of my 940's RPM sensors quit working (of course, during the NY State inspection on the dyno when they still had it a few years back). The car suddenly died, and the service station had no idea what was going on. It went from fully operational with no symptoms to completely dead. They insisted they had fuel pressure and spark. Only when I supplied them with a replacement sensor on a hunch did the car start and run like nothing happened.
On a more recent occasion, my newly-acquired 93 940 turbo with 75,000 original miles started stumbling and stalling out at stoplights, and losing power while driving. I was almost sure it was fuel related, since the PO had never changed the fuel filter. I had no reason to suspect the RPM sensor because the symptoms were totally different from before and all the electrical components on the car were pretty much in like-new condition. But I happened to have a spare in the trunk, and swapped it out (the old one looked immaculate). This immediately solved the problem.
This makes me wonder if the RPM sensor should be considered more timing-related than ignition-related. Sure, if it completely dies then it would probably result in no spark. But could a partial failure result in partial or out-of-synch impulses to the ECU, which provides incorrect timing or intermittent injection? Just something to consider.
Come to think of it, the only time any of my cars has had an un-driveable condition to date has been related to either RPM sensor or the power stage (I'm at about 600,000 accumulated miles at this point).
Even the youngest 780 is almost 24 years old at this point, and the original sensor would be long past its service life, regardless of miles.
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Now, I tried to remove the RPM sensor, (on top of the transmission??) and after removing the bolt it seems pretty firm in place. Any particular trick to removing it to check it out?
Thanks
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For me, it came out pretty easily once the bolt was out. You may have to use penetrating spray - it's not a good thing if the plastic bracket breaks! Here's the link to the FAQ:
http://www.brickboard.com/FAQ/700-900/ElectricalIgnition.htm#ReplacingHallorRPMSensors
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I think I am just going to have to soak it more in Penetrating spray as I am trying to be rough yet careful and it has not budged at all. I have already ordered a new one as an OEM one is only $25
we shall see.
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You might want to start a new thread about removing the CPS. THe problem is likely due to water getting into the sensor rusting the interior metal parts and swelling the plastic case.
You could try to get a wrench on the square part of the base and gently try to rotate it back and forth.
Dan
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From my experience, the circuit that energizes the fuel pump is dependent on the RPM sensor on the transmission housing functioning correctly. Have you checked/replaced this part? I don't recall seeing it mentioned in the thread, but I've had two of these things fail on me with pretty much exactly the same symptoms. Easy/cheap to replace. I
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Where is that sensor located??
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He said he has spark and it starts with starting fluid. If the RPM sensor was bad, no spark.
--
Post Back. That's whats makes this forum work.
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Disregard my last post about asking the location of the sensor,
Thank you,
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"The only turbo ECU that causes problems is the LH 2.4 563." (extract from ECU failure mode paragraph from below link.)
http://www.brickboard.com/FAQ/700-900/EngineFIComputer.htm#Intermittent_Stalling_Bad_ECU
5th symptom. Sounds like what you are chasing.
--
Post Back. That's whats makes this forum work.
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Ok, I have confirmed it is the injectors that are not firing.
I would love to know where to start!
-Thanks,
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Hello,
I would say that you need to make sure the fuel pump is running while you try to start the car. It’s pretty easy to do if you have a neighbor crank the engine while you feel the case of the fuel pump. Also, you can pinch the return hose and feel the pressure while the fuel pump is running.
Goatman
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Now, when I first turn the key on I can hear the pump or pumps turn on. I took the fuel line at the rail and turned the fuel line on and it filled the little bottle I put it in.
So while cranking the pump should be running?
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Yes. While cranking the fuel pump should be running.
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So if I hot wire it and it starts I know what the issue is.
Now it comes on when i first turn the key on.
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Understand that if the ECU is not calling for the pumps to stay on during cranking, it may not be receiving the ignition signal. This is key information.
Just hotwiring the pump actually tells us nothing, because the fuel pump circuit has been proven by the fact that they run when the key is switched.
Goatman
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Right, I am at the point right now where the problem has been traced to the injectors not firing, As fuel is getting into the rail. I have checked all the grounds and cleaned them as well as tried a bunch of different relays and things.
What are my options here?
Thanks
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I suspect the radio suppression relay. There should be two black relays down near the battery - not the resistor pack which you described in another post as what looked like a pack of ceramic fuses - but rather two squarish plastic relays. One of the two is the radio suppression relay and the other is the relay for the front cooling fan. Each of these relays has four wires connected to it - two large wires and two small wires.
