I'm having a problem with my blazer (98 LS 4x4) not starting when its really cold outside.
I talked to a friend and he thougth it was the ignition coil, so i replaced that and it ran fine for a few days, but its back to not starting. It seems like its not getting spark, it will crank over and over and over but it wont start. But when it is running, it runs perfectly fine. I thought it could be water in the gas, but since it runs good when it is running, that rules that out.
I'm thinking distributor cap, and rotor, but before i go droping 30 bucks on that, i thought i'd see if anyone here has an idea.

 

How old is the battery and have you checked its connections and had the alternator tested?

 

The battery is good, it will crank over just fine, and i can sit there and crank for 20 minutes without the battery dying.
I never really thought the alternator could have been the culprit, so I've never had it tested. But i think you have to have it running to test it at Advance Auto (the only place i know that will test it for free), so that's out of the question.

 

I don't know about AA, but an alternator can be bench tested. Just remove it and take it to a place that can do the test.
Moving on, have you tested the fuel pressure with a pressure gauge?

 

yup, i used a feul pressure gauge, and the fuel pressure is fine.

 

Since it only takes three things to start the engine - fuel, air, and spark - and if the fuel pressure tested okay (we'll just assume that air is getting to the engine) that only leaves spark. How long since the last tune-up (plugs, distributor cap and rotor, fuel filter, and ignition wires)? BTW, what was the reading on the fuel pressure when you tested it?

 

When i bought the truck (like a month and a half ago), the guy i bought it from said he had a tune up done within the last month or two. Now weather or not he actually replaced the cap and rotor or just wires, I'm not sure.
The Fuel pressure reading was like 55 i think.

 

anyone have any ideas?

 

I have seen the IAC (Idel Air Control) cause this. But I would remove the two screws and take a look under your Cap and see what they look like. This will give you a good idea if it has been changed or not. And if you look at your plugs (though they are suppose to last 100k miles) you can see by any rust build up on the plugs to get an idea if they where replaced. After only a few months, they should not look like your exhaust manifolds (coated in rust).
If you have an OHMs meter you can test out the TPS and things like that. I am sure that some of the wonderful walking referance books here would be willing to input what your parts should test out at.

I just finished working on a 94 that had a simular no start on cold (then progressed to a no start at all). It turned out to be their FPR. But theirs also would run for about 20 min to 1/2 hr then die. So it had more issues then yours. It also had a wonderful light show in the dark under the hood (got to love those exposed spark plug wires).

 

alright thanks FreeBird, i'll check that out.

I was talking to my friends dad (a mechanic for the local GM dealership), he said pretty much the only two things it could be is the distributor cap & rotor or the ignition module.
Does that sound right to anyone?
I was thinking if i can see that the distributor cap hasn't been replaced, i'll replace that. If it doesn't fix the problem its probably the ignition module. (which i hope its not because thats expensive)