I have a 92 RS with the 3.1 MFI engine. Lately it feels like I have no power.. Just today, some stupid Celica with a fart cannon was trying to play, so I downshifted and gunned it. But instead of taking off, it sputtered a bit and slowed way down, then started to CRAWL, sputtering as it went. It only happens when I mash the throttle. If I go easy on the gas, it doesnt seem to happen.

I did have a problem with a dead cylinder, but it was only a loose spark plug cap, and that problem was fixed. It feels like a dead cylinder, but when a cylinder goes out you can hear it just as much as you can feel it, and like I said before, it doesnt always do it.

Also, my car backfires like crazy above 4000 rpms. And only when I release the throttle. If I rev the motor to about 4500 and let off the gas, it sounds like a submachine gun firing off.

So, any ideas as to what my problem could be? For starters I will check my spark plugs, but they are hard to access, so I havent gotton around to it.

What else could my problem be?

 

it might be the ignition, i had the same problem and i ended up having a bad knock sensor and my ignitoin went a couple days later, check that

 

I had the same symptons in my old 83 Z28 back in the day...

It turned out, the magnetic pick up coil on the shaft of the distributor was shorting out to the shaft...

I believe this is the piece that the computer uses to determine timing.

We fixed the pickup coil and everything was back to normal...

Been awhile since then... but that is as much as i carn recall....

 

Answer above mine is 100% dead on.
Had my ignition module die at 75MPH.
Car backfired, too.
Weak igniton.
Pull distributor, rebuild it use all new parts under cap, then go to coil & replace that, too.
Plug wires, yep & plugs sure will assist in this mission.
Don't forget the timing chain mission eventually.
Really, backfire equals upburnt fuel due to poor ignition spark.
Lots of little things, but don't settle for just doing part of this igntion rebuild job.
Or else ya may be stranded.
Wanna walk in my shoes when the car dies!?!?
Atleast in SoCAl it's warm
Almost 90* TODAY!
Your broken car location may not be as pleasant, yes I was lucky.
Plan your budget for each project.
Distb rebuild it's some effort, timing chain replacment is major effort, plug wire & those things are "easy done" close hood mission.

 

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replace the coil and I bet your problem goes away. I had that happen a while ago. My alternator died and I had to tr and coax my baby home(about 22 miles) and it fried the coil. As long as i was careful and didn't get on the gas too hard, it'd drive ok, but as soon as it ran a little rich for more power...i got the shaft. Replaced the coil and all gone.

 

well, i was having issues with my car hesitating, sputtering under acceleration, and backfiring when you romped the gas from a stop (or put it more than half way down). My problems turned out to be a bad MAF (which you don't have) , a bad pick up coil, and a crapping out ignition module. Pick up coil was corroded, ignition module wasn't but the wire connections were (in the location where my MSD 6AL used to be installed. So, i'd say youre having issues with a pickup coil, or an ignition module, best of luck.

 

carbon clean that piece

 

I know this was posted 12 years ago. But how did your problem turn out. having same problem.