Engine trouble

Pritchard · 02-15-2001, 04:24 AM

I have a '74 2.0 L that is pretty much stock. I am experiencing a problem with the engine dying shortly after start up. Last nite I went out to start the car. It started right up and then died within 10 - 15 seconds. It did this many times. I eventually got the engine to keep running by feathering the throttle. Once warm, the engine ran perfectly.

Here's the situation. It rained steadily for three days and humidity was very high. My car is kept in the garage and has not been in the rain. I thought that I might have moisture in the dist. cap that evaporated as the engine warmed up. This morning it was raining lightly, but I drove the car anyway. The car started great and ran great for about ten minutes. Suddenly, the idle dropped to next to nothing. The engine stumbled at idle but ran OK above idle speed. When I parked at work, idle was still next to nothing (probably around 400 RPM).

Has anyone experienced this problem and found any remedies?

By the way, fuel pump comes on like it is supposed to, when starting, can't find any vacuum leaks, AAR closes as it heats up, and everything looked OK around the engine compartment.

Thanks in advance for your input.

David Pritchard

JmuRiz · JmuRiz's Garage

My car needs to be helped w/ the throttle when it's cold also. But then again I am running webber 40's...so I guess I have an excuse why it doesn't like the cold. I wouldn't think that FI cars would have this problem. Sorry I can't help more, good luck.

Nathan

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'73 2.0 914

SAWBA · 02-15-2001, 12:56 PM

I am by far an expert on this subject. I take my 914 to a garage. But, I have had several different instances like you desrcibed when I had my 1.7 FI.

The first was a head temperature sensor that needed replacement. But, this may have been for cold starting. Worth a check though.

Second, vacuum lines were bad.

Third, pressure regulator needed adjustment once, and a new one the second time.

Fourth, water somehow got into the control unit. The car ran good until it got hot, then wanted to die. So that was replaced too. Does black smoke come out the tailpipe?

My car even got to the point where it just flat out stalled and I had to wait for it to cool off. Even after cooling off it only lasted minutes.

This is a long shot, but does your battery have enough juice? I had an old battery had enough power to start the car, but didn't have enough to provide proper spark. At least that's what the mechanic told me.

Hope that helps. Sorry if it doesn't

JP Noonan · 02-15-2001, 02:35 PM

A friend's Nissan (has a Bosch FI similar to the L-Jet in the 928) had a similar problem. It was a MASSIVE vac leak. A 3/4" vac hose came off after the air meter so the car would only run if you cept your foot on the accel pedal. On the 1.8L look at the EGR to oil breather line. Block it off to see if there is a bad gasket in the case (oil filler O-ring) or if the EGR system is leaking. I agree that the CHT is suspect also.

BTW I've never actually owned a running L-Jet. So take the advice with a pound or two of salt.

MidMike · 02-15-2001, 10:33 PM

I think that your problem is vacume leak......The 10 to 15 sec running time is due to just the extra fuel injected by the cold starting valve........Once this fuel is used the car dies.......I had a similar problem with my 1.8........Found a 2 inch tear in my rubber intake elbow connecting the air flow meter to the throttle valve....I also replaced the the temp sensor and checked the Aux Air to see that it was closed when cold.

Pritchard · 02-16-2001, 04:10 AM

Thanks for all the feedback. The engine performed near perfectly on the drive home from work. I'll keep my fingers crossed that all will stay well with the engine.

I'm still thinking that moisture is the problem. As far as vacuum leaks are concerned, all lines are pretty new and have clamps to make sure that they seal properly. The CHT is new as well. The battery is just a few months old and charged occasionally when I don't get to drive the car as often as I'd like. Anyway, thanks for the input. You'd think that a 26 year old engine would know how to behave by now!

David Pritchard

JP Noonan · 02-16-2001, 08:53 AM

I don't know why I thought you had a 1.8L, but I re-read the post and now I'd suspect the ignition points, a vac leak to the MPS, and the manifold pressure sensor itself. In that order. I've had a problem like that (except for the temp changing it) and it turned out to be too small a points gap.