Strange Idle/Hard Starting Cold

[kerplunk318]

I have a '90 with a pretty much new engine that has just recenty been giving me problems. When it is cold it wont start unless im on the throttle a little. If I dont do this it sounds like it fires a few revolution and stalls. After it starts with my foot on the gas I have to warm it up so that it runs right. If I dont, it stalls or runs at less than 500 rpms. When the truck is hot it starts right up but runs a little faster than it should, around 1100-1400 rpms. Some help asap would be appreciated because Im hittin the trails in a few weeks and I want her to be up to par. thanks a lot
Louis

 

[badmix]

Youll have to provide more info. Like is it Carb or TBI? etc.

 

[kerplunk318]

Its a pretty much stock '90 so its a 350 tbi, it does have a throttle body spacer, headers, and a high flow exhaust. Also has power pulleys, there are no trouble codes. It has a new distributor, plugs, wires cap rotor, ign module and rather new msd wires. The internals of the engine are factory specs. I have had this motor in for over 3 years and this problem just started happening. thanks

 

[dyeager535]

Do a good visual inspection of the engine and wiring/vacuum lines, then I'd suggest checking out the ECM temp sender.

 

[kerplunk318]

Do a good visual inspection of the engine and wiring/vacuum lines, then I'd suggest checking out the ECM temp sender.

There are no vaccuum leaks and all the wires appear to be ok. How do I test that sensor? When I unplugged it the car would not start at all (when cold.) They must be pretty cheap, should I just get one and see what it does? it definately looks pretty old. thanks for your input

 

[dyeager535]

You COULD swap it out, but I know somewhere the resistance values are given. Might even be in my TBI/TPI/CCC troubleshooting thread.