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Hey. Here is the deal, after baffling multiple mechanics, my car still has ROUGH cold start ups, and rough/high idle.

When I start the car, it feels like Im sitting in an old muscle car, the engine chugging along, and the exhaust sounds similar, Idle sits around 1200rpm. I give the car any gas, and it actually drops the rpms, and it just runs rougher. After 5 minutes the engine will idle at 1100rpm, and will run a little rough. After a quick drive, or any driving the engine will idle at 1500, drop to 1000 then to 1500, then to 1000, and stay. I have pulled codes, the code I get is for the front O2 Sensor. I am running a curved neck intake manifold, a 'remapped' ECU, 1.8L MAF/VAF, KLZE throttle body.

Anyways, I am tired of going days at a time, with my car in the shop while the mechanics scratch there heads, and I have to borrow rides from friends.

The deal is, ANYONE that can suggest the solution, that actually works, and gets my car running properly. I will paypal them $50USD.

- Carlos

Its probably the ECU. Everyone says the remapped ECUs are crap. Sell it and cop a real ZE ECU from somebody. It'll most likely solve your problem.

Hey not sure if your suffering from the same problem as i was but sounds similar to what was happening to my GS engine. The Problem was the disty going bad. Wasn't bad altogether but it was on the way out the door. But don't just go out and buy one to see cuz its pretty damn pricey. See if you have a ways to test it first. I hope this might help ya for a bit.

engine mounts ?
vaccum ?
not firing on all cylinders ?
Distributor ?

those are the only things i can can make your engine go retarded like that.

Originally posted by Illa Killa:
Its probably the ECU. Everyone says the remapped ECUs are crap. Sell it and cop a real ZE ECU from somebody. It'll most likely solve your problem.

That ECU was in my car for a long time and I never had a problem with it. It seems like your idle speed sensor is gone or the wire from the idle speed sensor to the ecu is damaged. Do you have the "TB coolant bypass" mode? That could be it too.

"TB coolant bypass" mode? Wtf?! how do I get it outta this mode...? or tell if its in that mode. I have a spare TPS, so I can always swap that over

What ECU are you running. Please be detailed. Does your car's exhaust smell "rich" and is sooty/black? Would you say that you run too rich? I think it IS your ECU.

Originally posted by Talon_66:
"TB coolant bypass" mode? Wtf?! how do I get it outta this mode...? or tell if its in that mode. I have a spare TPS, so I can always swap that over

It's not a mode; he probably meant a modification. It's removing the coolant supply & return to the throttle body. It's supposed to make the throttle body cooler, but it promotes icing in cool wet weather. Bad idea!

<small>[ May 07, 2004, 02:53 AM: Message edited by: IanL ]</small>

Change your distributor and change both O2 sensors..problem solved.

Worked for me, now my ZE runs like a top

I had the EL Prototypes (cork sport) re-coded ECU, it ran like crap when cold, black smoke rich, miss-fireing on acceleration ect... untill it got warm.

poped in a KL-36 ECU runs like a champ now.

you may haev a vaccume leak?

also May have a bad disty.

1 quick test is to swap in a KL-03 ECU and KL-02 VAF from a probe or MX-6 and see if it helps, then you know its the ecu.

Curt, I got everything u described! Cold start, mis-fire, black sooty exhaust. I might switch back to my original ECU to see if it makes any difference. No vacuum leaks though.