T O P

Replaced plugs, wires and cap and still have a pretty bad stutter and jerky around 3k rpms. New air filter and made sure all that was clamped down well too. Any ideas? Not throwing any engine codes.

Replaced plugs, wires and cap and still have a pretty bad stutter and jerky around 3k rpms. New air filter and made sure all that was clamped down well too. Any ideas? Not throwing any engine codes.

1839MarinerBlue

Could definitely be fuel stuff. Start with a fuel filter and check for discoloration & rust in the fuel. The fuel tanks in these old cars are all getting rusty from the inside out.


apocryphie

I'll definitely check that! Sounds like a pain in the ass to check though!


shiverdc2002

Distributor timing is good?


apocryphie

I can only assume everything is factory stock on it. I've only driven it a handful of times since buying it so I dont know much


shiverdc2002

Check your ignition timing. That could be contributing.


apocryphie

I'll check that! It came with a repair manual so I'm sure I can figure it out


SteveFrench7678

I don’t know how to fix it if it’s wrong, but it might be the distributor wires going to the wrong cylinders. Also that repair manual is a GOD SENT.


apocryphie

Guess I'm lucky it came with the repair manual! I'm very certain that the wires are in the right order since I did those myself. Plus I feel like it would be a lot more pronounced if that was the case. It would be a constant misfire, whereas this only happens around 3k rpms and only in gear not in neutral


MR2Rick

I am not sure what is causing the problem, but here is what I would check: 1. TVIS not opening 2. Vacuum leak 3. intake air leak upstream of MAP/MAF sensor 4. throttle position sensor


apocryphie

I'm confident I can rule out an air leak! I went through that whole system thoroughly today. But I'll check the rest, thank you!


pancakes8u

I would check out a new MAF sensor, I had a similar issue in my spyder where it would stutter and feel like it had no power over 5k rpms. New MAF and she was right as rain.


apocryphie

I'll try that!


stopdefaultreddits

I double a check on the tps


Slylizardcue

Tps reports. Every time.


skottpockets

Check vacuum lines, if they're original, they're most likely brittle and have started developing cracks. Even on a really well preserved example as yours seems to be.


xamsiem

I would just say, go ahead and replace all vac lines super easy. Just msg me for info.


apocryphie

Thanks!


FatEgrosOnly

I had the same problem, check your ignition timing, and use a very generous amount of carb cleaner on your throttle body. Mine was coated in gunk. Also check for water under the spark plug wires.


apocryphie

I'd did have water in the spark plug wires when I first got it, but replacing the wires with ngk fixed that! They get a good seal now


pjs1975

Find another MR2 owner near you and swap parts until it's fixed ;) I guess the ignition coil could be to blame, but I wouldn't start there. I kind of think it's not fuel related because it's at one area of the RPM band. It doesn't jerk and stutter at high RPM or anything? You said you changed plugs/wires/cap. How'd the rotor look? Was it in good shape for sure? If not, wouldn't hurt to take a look and clean off any buildup. Someone else said check your timing, that's not a bad place to start.


apocryphie

Lol it was hard enough finding this mr2, much less finding another one that someone would willingly swap parts! It does jerk a little at higher rpms but significantly less than at around the 3k range. Frankly I only got the car up around 4k a couple of times, never higher than that. Rotor looked to be in pretty good shape, no buildup or residue or anything. I considered swapping it out regardless but it's apparently a massive pita from what I've seen and I'd rather narrow it down before throwing parts at it.


pjs1975

Good call on not replacing the rotor, I just wanted to make sure it still looked good.


Lethalsavage117

Try changing oil viscosity, any exhaust leaks? TVIS not engaging? You should be able to get it to at least 6k rpm It does sound like a fuel injection issue also or maybe the heads are bad????


apocryphie

No exhaust leaks not sure if tvis is engaging I havent been able to check. I got it up to 7k just now and didnt feel a stutter after 5k. So its between like upper 2k and upper 4k that it stutters


ErickPlaystation

Have you tried cleaning the AFM? I had issues with my AFM, ran fine after I replaced it.