poor low rpm performance on 92 EJ22

[jelly man]

I have a 92 EJ22 in my 85 wagon. It ran fine after the swap for about a year then it started running weak at low rpm. Under about 2500 rpm it barely accelerates, then when it passes a certain rpm (about 2500 my tach isn't hooked up) the engine kicks in and runs normal. This behavior is independent of throttle setting, engine temperature or vehicle speed. I've replaced the coolant temperature sensor, maf sensor, O2 sensor and checked the tps(it's ok). It's runs rich at low rpm evidently. It started a couple months before my emissions test. It fouled out plugs and wiped out the O2 sensor (all were covered with black soot. It was running way rich at both low and high rpm. When I replaced the O2 sensor the high rpm passed but the low rpm was still rich-about 3 times the maximum allowable HC and CO limits. The new cat brought low speed emissions into compliance also but if I keep running it I'll wipe out the O2 sensor and the cat again. The computer isn't setting any codes. I'm stumped - any ideas?

Edited September 17, 2008 by jelly man

[idosubaru]

how many miles/what's the history of the motor?

 

the low power would lead me to think the fuel isn't getting burnt properly verses too much fuel getting dumped in.

 

ignitor? or the ignitor...i forget what it's called, but there's another ignition related component that's close to the windshield on an EJ22 (not sure where you put it)?

 

i doubt the fuel injectors are to blame, i think you'd just have bad gas mileage, not poor running - but -

 

fuel injectors sticking? try some fuel injector cleaner, make sure they're firing/opening properly.

 

you can have them sent off and reconditioned/rebuilt by a company like RC Engineering (that's who i use). they are expensive, there's cheaper ones out there i just like those guys. and they send a report back indicating the condition of the injectors when they receive them. when i send a batch in there's typically one or more listed as "dripping". maybe you have a "dripping" or leaky injector?

[Spiffy]

does it stumble, or just bog and slow to get up there?

 

 

 

--Spiffy

[jelly man]

It doesn't miss if that's what you mean. It just acts as if it has little if any power - even less that the original EA82 that was in it. The transition is very clear though. Once it hits a certain rpm it just takes off.