'94 GMC Sonoma 4.3 'z' Vin Cold Start Problem

[FortressofRust]

Ok, when its cold it idles rough. Wobbly about 500 RPM. If I give it gas up to about 1800/2000 ish. The idle takes off up to about 2500 on its own then after 5 to 10 seconds gradually lowers down to about 1000 and then down to 750 and runs smooth. Its fine the rest of the day. Just that first ice cold start. Sometimes it takes alot longer like this morning to smooth out maybe a minute or two and this morning I could smell gas. I think its getting to much gas and flooding.. I replaced the TBI gasket already because I had a high idle problem previously and found that was the cause. But I don't think I had this problem at all when the gasket was bad and sucking in air.

[j cAT]

Originally Posted by FortressofRust

Ok, when its cold it idles rough. Wobbly about 500 RPM. If I give it gas up to about 1800/2000 ish. The idle takes off up to about 2500 on its own then after 5 to 10 seconds gradually lowers down to about 1000 and then down to 750 and runs smooth. Its fine the rest of the day. Just that first ice cold start. Sometimes it takes alot longer like this morning to smooth out maybe a minute or two and this morning I could smell gas. I think its getting to much gas and flooding.. I replaced the TBI gasket already because I had a high idle problem previously and found that was the cause. But I don't think I had this problem at all when the gasket was bad and sucking in air.

check all the vacuum lines and you have many. esp around the TBI. then make sure that the TBI air cleaner has the hot air exhaust manifold tube hooked up. I would also wrap some high temp wrap around this flex tube to aid in heating the air up.

[FortressofRust]

Thanks! I haven't had the chance to check the lines yet but I will and I'll post what I find.