The Volvo is not starting again. I just finished a Timing belt/water pump to fix a leaky water seal and an old fraying belt. I also replaced the seals.

Went ahead an changed the rotor, cap, plugs and cords with bougis, Bosch Plugs and distributor. There was a sale at the local APS, threw an ignition coil in also since my original one tested slightly out of the range in my Bently Manual. still no spark at the plugs.

I am trying to preform the tests outlined in the Bently manual to check the ignition system. Please help me with this step.
Its Page 280-8 in my book, step number 3. check for power and ground at the control unit. While back probing the Control unit harness connector, check for continuity between terminal 10 and ground. switch the ignition on and check for positive battery voltage between terminal 2 and ground. Fig. 14 identifies the connector terminals. if any faults are found check the wiring to the connector.

Please someone with a bently manual, who has also possibly done this test help me out. I have tried back probing the terminal connector Fig. 14 is a Picture of the Ignition control Unit, with an insert of the Connector Terminal Identification. What is the correct method for back probing? stick my probe through the wire insulation? that doesnt seem right... in between the insulation and the plastic connector? Tried that, cant seem to make it fit..

Things i have already replaced/ checked.

Engine wiring harness, completely swapped out.
Engine mounts.
Engine flame trap.
Fuel 25 amp fuse near headlight relay.
Fuses checked and replaced.
Fuel relay in passenger Kick space.
New Spark Plugs, Wires, distributor, rotor, and ignition coil.


thanks

 

For a no spark condition, I would start at the source of the timing electrical signal - which for your model year is the hall sensor on the distributer. I am not familiar with the LH2.2 fuel injection (my cars have the LH2.4 which has the crank position sensor). However, there have been many write-ups here in the forum on how to troubleshoot issues with the hall sensor. Just do a search on hall sensor and you should be able to find some.

 

Thanks for the tip Act.

Im not sure but i thought people have told me that if is was the hall sensor that there would be no fuel, or spark. but im not 100% on that. Anyways, i went out and preformed the test outlined in the bently manual for the Hall sensor. Its step 6 on page 280-9. it goes like this... With the ignition off, disconnect the harness connector from the Distributor hall sender. Remove a spark plug, reconnect the plug and attach the plug to ground. Switch the ignition on, then briefly jumper terminals B & C in the connector. See fig 15. each time the jumper wire is connected, the plug should fire strong spark.

Note
This test simulates the Hall sending signal to the control unit. If the car does not start but the plug produces a good spark during the test, the hall sender is probably faulty and should be replaced.

So there you have it. Although earlier in the book the gently manual also says to preform tests in the sequence they outline. and i was asking about step three(3), you recommended i just to step Six (6). Well since i got a good spark but the car wouldnt start, and i happened to have a spare distributor sitting around.. i put it in. Now it will barely crank over. or crank a few times but then not be able to fully crank it all the way.


No one has ever used the bently manual to test the ignition system?

Maybe the spare distributor hall sender i had was also bad i guess. although this seems like something different. it will crank once or twice, want to go more but just doesnt seem to have the juice for it. if i turn key back to position two (2) and try to start again, cranks just fine, once or twice then does the same thing again. just had the battery charged up at the local APS. so i think that is good.

thanks

 

gotta be careful with that bentley book. it covers 20 years worth of the 240 and it sometimes confuses different generations

 

I thought the Bently manual was recommended from some posts i read here. but maybe not. the one i have is 83-93 volvo 240 DL, Gl, SE, and turbo. Definitely not trying to confuse anyone. Just trying to figure out how to diagnose this.

Hell, i barely understan most of the stuff in the bently book, or on this forum for that matter. Most of the technical jargon you throw out goes so far over my head, i dont even see it. I have never had any formal mechanical or electrical training. But i read about it enough times, then go try it on my volvo, i learn what they mean. I have only known this volvo 2 months and when i met her, she was dead and severely neglected. Just trying to save her from the pick and pull. maybe its not worth it. Aside from oil changes, and MTF changes in my old Honda, i have never done any "wrenching" in my life. never had to... the honda never had any issues, the battery, cold air intake and slotted brake rotors i put on just bolted right on.

Mostly i dont understand how Act came to the conclusion to test the Hall sender?

I assume there is a reason the Bently manual suggests to test things in a certain order? I would gladly accept any other test procedure or ideas.

If it was a faulty Hall sensor i would not have fuel on my plugs though right?

Just to make sure, i went out and checked that the Cam was in the up position at TDC, it looked possible that the intermediate gear was one or two teeth off, but i think that is just the angle i was looking at it, and made sure the distributor was pointing to the #1 cylinder.

The good news is that the water pump seals seem to be holding! So im pretty proud of myself. It reminded me of the first time I was party to a Abdominal Aortic Aneurism. Cleaning out all the old gasket material is just like pulling plaque out of dissected aorta.

Hope you all had a good weekend.

Thanks

 

well, the Bentley book is much better than any of the alternatives (Hayes is pretty bad and Chilton's isn't even worth using in the 'loo).

 

Im relieved...

It seems possible that you work in some field of electronics. From some of your installs and comments i can see you know how to trouble shoot and repair electrical problems.

Youre not familiar with the term Back-Probing, as a technical electronics repair term.. Haha at the hospital that means something quite different. How do i test for continuity on the multimeter? I guess i only know how to test volts and ohms.

Am i understanding bubbas comment correctly that if the timing was a few teeth off on one sprocket the car wouldn't start at all?


Guess maybe its time to take it to the Volkswagen guy down the street... Or the pick n Pull...


Thanks

 

if the timing belt is off, there's several possibilities. A) the camshaft is off one or more teeth in either direction, and/or B) the intermediate shaft is off one or more in either direction. some combinations will result in an engine that runs poorly, others in an engine that won't run at all.

as far as electrical continuity, thats just a special case of resistance (ohms), where continuity should be zero ohms (or very close to zero, even copper wire has SOME resistance to be precise about things), while an open circuit would be infinite. many digital multimeters have a beeper mode for this, where a very low resistance will beep.

 

ahhh, ok went and tested the continuity between terminal 10 and ground. Seems good. .03. also tested between terminal A and the corresponding wire that goes to the ICU, got no resistance. so the wiring does seem to be good.


That sounds like my issue, a few times it stared ran very poorly then died. If all the marks are lined up though, i ought to be ok it seems. Is it possibly turning the intermediate gear counterclockwise threw the timing way off? If so, how to get things to line up properly other than just lining up the marks? that i have done.

If the intermediate gear was rotated in the wrong direction, and that is causing early detonation, how would i be able to bring things back to 12*?

Thanks

 

By what method have you determined that you have no spark at the plugs?

 

Well, the only real method i know. I pulled the wire and put a known good plug on it, then had a friend turn the key for me. Nothing, nada. just cranked and cranked.

Could that happen from things bring grossly misaligned?

It seems like even if i line all the timing marks up again, it is still possible that a valve or piston will not be in the correct position?



I did see a spark when i jumped the Harness connector on the distributor/ hall sender.

I wish i had a bit more experience working on cars...

thanks

 

I'd probably try a test light connected between the control wire to the ignition coil (pin 1) and ground, that should blink with each ignition cycle when you crank the motor. if it doesn't, the problem is upstream from there (maybe the ICU/power module) if it does blink, then the problem is the coil or spark plug wires (including the primary HV wire from the coil to the distributor cap)..

 

Dont have a test light, I guess ill stop by the VW shop down the road and see how much they would charge to get things lined up properly again.


Thanks