hard cold start

[krek007]

Hey guys, Just recently replaced the kids 305. He neglected to add oil to the crankcase and blew it up... anyway slapped a rebuilt in last weekend and it runs fine. I am however having some coldstart issues...It idles and runs fine once started, and has no problems after it's warmed up. I have replaced most if not all sensors including new distributer. Is there something else i'm missing? Does TBI have a coldstart signal coming from ecu?

[2000CAYukon]

The Engine Coolant Temp Sensor is in the intake near the tstat housing. This is the only way it knows it is cold vs warm. Check all the ground locations at the intake manifold and tstat.

Having it scanned will also tell you what temp the ECM thinks the engine is running (or starting at).

//2000CAYukon

[krek007]

Thanks Yukon I will check asap. I have a scanner and have gotten no codes, but will check again. How many ground wires should there be on the block. I have 2 in 1 crimp connecter mounted in front of the tstat, and one larger one from the block -frame..Should their be more? BTW, any ideas on how to bulletproof this motor for a 17 year old?

Ok coolant temp read 142 truck fired right off, but It had been running about three hours ago. I will check again a.m. and see what it says. I'm leaning towards ecu or fuel system. it has no high idle on a cold start and takes 3-4 start cycles to get running.

[2000CAYukon]

If you have no high idle (cold) and the temp looks acurate, then the IAC make not be working. The IAC counts should be different cold vs hot. If you pull the engine coolant temp sensor off while engine running (hot), the idle should immediately get higher. If not IAC would be the first place to check. It may just need to be cleaned.

I want to say, my 90 GMC K1500 has 2 or 3 grounds on the intake manifold. Will look again.

I have owned mine since new almost 19 years now and still have original engine/trans. I just keep up with maintenance and she runs good.

//2000CAYukon