1992 940 Turbo Not Starting!!

940in808 · Post by **940in808** » 02 May 2011, 10:01

I have seen many posts regarding "Non Starting" issues and I have pretty much tried everything. I know I'm getting close cause there is not much more things I can do as far as troubleshoot.

Things I have tried:
-Checked fuses in middle compartment.
-Checked and replaced fuel pump relay in middle compartment behind the fuses.
-Checked and replaced the "Radio Suppression Relay" located on the driver side strut panel.
-Checked the "MASS AIRFLOW SENSOR". I unhooked the electrical connection and the car started once. Would not start again even with the electrical connection unplugged.

Things I have not tired:
-Check air filter
-Change MASS AIRFLOW SENSOR
-Test fuel pressure (I read in some posts about testing residual fuel pressure by releasing some fuel from the Schrader valve,
I have no idea where this is located or what it looks like nor how to relieve the fuel from it once I find it)
-Test fuel pumps - I'm supposed to hear some kind of buzzing sound? Honestly I never heard this sound from any car I have ever driven. It will be interesting to try and listen for something I have never heard...lol

I have a appointment at my local garage tomorrow but prefer to DIY and save some $$....but if I can't fix it today I may have to bite the bullet and take it in.

Any other suggestions and advice is greatly appreciated. Thank you in advance

Post by **billofdurham** » 02 May 2011, 11:31

Welcome to Matthew's Volvo Site.

Have you checked for fault codes using the On-Board Diagnostic (OBD) unit? Instructions for its use are pinned at the top of this forum.

Listening for the fuel pumps is one way to find out if they are working. On the 940 you have two, one in-tank which acts as a priming pump and the main mounted under the car. When you switch on the ignition you should hear them momentarily if they are working. The main pump can be heard from the driver's seat if you leave the door open. The in-tank is more difficult to hear but the easy way is to remove the filler cap, have someone switch on the ignition whilst you listen at the filler.

A quick check that the relay is working is to put your finger on top of it and switch on the ignition. You should feel a click as the first part of the relay activates. If the relay is working and you can hear the pumps you should have fuel to the engine.

A quick check to see if you have fuel reaching the engine is to crank it then pull out one of the plugs. If fuel is present you will be able to smell it and the plug tip should be wet.

Attached is the fuel pressure pipes for your car showing the pressure regulator, part #5 and the Schrader valve, part #1b.

940 fuel pressure pipes..pdf: (52.75 KiB) Downloaded 427 times

Bill.

940in808 · Post by **940in808** » 02 May 2011, 11:49

Thanks Bill for the quick reply. I have verified that the relay is in fact engaging because as you stated I was able to feel it clicking as I turned on the ignition. I'm leaning towards the fuel pumps as being the culprit however more detective work is needed to solve this crime of not starting. I'm going to the slavageyard today after work and get me a MAF to rule that out. Do you think perhaps the air filter might be the problem? I will test today after work. Thanks for the PDF it will certainly help in my quest for justice and a working car.

-Brandon

940in808 · Post by **940in808** » 02 May 2011, 11:54

Btw I haven't tried the On-Board Diagnostic (OBD). To be honest I'm more shoot first ask question later, but I'll give it a try and see what I come up with. Ty

940in808 · Post by **940in808** » 04 May 2011, 00:02

Just got my car back from the local hackcanic. Bill came out to $200 and he didn't do squat and told me I had a bad fuel pump in the gas tank. Im about 99% sure he's correct considering I covered everything else. Im not sure how he tested it considering he never took a look at the pump to test if it was/was not working. I guess he's clairvoyant, in any case I'm on a mission to change the rear fuel pump myself. Does any one have a video or step-by-step instructions? Thank you in advance and I appreciate all the people sharing their experiences and knowledge.

BTW I did check the OBD and all i got was a 1-1-1

Post by **billofdurham** » 04 May 2011, 11:28

It is a fairly straightforward job as those nice people at Volvo put an access hole in the floor of the luggage compartment for you.

The attached shows how to do it. It does say to drain all the fuel but if it is reasonably low you should be OK. No naked lights while you are doing this.

940 Fuel tank unit replacement.pdf: (1.3 MiB) Downloaded 347 times

Bill.

940in808 · Post by **940in808** » 05 May 2011, 14:06

Aloha All,

Thanks for the info, it gave me the confidence to tackle this issue by myself. I could not see spending close to $1K on this repair. I got the pump installed and car started first try no issues...except now the gas gauge stopped working and the low fuel light stays lit. Guess I'm going back into the trenches.

940in808 · Post by **940in808** » 16 May 2011, 22:53

Here is the latest on my 940. Plain and simple its not working. It cranks and I can hear the fuel pumps but it will not start. I replaced both fuel pumps and added new filters. I bought a brand new OEM radio suppression relay from Volvo, fuses are okay, fuel ignition relay I can feel it clicking. Not sure what to try next...any suggestions?

940in808 · Post by **940in808** » 19 May 2011, 16:44

I read online someone mentioned to try and replacing the Crank Sensor. I bought a OEM sensor from Volvo but I have no idea where it goes. Does any one have a picture of where this goes on a 92 940? Thanks in advance.

940in808 · Post by **940in808** » 19 May 2011, 21:36

Im happy to report I have SUCCEEDED in getting my 92 940 turbo working. This is a glorious day! Come to find out it was the Crank Sensor. Amazing how something so simple in design can be the Achilles Heel. For those people who are having a difficult time in locating the crank sensor (As I did) its located right below the distributor on the back of the engine. The way I found it was by looking for the same type of connector that I had on my new sensor and then following the line. I couldn't find any diagrams or pictures on the net and will try and take some pictures for future reference for others.