Engine stutter/idles rough, also accelerates poorly

[eldusto84]

My Delorean is suddenly having a hard time idling smoothly. When I start the car up, the engine chugs in a very dramatic fashion, sometimes even stalls out. I've pumped the gas pedal to get the RPMs up, and that helps a bit, but there's a delay between me pumping the pedal to the engine actually responding. It continues to chug for a few minutes before things level out, but it almost feels like the car is running low on gas (even though I'm more than 1/2 a tank full). The chugging actually shakes the car when it first starts up.

Once I'm on the road, the car is hesitant to accelerate properly when I push the gas. It will take off slowly at first, then after a few seconds it will jump forward. 2nd gear is just as bad, but it's mostly fine by the time I'm in 3rd and above.

Any thoughts on this problem? I'm guessing it's something with the fuel system- pump, filter, distributor (ugh), but I don't know for sure. Is it simply the type of fuel I'm using?

[jawn101]

Does the problem go away after the engine warms up? Check for vacuum leaks at your WUR if so.

[82DMC12]

Did this just all of a sudden start happening ? If so, I would think the problem is electrical, possibly a loose plug wire.

[jawn101]

Did this just all of a sudden start happening ? If so, I would think the problem is electrical, possibly a loose plug wire.

That would be my second guess - I had a similar issue when my alternator decided to stop charging one day. The battery couldn't provide enough spark to keep things running smoothly.

But I had a very dramatic stuttering/sputtering/lack of responsiveness when cold when the vacuum tapping on the front of my WUR decided to poke a hole in one of my silicone vacuum lines. Trimming the line and reinstalling it (a free and 30 second job) fixed it instantly.

[mluder]

Does the car stay runnin - I assume so if the problem is a rough idle. You might check the fuel pump relay. Could be on its way out.

Also, check your injectors - make sure they are properly seated. I had two pop loose on me out of the blue and the car would barely start and idles rough because two of the cylindars were getting no fuel.

Cheers.
Steve

[82DMC12]

That would be my second guess - I had a similar issue when my alternator decided to stop charging one day. The battery couldn't provide enough spark to keep things running smoothly.

But I had a very dramatic stuttering/sputtering/lack of responsiveness when cold when the vacuum tapping on the front of my WUR decided to poke a hole in one of my silicone vacuum lines. Trimming the line and reinstalling it (a free and 30 second job) fixed it instantly.

Yes, I've seen a WUR with a blocked fuel screen give terrible drivability when the engine is stone cold. That particular issue didn't affect idle however. The drivability would improve to nearly normal once the engine was warm. It was easy to diagnose with a fuel pressure gauge.

Andy

[jawn101]

Yeah, I don't think the leak at the WUR affected my idle either. But his other drivability symptoms (lack of responsiveness from a stop, etc) are spot on what I was experiencing. There could easily be multiple issues - it's a DeLorean after all :)

Or it could be entirely unrelated! :) I just remember how pleased I was to fix my stumbling issue for free.

[eldusto84]

Found the problem. It was a loose wire connection on the ignition coil. Just popped it back on correctly and the car runs smooth again! Phew. Thanks for all of your suggestions!

[Jonathan]

Found the problem. It was a loose wire connection on the ignition coil. Just popped it back on correctly and the car runs smooth again! Phew. Thanks for all of your suggestions!

Hey, cool! Glad you found the problem. The other thing that came to mind from your description of the problem could have been related to getting the plugs wet after a car wash or something. If you get the power washer going over the car a bit too aggresively and soak down the engine bay by accident, this type of thing can result. Happy driving!!

[jawn101]

Nice! Congrats on finding it. Don't you love when the fixes are free? It's rare so enjoy it extra. :)