Thread: erratic running L67

passenger to driver in the rear 2--4--6
passenger to driver in the front 1--3--5

surging idle is usually a vac leak

yeah my guess too is a vac leak. one trick to find the leak is to spray starting fluid around the engine and hoses if you hear the rpms change in response to the spray then you found the location of the leak. could be a hose or gasket.

ok. so i didn't plug the hole under teh throttle body for the evap or egr..., made a block off plate and now its MUCH better but still a little surging at idle (it's in a jeep rock crawler so no emissions). my buddy thinks it's runnign a little rich, but no visible black smoke.

i took it for a test drive and it had ZERO power, just barely enough to get it around the block...i'm kind of leaking towards possible vaccum leak still, maybe somewhere else. the supercharger is making some odd noise, like possibly a bad bearing....the old screwdriver to the ear trick says it is coming from the nose cone, there is a brand spankin new nose cone at the local pick n pull, not sure if it's ok to just grab one and interchange it like that?

still not throwing any codes...


FML =)

Originally Posted by balterbuilt

the supercharger is making some odd noise, like possibly a bad bearing....the old screwdriver to the ear trick says it is coming from the nose cone, there is a brand spankin new nose cone at the local pick n pull, not sure if it's ok to just grab one and interchange it like that?

It's your coupler just order a new one and you'll be good to go.

ok, so i found a small vacuum leak and got it fixed, it was my fault anyways but no more surging.

the major problem is that there is still NO power, like barely breaks 20 mph. it feels like the motor is in limp mode. at idle in park the motor will rev quick and smooth like it should, but as soon as you put it in gear and there is a load on the motor you get nada. I need to get this motor going asap for a big wheelin trip on memorial weekend!!!!

i also had to take apart the throttle pivot to make a custom linkage. is there any way i could have put this back together wrong and even though i am able to attain full throw of the throttle, maybe im not engaging something that would cause the motor to not be getting full throttle?

How did you tune it? Is it set correct for the trany you are running ?

I'd want to know what pcm/harness was teh basis. Kinda sounds like some form of knock or torque management is pulling all the timing.

Did you put them in..or touch them? If not, then no. If you touched them. then take them back out and torque to only 14ft lbs. the torque effects the sensitivity.

I case/crank learn might be in order. What octane fuel are you running?

Most octane boosters raise the raiting by .1, meaning if you had 87 octane, it would raise it to maybe 87.1 or 87.2.

The fuel could be doing it. I'd say get some xylene or tolulene from a paint store and toss that in.. see if that clears the problem. If so..it's fuel.

There's some formulas out on the internet about how much to add. I think a gallon would really up your octane on that 5 gallons. But best to check. I'm not an expert on that stuff.

The crank relearn is never a bad thing. It optimizes the pcm knowing where the crank position is.