I have a 1990 240 Wagon with over 200K miles on it. Recently, when it was driven on a long trip, the engine started surging and then died completely. We tried to start it - and after a couple of tries - it started again, but continued to surge. Then after a couple of miles it died again. We let it sit for about an hour and it started right up.

This happened once before, so we have replaced the following. The Fuel Pump Relay, O2 sensor, intake manifold gasket, spark plug wires, and flame trap. The car has codes of 232 and 113, which from my reading is the fuel is too rich.

In doing a search for these codes, it would lead me to a vacuum leak. However, that does not seem to explain why the car dies. I have not replaced the fuel filter, but was planning to do this on the weekend.

Does anyone else have ideas of what to check? I will check the vacuum, but again, that does not seem to explain why it dies.

Thanks for the help.

Rodney

 

The two items to check at the top of my list are air mass meter and fuel pressure regulator.

 

Thanks for the reply. What is the best way to checkthe MAF meter? Do I just hook up a volt meter to the proper terminals and check out the resistance or voltage that is measured as the flap opens and closes? If so, what should my readings be? How about the Fuel Pressure Regulator? Is there a way to test this - or is it better just to replace it?

I have also seen a post about another relay that could cause problems – called the radio suppression relay. Not sure what this relay does – but it seems to come up when this type of problem is described. Could this also be a problem?

 

Depends. The '90 240 could have LH-2.4 or LH-3.1 and the AMMs are different. If your's is 2.4 (platinum wire) the resistance should be 2.5-4.0 ohms according to Bosch. That's between terminals 2 and 3 of the AMM with it disconnected.

The heated film AMM (LH-3.1) should have a resistance of 108 ohms between terminals 1 and 4.

But I think you're on the right track with the vacuum leak. I mentioned AMM because I'm thinking air leak, like there's air getting sucked it that's not being measured by the AMM. Or the AMM is faulty. Check the bellows tube from the AMM to the throttle body. Also possibly leaking intake manifold gasket or throttle body gasket.

The fuel pressure regulator is a common failure. The diaphram breaks and allows fuel into the vacuum line. Best way to check is to pull the vacuum line (the skinny one) and sniff for fuel. There shouldn't be any. Sometimes it's obvious, like you pull the vacuum line and fuel leaks out.

Not sure what you mean by the flapper in the AMM. Were you thinking of the idle air control motor? It wouldn't hurt to clean out the IAC and check the hoses. A bad IAC could give terrible idle surge.