Did some brake work on my stock 85 GSL-SE, turns out I didn't get it warmed up enough before I parked it.

Once I got it started it was running horrible - rough idle at 400 rpm - running on one rotor at times, with random surges to 2000 for 10 to 30 seconds. Won't rev past 3500 RPM on the street. Puffs black out of the exhaust

Once I shut it down it floods itself out again. I've got strong compression, spark, and the fuel pump is at least running, but all signs point to a fuel delivery issue to me.

Anybody seen this before - ideas where to start?

 

actually checked compression?

 

Tested by ear anyway, don't have easy access to a gauge.

 

Now that I think about it, I probably killed the oxygen sensor.

 

Badly leaking injectors my guess
any fuel in oil?

there is procedure in FSM to check the injectors

also I'd change them spark plugs and see if any difference

 

Wasn't the O2 sensor. Intake Air Temp and Coolant Temp test relatively close to specs. The oil was really gassy when I changed it out. Ill check out fuel pressure and try to find that injector test next.

 

when you had it running how long did you run it for? if it wasent long go for a run down the highway. get those plugs nice and hot.

 

When I can get it started I'll go for 10 minutes or so in the city. Plenty long enough to get it warmed up. No highway though - 75mph falls right in the rpm range where it doesn't want to run.

 

Turns out I lent my fuel pressure test kit to a friend and never got it back...

But anyway, fuel flow looks okay, about 1/4 gallon in 30 seconds. There was plenty of residual pressure in the lines after sitting for 30 minutes, so it might be safe to assume the injectors aren't leaking.

The problem seems to be shifting on me. Still hard to start, 400 rpm idle or lower. Still running pig rich. However once it warms up its acting like a vacuum leak - idle jumps up and bounces between 1500 and 2000 with the clutch out, idles steady at 2000 with the clutch in. Could a stuck ACV/BCV do that?

 

PROBLEM SOLVED!

Turns out I the fusible link to the ECU was broken. I must have bumped it when I was moving the hardline for the left front brake around. I'm amazed it ran at all actually - about time I replaced them with Bussman FLFs.

Thanks to those that provided suggestions, I'll pass the karma along.

 

I have a very similar / same problem. Car runs fine when cold, but after 5 mins of running it will not go above ~3K rpms. You described the fusible links. Are you talking about the link fuses next to the battery?

 

Those are the 5 Fusible Links on an -SE (12a cars only have 3 located there). You can check them for resistance, but realize that they may test okay, but not carry enough current. The 'Bussman' fix which people talk about is simply a plastic boxed fusible link which is designed to perform the same function and still fits into the spade connectors on our cars with no modification. Might be a good idea to swap those out for new Bussman fusible links, as they do get old and can fight corrosion. Good luck,