erratic running L67

**balterbuilt** · 05-15-2011

i have a 97 L67 that i just installed in my jeep. the motor is running extremely erratic. It wont idle at first, once you get it to warm up a second the rpm jump all over the place from a rough idle to about 2500rpms then back to a rough idle, over and over again. it is also running extremly rich. I replace teh TPS sensor, did not help, i haven't replaced any coil packs yet but they seem to get good spark. when i disconnect the cam sensor it runs much better but very lean, so i replaced that and it does the same thing when plugged back in. I am thinking maybe the spark plugs could possibly be hooked up in the wrong order, does anyone have a diagram of the order? Could it be the crank position sensor? I put all new plugs and wires in it also as well as a new o2 sensor...

**stlmo_gtp** · 05-15-2011

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

**01gpgt01** · 05-15-2011

surging idle is usually a vac leak

**Z34Phoenix** · 05-15-2011

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.

**balterbuilt** · 05-15-2011

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 =)

**balterbuilt** · 05-15-2011

also, the boost bypass actuator when at idle pins itself, i don't kopw much about that, is that typical?

**dsmuts** · 05-16-2011

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.

**balterbuilt** · 05-16-2011

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?

**Z34Phoenix** · 05-16-2011

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

**balterbuilt** · 05-16-2011

Jim's performancE did the wiring and tune, I'm shooting him an email right now. How would that affect it? I would think he would have deleted the tranny since it's set up as a stand alone system.

**BillBoost37** · 05-17-2011

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.

**balterbuilt** · 05-17-2011

97 grand prix is the base motor. do you guys think maybe my knock sensors are bad? would teh crank sensor have any affect on that?

**BillBoost37** · 05-17-2011

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?

**balterbuilt** · 05-17-2011

I did not touch the knock sensors. What do u mean by a case/crank learn? Gas could be suspect, I used what was in my fuel cell for the old motor which ran regular, I added 108 octane boost but who knows if that crap works

**BillBoost37** · 05-17-2011

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.

**balterbuilt** · 05-17-2011

i just read up about the computer relearn, i email jim at jims performance about doing that, i figure he would know best. would it hurt anything to just do it anyways? I have about 5 gallons of fuel in the tank right now, how much xylene would you recomend adding to that?

**BillBoost37** · 05-17-2011

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.

**balterbuilt** · 05-17-2011

i jsut looked it up, basically 30% xylene 70% gas, alright, luckily i got rained out of work today so i'm gonna run to the paint store and get some and try the relearn and the xylene, i'll let you guys know what happens. thanks for all the help so far everyone!

one question about the security relearn: being that my motor is set up as "stand alone" and installed in a 1966 cj5, will there be any issues? or will it just relearn what the computer was reflashed around (just the basic sensors to make the motor run)

**BillBoost37** · 05-17-2011

Remember to give it a chance to get the fuel down the line, and ... you probably want to reset fueling etc when you get that in.. so the pcm reacts faster.

**balterbuilt** · 05-17-2011

looks like xylene and tulouene are no longer available for sale in california...MEK? to reset the fuel trim, is that where you disconnect the battery for an hour or so?