1993 940 stalls after 5 minutes

940anders · Post by **940anders** » 19 Jun 2010, 11:21

I have a 1993 940 station wagon with 150,000 miles on it. It has started stalling after about 5 minutes of freeway driving. It starts again after a couple of minutes, and then it is fine. I have checked the fault codes, no codes showing. I have replaced the ignition module, ignition relay, mass airflow sensor, fuel pump relay and the crank speed sensor. Any ideas? What happens in the engine after about 5 minutes of freeway driving that would make this happen. The car also dies frequently directly after starting when the engine is hot. But since I replaced the ignition module it starts right away.

Post by **billofdurham** » 20 Jun 2010, 12:27

You have replaced several very expensive units but have you checked the basics like distributor cap, distributor arm, plug leads and plugs?

Bill.

940anders · Post by **940anders** » 20 Jun 2010, 20:40

Yes, I did sparkplugs, sparkplug cables, distributor cap and rotor. Thanks for the reply, any and all suggestions are welcome.

Retired MVS Contributor · Post by **Retired MVS Contributor** » 21 Jun 2010, 06:35

Check the thermal switch for the cold start injector located in the engine block...If this switch does not disconnect the cold start injector when the engine is hot, flooding will occur when starting a hot engine...To check it out simply disconnect it for awhile and see what happens...This injector only needs to work when the engine is cold...

gyrene · Post by **gyrene** » 21 Jun 2010, 18:36

Where is the cold start injector located? Do you have a picture of it?

Retired MVS Contributor · Post by **Retired MVS Contributor** » 21 Jun 2010, 20:04

The cold start injector injects directly into the intake manifold and is underneath it...As I understand it after reading today, with your model, there is no thermal switch... It is controlled by the ECU...I don't have a picture, nor a way to upload one if I did...

gyrene · Post by **gyrene** » 22 Jun 2010, 05:40

thanks jerrymcc.

Post by **billofdurham** » 22 Jun 2010, 12:23

If you go to this topic you will find 2 pictures of the cold start injector. They aren't much to look at but they will give you some idea of where to look and what to look for.

Bill.

940anders · Post by **940anders** » 07 Aug 2010, 12:12

I finally took the car to a third mechanic. Told him everything that had already been done to solve the problem, and left the car with him. He called me back an hour later and told me that the fuel pump relay, which another mechanic had been paid to change in 2009, was dated 1992. I had been ripped off. It's sad when this happens. This was one of the first things that I wanted to fix. So he put in a new fuel pump relay and the problem was solved. If this had been done a year ago, it would have saved me several extra repairs and a lot of money. Not to mention the car stalling on the freeway in LA, which was very scary. Now the car runs great, and I'm figuring out what to do with the guy who ripped me off. I have the receipt that claims that he exchanged the fuel pump relay. And I have the faulty relay dated 1992.
Thanks for all support and help.

Post by **billofdurham** » 07 Aug 2010, 15:40

Thank you for the update.

Bill.