Severe acceleration issues.

[d.rising86]

I have a 1993 Lincoln Mark 8, and I have been getting some acceleration issues that have been getting progressively worse. It started a month or two ago, with a slight hesitation when trying to accelerate. It stayed that way for a few weeks then one day after starting my car and pulling away from my house, the RPM's completely dropped and my engine completely stopped accelerating. It didn't die, though the battery light did flash on for a second, but it would not accelerate for a few seconds. After those few seconds, the RPM's kicked back up and the car drove fine, aside from the stuttered acceleration. This went on anytime I started my car whether hot or cold and it only happened within the first few minutes of me starting the car and driving. Now, just recently, my acceleration has become extremely stuttered and sometimes it will drive like i'm running out of gas, with my RPM's barely reaching 3k. I've replaced the spark plugs and wires, checked my battery and alternator, replaced both the fuel pump and fuel filter, replaced the Cam Position Sensor, and sprayed some TB cleaner into the TB. Any ideas as to where I should check next?

 

[Right on the Mark]

I have a 1993 Lincoln Mark 8, and I have been getting some acceleration issues that have been getting progressively worse. It started a month or two ago, with a slight hesitation when trying to accelerate. It stayed that way for a few weeks then one day after starting my car and pulling away from my house, the RPM's completely dropped and my engine completely stopped accelerating. It didn't die, though the battery light did flash on for a second, but it would not accelerate for a few seconds. After those few seconds, the RPM's kicked back up and the car drove fine, aside from the stuttered acceleration. This went on anytime I started my car whether hot or cold and it only happened within the first few minutes of me starting the car and driving. Now, just recently, my acceleration has become extremely stuttered and sometimes it will drive like i'm running out of gas, with my RPM's barely reaching 3k. I've replaced the spark plugs and wires, checked my battery and alternator, replaced both the fuel pump and fuel filter, replaced the Cam Position Sensor, and sprayed some TB cleaner into the TB. Any ideas as to where I should check next?

Is it doing it ONLY after a total stone cold start? My 1993 cannot go WOT right after cold start. It will drive normal with like 50% throttle but if you WOT it, it will fall on its face like a rev limiter is being put on. No problems with car at all.

 

[d.rising86]

Nope. It doesn't matter if it's hot or cold. I could be doing 70 down the highway with my engine at it's normal running temp, and if I pull over, turn the car off, and start it back up it will do it within minutes. Completely drop the RPM's and cease acceleration for a few seconds. Then drive normally for the rest of the trip.

 

[SleeperMark]

I had a similar issue. Tracked it down to the TPS. Went through a few crappy duralast ones, then finally gave in and replaced with a motorcraft one and haven't had a problem since. That may not be your issue, but mine used to do the exact same thing. I would back out of a parking spot and when I went into drive and got to about 10mph it would fall flat on its face and then pick up again and be fine until I shut it off and restarted. Did it almost every time.

 

[chris2523]

Is it doing it ONLY after a total stone cold start? My 1993 cannot go WOT right after cold start. It will drive normal with like 50% throttle but if you WOT it, it will fall on its face like a rev limiter is being put on. No problems with car at all.

mine did this. O2s fixed for awhile, but its been coming back recently. guess it needs O2s again.

 

[LowLincoln]

My car, although ran well, out of nowhere the engine would either die or act like it was running out of gas / extreme lean condition. Turned out to be the PCM itself. It was totally random but did not do it much during long trips. It's one of those rare times that the PCM itself goes bad. Got a junkyard PCM from eBay, plugged it in and everything was perfect after that. Not a single occurrence since about December.

 

[d.rising86]

Thanks for the info, everyone. I will give these fixes a try and will post as soon as it's resolved.