rough idle in first five minutes gas smell

[jenada204]

I just got a 944 that needs some help to restore it to its full beauty. Whenever I first start it up, I have to hold to accelerator down for the first five minutes until it warms up before it will stay running. During this warm up time it smells horribly like gas and smoke and fumes come out the tailpipe. If I let off the accelerator it dies and will not start again unless I change the spark plugs. I have changed the sparks plugs multiple times now. Its like they get wet and won't fire if the car shuts off before warming up. I just got a new MAF sensor and that didn't help. I don't know where to go from here. After it warms up five minutes there is no smoke no fumes and it runs like a champ all day long as long as you don't shut it off. As soon as you shut it off and restart again it does the same thing for about five minutes again. Please help if you have any ideas. I really like the car and can't wait to drive her. I am afraid to drive it in the condition it is in for fear that I am doing more damage. It has many miles 167,000 so maybe its just the enigine. let me know. thanks.

[carsonmx114]

you mentioned a maf, is it the stock flapper valve or a hotwire setup? it sounds like a overly rich situation but i don't understand why it gets better after the engine is warm. a rich mixture would get worse as the engine gets hot unless your car is leaning out as the temp comes up, or the cold start is timing out. there are two temp sensors in the head, one for the gauge and one for the fuel injection i think the one with individual wires on it between cyl. 1 and 2 under the intake is for the fuel mix. did it make any difference when you replaced the maf? if not i would put the other back on to rule out turning one problem into two. have you checked your air filter and your intake into the airbox? is your converter stopped up? i guess i would unplug the temp sensor for computer and see if it helps, if not you might try jumping the two sensor wires together and see if that helps. the warmer the coolant the lower the resistance so jumping them together should make the computer think the engine is really hot and call for a lean mix. post back after you work on it again.

[beatdown944]

open loop-car dies
closed loop-runs like a champ

[jenada204]

Hello
Thanks for the input. Today I worked on the car. I took the throttle body off and cleaned it with degreaser and that seemed to have helped the cold start problem. Now I have another. After the car runs for about 15-20 minutes I push on the accelerator and it just cuts out and drops to 1000 rpms. If I stop the car and take it out of gear then I can rev it all the way again. Could it be to do with the throttle position sensor or something to do with the clutch? thanks

[carsonmx114]

it may be the tps or the air flow meter. also check for air leaks in the intake system if air gets to the engine without passing through the air meter it will lean the engine out, the engine might rev with the trans out of gear but with a lean mix it wouldn't make any power at all.