Will a Blazer crank if the IAC valve ( Idle Air Control ) is unplugged ??

 

I haven't tried it, but they should crank, start and run with the IAC unplugged depending on the last setting of the IAC valve. If it was unplugged after it was warm, the setting of the IAC will probably be too far closed to keep it running. So it may stall, but it should crank and atleast attempt to run.

Why? What's up?

 

I had to change out the cpi, and the fuel lines, and I have everything back together and now the engne will not start. the aic was unplugged, but I got it back on, but still won't crank. fires at times, but mostly just spinning the engine. everything looks good just won't crank. any thoughts

 

Sounds like it's cranking, just not firing. Have you vented the fuel lines? To vent the lines, turn on the key and put a rag around a screw driver and push down on the fuel pressure test port shrader valve. Once fuel starts to spray out, you're done.

Also, did you remember to plug your MAF sensor back in? ('95s have MAFs don't they?)...

 

are you saying you have to vent the fuel lines? will it cause air to be trapped? and yes the map sensor is plugged in

 

I don't know if it is absolutely necessary, but I have always vented my fuel lines whenever I have opened up the system.

Things to verify are fuel, air, and spark. Also, go over everything that you took apart, plus anything that was near where you were doing work.

Also, I have heard it many times that on the CPI engines, to purge the system and inspect for leaks with the upper plenum off. Just turn on the key to energize the fuel pump.

 

venting didnot do anything. of course after each purge the pump has gone off, but still not cranking. should I take all that stuff back off or not, don't smell gas, which I did when I had the lines leaking under the plehem

 

OK, well, that was just to make sure that something wasn't air locked.

Anyway, I would check everything over acouple of times. Make sure that nothing is disconnected especially the coil wire. Take the coil wire off and reseat it on each end. If you have used any dielectric grease on the terminals off of the distributor or on the spark plugs, make sure that the boots aren't air locked and pushing off of the terminals.

 

Got some engine starting fluid in a spray can? I keep it around for simple decisions. Is it a spark, gas or air problem. If it backfires with squirt of this stuff and cranking, at least you know you have spark.


Why did all this have to be done?