The way the injectors work, they have positive power whenever the key is turned on - that power is supplied to them through the radio suppression relay. The fuel ecu signals for the injectors to fire by completing the ground side of the circuit. I'd suggest that you first remove the radio suppression relay and jumper the two larger wires going into the radio suppression relay together - this will bypass the relay. If the engine starts with these jumpered then the relay is the culprit. If so, you can drive the car with the jumper in but you can't leave the relay jumpered when you turn the car off or the battery will drain.
If the jumper doesn't make the car start then you want to put the ecu in the diagnostic mode and see if the injectors fire - you'll be able to hear them click if they do - check the FAQ's for the procedure to enter the diagnostic mode- you do it by putting the spade in port 2 of the OBD box - just like you do to read any CEL codes that have been set - but by holding the button in the right sequence you will enter the diagnostic mode.
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Jumping the two larger wires did not make the car start, so I went into the diagnostics mode and the injectors clicked rapidly as well as the idle control module, while the injectors were clicking I removed the relay and they stopped verifying the relay works.
So so confused here!
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Is the cam turning? Look in the oil cap while someone turns the key momentarily.
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Yes, the cam is turning and I know this as the timing belt cover is not on it,
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I have swapped the relays but I will try jumping them,
I have never heard of the diagnostic mode before, I will give that a shot,
Thanks I will report back here soon,
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I suspect the radio suppression relay. There should be two black relays down near the battery - not the resistor pack which you described in another post as what looked like a pack of ceramic fuses - but rather two squarish plastic relays. One of the two is the radio suppression relay and the other is the relay for the front cooling fan. Each of these relays has four wires connected to it - two large wires and two small wires.
The way the injectors work, they have positive power whenever the key is turned on - that power is supplied to them through the radio suppression relay. The fuel ecu signals for the injectors to fire by completing the ground side of the circuit. I'd suggest that you first remove the radio suppression relay and jumper the two larger wires going into the radio suppression relay together - this will bypass the relay. If the engine starts with these jumpered then the relay is the culprit. If so, you can drive the car with the jumper in but you can't leave the relay jumpered when you turn the car off or the battery will drain.
If the jumper doesn't make the car start then you want to put the ecu in the diagnostic mode and see if the injectors fire - you'll be able to hear them click if they do - check the FAQ's for the procedure to enter the diagnostic mode- you do it by putting the spade in port 2 of the OBD box - just like you do to read any CEL codes that have been set - but by holding the button in the right sequence you will enter the diagnostic mode.
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Try this;
-----------------
"Start-Run Sequence LH2.4 or REX
1) During starter cranking, the Crank Position Sensor sends timing pulses to Ignition Control Unit (ICU = EZK or REX)
2-a) The ICU uses these CPS pulses to trigger the Power Stage (aka Ignition Amplifier), which initiates spark from the coil.
2-b) At the same time, The ICU also propagates the pulses to the FI ECU, to allow FI operation (no ICU pulses means no FI operation).
3-a) The Fuel Injection (System)* relay (previously energized at Key On) powers the AMM, IAC, ECU, Injectors, and Fuel (pump) relay coil + side.
* The System relay is in the white case with the Fuel relay.
3-b) When ICU pulses are received by the FI ECU, it "energizes" the Fuel relay by grounding the relay coil (– side) to run the fuel pumps.
When all these things work, the engine runs until the Ignition is switched off, which in turn shuts down the FI system.
Determining whether or not there is spark at the plugs (2a) — and whether or not the plugs are getting gas (3b) — makes a good no-start "starting" point.
For example, if 2a fails due to a bad Power Stage/Amplifier, there will be a no-start with gas-wet plugs. If 2b fails (practically never) symptoms will be Fuel-related: a no-start with spark at the plugs, but plugs remain dry.
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63. "
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Well I have been tinkering around a bit. Seems as though I have fuel to the rail and after cranking the engine for a few seconds I have dry plugs. Ether is of no use to start the engine????
Could this problem be the CPS?
Thanks,
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There is fuel to the rail, but it appears Not to the cylinders. Thus, it'd be an injector issue, or insufficient fuel Pressure. I recall some time ago someone had fuel and spark and timing, but a clogged filter didn't allow enough pressure to get fuel past the injectors. can you pull one/some of the injectors and see if they're spraying?
