Author Topic: Just about had it... (Read 2248 times)

kenny kustom · « **on:** March 15, 2007, 05:59:46 PM »

I'm about at my wits end on this one. Here's the story. I have a 1989 yj with a 94 2.5L with about 20k on it. I put on the Avenger Supercharger. Ran ok. I put in the Split Second Air/Fuel/Timing FTC1 computer with a base map to get me going. Ran better. I took the jeep to a performance shop to tune it on the dyno. Ran GREAT. About a month later, it started getting harder to start. Longer crank times and a rougher, sputtering idle. Still ran good under load. Then it got worse, it would stall going around corners at idle, and would sputter, high idle and stall at a standstill.

After it would stall, i would have to wait about 5 min, then it would restart, otherwise if i didnt wait it would just crank.

So i started throwing parts at it. Performance Dist. Firepower kit ( cap, coil, rotor, plugs, wires ) Better idle but still stall. Then i found the crank sensor had melted to the downpipe. Replaced. Still problems. It doesnt stall, but it idles at 1k and under load it pops and sputters quite often... ANY IDEAS BEFORE I BURN IT ? ??

Bnine · « **Reply #1 on:** March 15, 2007, 07:05:30 PM »

Sounds like timing or a sensor issue. Sure the TPS isnt bad?

Rotten wire or bad plug?

Bad wire on that crank sensor?

Just a few ideas.

kenny kustom · « **Reply #2 on:** March 15, 2007, 07:33:39 PM »

Ignition system has been replaced..

kenny kustom · « **Reply #3 on:** March 15, 2007, 07:34:17 PM »

New crank sensor

bae146 · « **Reply #4 on:** March 15, 2007, 08:18:25 PM »

I had a friend with a 92 yj who had the same symptoms you spoke of. It turned out to be his fuel pump in the tank went bad. Something to check. Put a fuel pressure guage on the manifold and watch it for fluctuations. Good luck!!!!

kenny kustom · « **Reply #5 on:** March 15, 2007, 08:27:47 PM »

Did that... solid constant pressure. only 34 psi though

Rookie · « **Reply #6 on:** March 15, 2007, 09:21:25 PM »

Did u try resetting the computer after u replaced the crank sensor

Disconnect the positive battery cable for five minutes then short it to the negative cable for 30 seconds then reconnect

kenny kustom · « **Reply #7 on:** March 15, 2007, 09:25:51 PM »

I can reset the factory ecu through my laptop when connected to the Split Second computer. And yes, i did.

Rookie · « **Reply #8 on:** March 15, 2007, 11:01:29 PM »

sounds like its a bad tps

BlackYJ · « **Reply #9 on:** March 16, 2007, 07:24:10 AM »

If you are running a supercharger, have you looked at replacing your injectors or cleaning them and also it may be a fuel pump issue because of the supercharger requiring more fuel.

cLAY · « **Reply #10 on:** March 16, 2007, 09:33:10 AM »

Three things caught my attention, superchager, long crank times and melted cps into downpipe.

How much boost are you running and are you monitoring your EGTS? I would check the compresson to see if you've blown/burnt the rings and lost compression.

kenny kustom · « **Reply #11 on:** March 16, 2007, 03:13:24 PM »

The blower came with very large injectors. Today i replaced the o2 sensor. That was a major contributing cause. I also found the main problem. A leaky intake gasket between the blower and the intake manifold. Air is being sucked in and the iac can't control idle. All the extra air is throwing off the A/F mixture.

cLAY · « **Reply #12 on:** March 16, 2007, 07:14:12 PM »

That would do it, glad to hear it was something simple. Just out of curisosity how much of a difference did the blower make in HP and MPG?

How is it compared to say a stock 4.0 or a small V8?

kenny kustom · « **Reply #13 on:** March 16, 2007, 07:18:41 PM »

I got about 130hp at the rear wheels. So that should put it close to 200 at the motor. Mpg didnt change much. But who cares. I got big power, with all my weight behind the front axle.