no start when cold

[just a number]

1999 gm 1500 4.3 v-6

Hears the info that I've got so far. It'll start fine when the engine is warm, but it takes 20 mins of screwing around to get it to start when cold(12hrs+downtime). it's also developed a lack of transmission kickdown. don't have the codes read yet.

best guess so far is the TPS?

 

[robzombie4551]

Poss. CTS if it runs fine once running.

 

[just a number]

it runs fine once started. would the CTS affect the transmission?

where and how do you check the CTS?

any other things affected by the CTS?

 

[just a number]

Update:

Well hears some more strange news on it. he was checking a couple of things and notices the throttle cable was loose. turn out it didn't return all the way. now it starts just fine. I gotta admit I'm curious what a slightly open throttle would cause a no start??

gotta find out if I shifts OK or not.

 

[woodchuck2]

Slightly open throttle will give it too much air. I would still check that the coolant temp sensor is reading properly anyway.

 

[Ed HD]

Starting and idling are affected by the IAC, and if the throttle is open the IAC motor can't do its job.

 

[just a number]

IAC=idle air control?
where and how to check?

CTS, also where and how?

 

[Ed HD]

IAC = Idle Air Control. This proves that it is working correctly. The throttle being open partially bypassed it. It's generally on the throttle body.

 

[THEFERMANATOR]

IAC = Idle Air Control. This proves that it is working correctly. The throttle being open partially bypassed it. It's generally on the throttle body.

The throttle being opened can cause a no start due to pretty much every gasser ECM being programmed with whats called a flodd clear feature. If by some chance you happen to flood a fuel injected engine, your supposed to push the throttle open to about half way and this will enable the clear flood portion of the ECM which completely cuts off fuel to the engine until it reaches roughly 400-500 RPM's(a running engine). The IAC would have nothing to do with it not starting in a situation with the throttle open as the throttle blade would be letting in more air than the IAC could which would result in a revving engine on start up.

 

[just a number]

here's what I'm thinking. I'm wondering if the TPS is misreading and tripping the flood control. might explain the lack of kickdown.

any thoughts?

 

[THEFERMANATOR]

here's what I'm thinking. I'm wondering if the TPS is misreading and tripping the flood control. might explain the lack of kickdown.

any thoughts?

Could very well be. If the TPS goes it can cause a no start, a revving engine on start-up, hiccups on accel, and a trans that won't shift. Also a dirty MAF sensor can cause all of these same problems.