If it was the cps there'd be no spark; is there spark at the plugs?
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Well I have it firing on ether, so I imagine the injectors are not firing.
What common issues should I start with?
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Did you ever locate the rsr? Do you have a pic of the engine compartment that you can upload to imageshack or photobucket etc?
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Yes, I'll send a pic along,
It appears on these 780's they put it down in front of the battery and like a normal 700 it is next to the fan relay and I did swap them with no change.
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Have you pulled the cap off the Fuel Relay, i had an issue on my 780 where it was intermittantly working, i would just reach in and push the relay contact and she would fire up. pretty easy check since you can sit there and do the test while starting it.
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Which relay would be the "Fuel relay" ??
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The fuel pump relay is in the center panel below the radio.
The rsr, Radio Suppression Relay, which is actually the fuel Injector relay, and on a turbo also powers the coil, is black, has a square plug, and as I said is on the inner left fender above and behind the battery. That's where it is on my 4 turbo cars, and all the others I have seen and/or worked on.
The 4 white ceramic item is a resistor for the low impedance injectors that most or all turbo's use. I have never heard of one failing.
Search for lucid's 'Start-run sequence'. It's the best thing out there for your issues.
Oh here, I found it. IMO, print this out and keep it in your car.
============================================
"Start-Run Sequence LH2.4 or REX
1) During starter cranking, the Crank Position Sensor sends timing pulses to Ignition Control Unit (ICU = EZK or REX)
2-a) The ICU uses these CPS pulses to trigger the Power Stage (aka Ignition Amplifier), which initiates spark from the coil.
2-b) At the same time, The ICU also propagates the pulses to the FI ECU, to allow FI operation (no ICU pulses means no FI operation).
3-a) The Fuel Injection (System)* relay (previously energized at Key On) powers the AMM, IAC, ECU, Injectors, and Fuel (pump) relay coil + side.
* The System relay is in the white case with the Fuel relay.
3-b) When ICU pulses are received by the FI ECU, it "energizes" the Fuel relay by grounding the relay coil (– side) to run the fuel pumps.
When all these things work, the engine runs until the Ignition is switched off, which in turn shuts down the FI system.
Determining whether or not there is spark at the plugs (2a) — and whether or not the plugs are getting gas (3b) — makes a good no-start "starting" point.
For example, if 2a fails due to a bad Power Stage/Amplifier, there will be a no-start with gas-wet plugs. If 2b fails (practically never) symptoms will be Fuel-related: a no-start with spark at the plugs, but plugs remain dry.
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63. "
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I will go through it a little more tomorrow and see if I can stumble on something, I will take a few pics as well. I have access to a free pile of old volvo's and I have replaced virtually every relay inside the car in hopes of solving the issue.
Like I said I will check these things and get back to you,
Thanks again
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Instead of just replacing parts, diagnose the problem and then replace the failed part. I have a lot of people think they installed a good part and installed a bad one to even further complicate the diagnosis. There is plenty of info on this site to find your problem. Test light and ohm meter are two invaluable tools that will find any electrical gremlins.
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I mean I am not just arbitrarily replacing parts, I was merely swapping parts for the purposes of diagnosis.
thank you,
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I have fuel and I have spark.
How do you know that, exactly? Is there spark at the plugs?
Try to fire it, and after it doesn't start take out the plugs and see if they're wet. Or, take off the injectors, put them in containers such as small plastic bottles, unplug the coil so there's no accidental fire, and turn it over; see if fuel comes out of the injectors.
RSR may be over the battery up behind some wiring.
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Plugs are visually firing. I just re did the timing to make damn sure that was not the issue.
Is the RSR the thing that looks like 4 ceramic fuses in a cage next to the battery? I was at the bone yard today and could not find another volvo with that "fuse" looking thing.
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"redid the timing...
spark timing cannot be 'redid' on your car; it's controlled by the computer. Do you mean valve timing/checked the belt?
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Yes of course I mean valve timing, after owning several rear wheel drive's over the years I have become rather good at timing.
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The fuel relay is a white one behind left of the ash tray in the console, Check the FAQs for help. The ceramic items are a power distribution block. Not sure of the year and engine you have, makes a difference for Bosch systems so we canhelp guide you to the gremlin.
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I have swapped that white relay out with several second hand ones with no change.
