Car runs after first start for 15~25 seconds and stalls - restart it - does the same

[89DodgeSpirit]

edit: This post is concerning my 87 2.2 T1 LeBaron Convertible that I recently rebuilt with a T2 turbo T2 Logic module and an 89+ Turbo1 intake manifold/throttle body/AIS/TPS.

Hey! I was talking about my bouncing idle from 1000 to 1100 in park and how it was rock solid at about 750~800 in gear.

Well when I start the car and leave it in park it will rev to 2000 or so right after start and promtly drop down to about 1500. After 15~25 seconds it almost seems like it's trying to lower the idle and does it too much or too fast and the car drops down to 200~300rpm or lower and just flat out stalls. If I hit the gas real fast at the 200~300 range I can bring it back to life before it dies.

This is getting on my nerves - as I have to push the gas and hold the revvs at about 1500 before I can drop it in gear or it dies on me. If I drive it a bit and park it I can put it in park/neutral and it will rev from 1000~1100 up and down but will not die on me - it only happens after a fresh start.

Timing last I checked (last week - done nothing to it since then) was at 12degrees BTDC cam and crank timing are good O2 seems to be functioning normally (A/F gauge) but O2 *shouldn't* cause such a problem so close to start (comp's not reading gauge till it warms up right?).

I was thinking either bad map sensor or bad AIS - but I don't have extras to swap in so I'd like to pinpoint the problem BEFORE I buy the new part =)

Any assistance is appreciated!

edit: Going out to pull codes - last time I checked (even with it doing this) I just had 55.

Mike

[89DodgeSpirit]

When I get my diagnostics scanner - what do you guys recommend I check first to try and solve this problem? It doesn't do this once warmed up (in open loop as I believe it is referred to)

Only when the engine isn't listening to the input from the O2 and the other things that it does when it's cold.

Mike

[minimopar]

Problems with the vacumm lines to the MAP circuit can cause some really strange things at idle. Could also be a TPS issue. The scanner should help you tranck it down pretty quick. Also check the vehicle speed (speed/distance sensor).

[89DodgeSpirit]

Speed distance sensor is brand new and working fine.

This idle problem only happens just after I start the engine - if it's warmed up it will idle perfectly fine in gear or out of gear.

If I start it , rev to 2grand with the gas pedal and drop it in gear I can sit there with the brake on all day and it will never stall - but if I start it and leave it in park it will idle for 20~25 seconds and die.

I swapped in a brand new TPS and that didn't solve the problem so I returned the TPS to AutoZone =)

Also when I first put it in gear after staring I have to rev it to about 2 grand before I do - otherwise it stalls the engine. When I drop it in gear it goes "kerTHUNK" and the car lurches a small bit. It doesn't seem to do this when warmed up - I can swap gears without a problem.

I'm not getting any codes (55)