Low rpm (1000-3000) hesitation?

douglas vincent · Post by **douglas vincent** » Thu Mar 09, 2006 8:29 am

OK, I think I have decided that I ALWAYS have misfire/hesitation below 3000 rpm, its just that it is SO BARELY NOTICABLE off boost that I just finally decided that I have it off boost. It is just that when on boost, it becomes hugely noticable.

So...what could cause misfire below 3000 rpm?

I have new plugs and wires. Thats it. This leaves open EVERTHING else.

I do have a cracked knock sensor.?!?!

I have done a grounding mod.

MAF is clean (at least I think)

Battery is ? It starts and runs great, but I have killed it dead ALOT.

napphappy · Post by **napphappy** » Thu Mar 09, 2006 9:55 am

replace the cracked one with an updated knock-sensor and try a different coil.

NICO · Post by **NICO** » Thu Mar 09, 2006 10:50 am

i dont no but my regular ej22t motor all ways did it and the new ej22t with dohc dont do it. something in the heads i think.

vrg3 · Post by **vrg3** » Thu Mar 09, 2006 3:57 pm

What's your current fueling setup? Still using injectors bigger than stock with fuel pressure higher than stock with the JECS MAF sensor? Couldn't this just be due to it being all "wrong?"

Post by **Legacy777** » Thu Mar 09, 2006 7:29 pm

vrg3 wrote:What's your current fueling setup? Still using injectors bigger than stock with fuel pressure higher than stock with the JECS MAF sensor? Couldn't this just be due to it being all "wrong?"

I'm going to really have to agree with Vikash.

Your fueling setup is sort of pieced together. It works...for the most part, but is not the way it should be done.

douglas vincent · Post by **douglas vincent** » Thu Mar 09, 2006 8:04 pm

Well, it could be.

But.

My fuel pressure is back to stock, and I passed emmissions which means I am running fuel somewhat correct.

Anyway, Kelley is loaning me a black knock sensor for testing.

vrg3 · Post by **vrg3** » Thu Mar 09, 2006 8:40 pm

But what is your fueling setup?

douglas vincent · Post by **douglas vincent** » Fri Mar 10, 2006 12:06 am

370 cc injectors (instead of 270 cc)

Jecs MAF instead of aluminum maf.

Got another theory since it turns out it was my old knock sensor was cracked, not this current one.

New theory.

Too much gas. Engine gets too much gas and cant burn it all at low rpm. Higher rpms of course would be able to eat more fuel.

So....I am going to pull alot of fuel down low at WOT and see what happens.

Subtle · Post by **Subtle** » Fri Mar 10, 2006 7:23 am

Had that problem. The misfire was at its worst 2500 to 3000, at part throttle and going up a long but not too steep grade.

Also the colder the temp the worse it got.

Pig rich is what it was and with the mods it was time to step up to a stand alone ECU.

No probs since

douglas vincent · Post by **douglas vincent** » Fri Mar 10, 2006 7:32 am

Killed the loptop tonight. Don't know what happened, but.... Its 100% dead. Need a new one fairly soon.

douglas vincent · Post by **douglas vincent** » Sat Mar 11, 2006 4:25 am

Well, for the 5 minutes the laptop started working again (keyboard is farked!), I was able to pull some fuel down low at WOT. Off boost, it runs better. On boost, maybe. I didnt pull that much fuel, and didnt get into the rpm ranges that I wanted before the laptop went on the fritz.

But, I think I am on the right track.

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Low rpm (1000-3000) hesitation?

Low rpm (1000-3000) hesitation?