Help! 1991 240 wagon
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My first thought when the car died was that the timing belt had failed or slipped. I checked it and found that a piece of the upper belt cover had broken off and fallen into the lower cover. I thought I had it, the broken bit had gotten between the crank cog and belt and allowed it to slip. I re-set the mechanical timing but no dice.
Next I'm going to check the ignition codes and then the cold start injector. The cylinders seem awful wet even after a short cranking.
Next I'm going to check the ignition codes and then the cold start injector. The cylinders seem awful wet even after a short cranking.
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you can verify the operation of the individual fuel pumps by using a jumper wire across the appropriate fuses at the fuse box. that way, you can specifically operate one at a time to verify if they are pumping. won't tell you whether they meet spec output, but will tell you if one or the other isn't operating at all.
these aren't much different than toyotas of the same vintage. throwing parts at them is rarely successful. test and verify faulty components before replacing. volvo had about the same reputation for longevity as toyota at the time. the factory parts were pretty good, and gave long service.
these aren't much different than toyotas of the same vintage. throwing parts at them is rarely successful. test and verify faulty components before replacing. volvo had about the same reputation for longevity as toyota at the time. the factory parts were pretty good, and gave long service.
Last edited by wallytoo; Aug 29, 2019 at 10:34 AM.
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does not appear to mirror your symptoms so your best bet now is to explore other avenues (as in act1292's suggestions)
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I pulled the cold start injector/valve today. With the wire connected I cranked the engine, no leaking or spraying. Temperature here today in the high 90's. No ignition failure codes were found. Don't have a 15kohm resistor to test if it opens, Still not starting.
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Given all of your posts (wet plugs, strong spark), this seems relevant. If you have a spark and gas then I would expect it to fire - at least cough. I have had a no-start condition occur on my '90 240 that occurred because the timing belt has slipped (or wasn't set properly) on the half-shaft. This led the rotor to be off at least by 35-40 degrees. Occasionally it would fire (or backfire) on a cylinder.
To check for this, rotate the engine until cylinder 1 is TDC. Pop off the distributor cap and see where the rotor is pointing. It should be pointing at the #1 cylinder spark plug wire. If not, then the timing belt is not timed right. Keep in mind, this only verifies timing on the half-shaft - which only powers the distributor and oil pump. To verify the valve timing, you must remove the timing belt cover.
To check for this, rotate the engine until cylinder 1 is TDC. Pop off the distributor cap and see where the rotor is pointing. It should be pointing at the #1 cylinder spark plug wire. If not, then the timing belt is not timed right. Keep in mind, this only verifies timing on the half-shaft - which only powers the distributor and oil pump. To verify the valve timing, you must remove the timing belt cover.
no mo volvo
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From: 37 North on the left coast
normally the cold start injector only sprays for a couple squirts when the engine is cold and cranking. not leaking is good.
I'd probably get a 'noid light' and plug it into one of the main injectors, and crank it, and make sure its just blinking and not steady on and flooding. all 4 injectors are wired together and fire together, so you only need to test one.
this is a 1991? there's no codes on pin 2 or pin 6 of the diagnostic block? pin 6 is the ignition, pin 2 is the fuel injection.
see Engine and OBD Diagnostic Codes
I'd probably get a 'noid light' and plug it into one of the main injectors, and crank it, and make sure its just blinking and not steady on and flooding. all 4 injectors are wired together and fire together, so you only need to test one.
this is a 1991? there's no codes on pin 2 or pin 6 of the diagnostic block? pin 6 is the ignition, pin 2 is the fuel injection.
see Engine and OBD Diagnostic Codes
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normally the cold start injector only sprays for a couple squirts when the engine is cold and cranking. not leaking is good.
I'd probably get a 'noid light' and plug it into one of the main injectors, and crank it, and make sure its just blinking and not steady on and flooding. all 4 injectors are wired together and fire together, so you only need to test one.
this is a 1991? there's no codes on pin 2 or pin 6 of the diagnostic block? pin 6 is the ignition, pin 2 is the fuel injection.
see Engine and OBD Diagnostic Codes
I'd probably get a 'noid light' and plug it into one of the main injectors, and crank it, and make sure its just blinking and not steady on and flooding. all 4 injectors are wired together and fire together, so you only need to test one.
this is a 1991? there's no codes on pin 2 or pin 6 of the diagnostic block? pin 6 is the ignition, pin 2 is the fuel injection.
see Engine and OBD Diagnostic Codes
In the meantime I'm replacing the high pressure fuel pump. Does anybody know where to get adapters/terminals to convert the screw type terminal connector ends back to the original Bosch push on type?
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Put the noid light on it, flashes nicely with no continuous on state. Pulled the fuel pumps and tested them both outside and inside the car, plenty of fuel flow. Don't have a fuel pressure gauge but the quantity of fuel appears adequate. After I reassembled the fuel system today I tried to start it and it coughed and stumbled before dying again. Tried cranking it a few more times then pulled the No. 1 plug and it was wet with fuel. Ignition stage next? What heat sink compound should I use on the ignition stage? The same stuff as is used on computer CPU's?
Last edited by revolvus; Sep 8, 2019 at 03:32 PM.
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so now you're saying there is no spark at all? or not on some cylinders? if you are now thinking to check the power stage
strongly suggest reading the writeup in post #19. as we all have found out sometimes a part that appears dead is
not...
strongly suggest reading the writeup in post #19. as we all have found out sometimes a part that appears dead is
not...
Last edited by silvermine; Sep 9, 2019 at 08:08 AM.
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No, it has spark. It was suggested above that I check the power stage and I've read in other places on the net that they can be quirky. They aren't expensive so I thought to give it a try. Since changing the ECU I don't have any codes for the fuel injection or ignition. It did cough and hit on a few cylinders after I reassembled the fuel line and pumps.
I've also read that computer type heat sink compound works, does anybody have any info?
I've also read that computer type heat sink compound works, does anybody have any info?
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From: FL
No, it has spark. It was suggested above that I check the power stage and I've read in other places on the net that they can be quirky. They aren't expensive so I thought to give it a try. Since changing the ECU I don't have any codes for the fuel injection or ignition. It did cough and hit on a few cylinders after I reassembled the fuel line and pumps.
I've also read that computer type heat sink compound works, does anybody have any info?
I've also read that computer type heat sink compound works, does anybody have any info?
no mo volvo
Joined: Oct 2010
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From: 37 North on the left coast
any time you remove the power module, you should clean the back side of it, and the surface its mounted on, and spread a THIN layer of heat sink compound on the back of the power module before reinstalling. As far as I can remember, this is the only place its used on 240/740/940's... you only use a little dab, spread evenly with something like a credit card.
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Yes, I pulled the cable and used electrical contact cleaner, no improvement. I believe that there's a test procedure, anybody have a direct reference?
no mo volvo
Joined: Oct 2010
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From: 37 North on the left coast
if you have strong spark, then the ignition power module is working fine.
if you have fuel (wet plugs) and spark, then all thats left is timing. maybe the spark plugs are connected in the wrong order. maybe the timing belt is way off.
if you have fuel (wet plugs) and spark, then all thats left is timing. maybe the spark plugs are connected in the wrong order. maybe the timing belt is way off.
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I keep wondering about timing too. I'm going to pull all of the plugs and the distributor cap and put my inspection camera in the sparkplug holes and make sure that the mechanics are in sync. This is driving me nuts.
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