Cold Start Misfire 89 Pathy VG30I V6 TBI

[krmiller07]

Has anyone experinced a cold start misfire or "rich" running condition until the water temp rises? I have an 89 Pathy VG-30I TBI. And upon cold start it immediately goes to fast idle, however it also misses a little and runs like a carborated engine with the choke not opening all the way. Aslo wondering if the engine will run this way when the cam timing is off a tooth or more. I had the T-belt replaced about a year ago (5k miles) and a recent mechanic said the cam timing could be off a tooth?

He also claims theres no change in idle when he pulls the #1 and, or #3 plug wires off?

 

This is driving me crazy! I've done a complete tune up. Filters, plugs, wires, cap and rotor, O2 sensor and water temp sensor. No codes, and runs fine when it's warm or at operating temp. Makes normal power, but gets horrible mileage.

One shop told me it's a intake gasket leak, one shop said I've got fluctuating comperession in one cylinder ( Not confirmed ) I pulled the plugs and the passenger side plugs were a little wet, and one was wet and carbon fouled. I had poured a couple of bottles of Techron in a 1/4 tank of gas in an attempt to clean the injectors and burn out any carbon deposits on the valves. I've read about every posting I can find on here and the other Pathy forums and still can't figure it out.

 

Any ideas out there guys?

 

Thanks,

[MY1PATH]

which temp sensor did you change? the one on the manifold is for your guage the one screwed in the Cyl head is for the ECU and that controls warm up ratio.

 

Hows your spark timing. 12~15 deg warm? are you sure? if your balancer has slipped(uncommon) or turned due to a worn keyway (common) you will get a false timing reading. so if it says 12 when its really 5 then when you cold start its fireing at 0. I'm pretty sure anything less than 4 will cause a miss.