1991 SSE rough engine running

[derkroenung]

Moin, Moin,
I bought my Bonnie a couple of days ago, since Friday licenced.
I brought it to my home over 300km without any problems.
Now the engine starts running rough.

No matter if the engine idle or if I thrust.
It sounds exsactly like one cylinder is not working...
I checked the sparks and wire, they are looking old but they work. ( will order new one )
I tried by pulling of the spark plugs: every cylinder works.
I did not pull out the injectors, but I felt that they were beating. There is no error indication.
I do not have full power, but i can drive. still it just sound like one cylinder is not working, even at 3000rpm.
I only start running rough if the engine is warm.

Any Idea?
I suspect the fuel pump and injectors. But I have to admit that I am not familiar with electronic injections. I much prefer mechanical ones.

Regards Mike

[derkroenung]

Car is still not running.
But I have more information. Maybe somebody have an idea how to figure out the problem.

- cold start: engine runs normal
- engine warm: engine runs on 5 cylinders
- I have spark, but injector is not running.

How can I locate the problem? Is there something I can check by myself? (I have multimeter)
I have to Identify if it is in plugs and wiering, or in the ecu

[95naSTA]

You can test at the injector plug with a #194 light bulb and see if it flashes.

[derkroenung]

Hello,
thanks for your answer. It inderectly helped me finding the weak point.
I have no idea what a #194 light bulb is. We are not using this code for our bulbs.
So I got something what looked similar to that what I saw in google.
It didn' work.

BUT: Because of the try to get it flashing, I found a broken solder joint
Engine runs! Hope it was the last engine Problem


Sorry for the late answer. This ski-season was so much work. My shop eats all my attention.
But now I'm free to take some time with my Pontiac

[95naSTA]

Nice!

For what it's worth, heres a pic of the bulb:


More or less a small 12v bulb with contacts you can bend out and fir into the injector clip.

[derkroenung]

Hello,
yeah, I only got a 5w, not a 3.8w. We call them W5W
Maybe the the electrical resistance is too high at 5W

Anyways engine runs