My 780 is a 1990 with a B230FT
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Will it start with starting fluid? If yes, then you know it's in the fuel delivery.
If no, possible plugged cat?
These are pretty basic. Fuel, spark, compression and spark at the right time.
I do know the b230ft absolutely needs a good solid 12volts, and hates any type of air leak.
--
Post Back. That's whats makes this forum work.
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Yes it does start with ether, never had any other trouble starting this car before, I get fuel to the rail and when tested with the OBD I can get the injectors to click
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My 88 B280F with LH2.2 is acting similar, however, I found two injectors plugged as PO had never changed filter so now am in start ok and then go to surge and miss mode. Your symptoms also could be a failing tank pump. works ok when tank full and pressure pump under car can draw fuel, however, if tank is down gets iffy on fuel delivery. Check pressure under car from tank pump and then at rail for pressure pump because of ease of access.
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I will check that, however it just seems strange that would be the issue as I have plenty of fuel getting to the rail.
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My understanding is to date you have ignition spark and fuel, yet still will not start. Even with computer set timing, you can verify correct timing with a timing light. Correct timing and spark leaves fuel and air problem.
If you have fuel to the rail, then the next stop is check the injectors with a noid light for the firing signal from the ECU and then pull the injectors with rail out (watching the fragile metal tip when you do) so you can easily test them where you can see and separate each. Injectors are held to the fuel rail with a c-clip.
The injector rail is easy to pull, use the wire bails to release each injector connector, a ten mmm socket on the two bolts going into the manifold and the two fuel lines (make sure you hold both sides of fittings and pull wrenches together)and pull straight up. The drivers side (Cyl 3-2-1) is easier to pull. Install with injectors secured to the fuel rail as it is too easy to cut an o-ring on the top of the injector with the rail caps. Put a little silicon grease on the o-ring for the manifold to help the injectors slide into the hole when you reinstall. Also clean the injector ground wires ring terminals that go under the bolts.
Out of the car you can check each injector by putting nine to twelve volts across the two pins and using either a can of starting fluid and a straw (cleans junk out also) or low pressure air 40 lb or less as that is normal range of fuel pressure. If they test ok and open, both click and pass fuel, forget about the other side injectors as they are probably ok also, and look again at the fuel pressure.
Fuel pressure culprits (in order of failures encountered): Radio suppression relay (RSR), fuel pump relay, fuel pressure regulator, fuel filter, pressure pump, in-tank pump, in-tank pump hose rarer-pressure pump check valve, rarest-bad injectors as determined by the commmuity experience. Engine harness not listed as 88 is about when better harnesses were cut in and yours is a 90.
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I have taken the rail off and tested the injectors, both manually and with the OBD port,
The RSR is not the fault as it clicks and activates when the OBD test is conducted and when you unplug it the injectors stop so that is working. And I have tried several other's
Tried jumping the pump so we know the relay is not the issue,
Filter is recent and I am getting fuel to the rail so that does not seem to be the issue.
I have not checked the intank pump, but If I am getting fuel to the rail could that still be an issue???
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"I have taken the rail off and tested the injectors,"
Did fuel squirt out of them?
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When fuel was put in one side of them and when power was given to them on the bench yes,
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Oh, so they were removed. We pulled them out but still all attached to the rail etc and put a towel under them, and turned the car over. Visible fuel came out.
Doing it this way ensures that the car's entire system is in play; this may help you. We pulled the connector to the coil so there could be no spark while this was happening, so no chance of starting a fire.
In this case, the cam gear pin had broken.
It seems you have fuel, spark, and compression, and the cam is turning. So if you do the above test and there is still fuel, there is something very odd going on.
Have you checked that spark timing is happening correctly?
Also, I wonder if the cam belt skipped some teeth, so even though it's turning, compression is not happening at the right time either.
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Well the strangest part of all this is the fact that it started and ran once and I drove it around a few weeks ago stopped at the car wash washed it then started it up and drove it home, next day would not start and here we are.
It will start with ether and the first time this happened I re did the timing belt to make sure it did not slip like suggested.
It just seems the injectors are not firing, but they are firing when tested????
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Again, test them in situ, that is connected to everything in the car, but squirting onto a towel or similar. You need two people to do this, one to turn the key and one to watch the injectors. It'll be immediately obvious. Immediately. No waiting; the fuel comes out right away or it doesn't.
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I will have to give this a shot as soon as I have someone around,
thanks,
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