Need help with TBI!!!!

[Supreme70]

Ok I have a 87 stock 350 with the tbi on it ans here are my problems, after I runn it for awhlie and stop somewhere say for 5 to 10 min's I have a really hard time starting the truck, I would say about 7 tries to start it. also when its cold out it runs like sh*% till it is totally warmed up. next when it's wet out is runs like crap acts likes it loading up when i try to jump on it. No here is what i have done so far, Changed the O2 senser, changed throttle postion senser, changed fuel pump relay, did a full tune up on it with ac delco part, I.E cap, rotor, plugs, and wires, I have no vacum leaks that i can find and I put a stock, air filter back on it, it had an open element on it when I bought it. The timing is at factory spec too. im about to rip the stuff off and go carb. and older style distributer. Please help.

 

[Thunder]

Doesn't sound like anything too serious. Dont panic
Ok. First have you checked for trouble codes? Should do that anytime you are having problems.
if you dont know how Go here:[URL]http://www.troublecodes.net/GM/[/URL]
If any codes come up post the number.
Just off the top of my head it sounds like your problem is either a stuck open EGR valve/bad egr solenoid. Or a bad Coolant temp sensor.
When you set the timing did you disconect the timing bypass wire?

 

[4X4HIGH]

I second the CTS (coolant temp sensor). Maybe not all of your problem but at least a good place to start with the running crappy part.

 

[Supreme70]

where is the cts located???? no i didnt unplug the timing by pass wire what color is that wire so i can do it right.

 

[4X4HIGH]

where is the cts located???? no i didnt unplug the timing by pass wire what color is that wire so i can do it right.

The CTS is next to the water outlet on the intake manifold, it will have a connector with 2 wires.

The EST (electronic spark timing) is a single brown or tan colored wire near the brake booster, just unplug the wire, adjust timing to zero, turn off engine then plug back together.

 

[Thunder]

IIRC pickups have the est wire in a different place than Blazers.
If you cant find the EST bypass wire next to the brake booster try looking on the firewall on the right of the engine. The emission tag on the radiator support tells you where it is at.
That wire must be unplugged to set the base timing right. If not. Timing will be way too far retarded.
Get your timing set to 0 with the wire unplugged. Turn off engine reconnect. Start drive it a bit. See if that helps you before you do anything else.

 

[4X4HIGH]

Other most common place is under the dash below the glovebox on trucks.

 

[Supreme70]

Thanks guys I will check the timing out tomorrow and look at the cts senser, Ill let you know what happens.