I have a '99 Blazer that I've owned for 10 years. Normally when I have a problem the check engine light comes on and I have an idea where to start, unless it's something simple like a dead alternator or water pump then the problem is pretty obvious. This problem has me stumped.

When the truck has been sitting for a long time, long enough to completely cool down, it doesn't want to start. The check engine light does not come. It turns over but never quite fires.

If I spray some engine starter fluid (a.k.a. ether) into the intake the truck starts up and runs fine. I can shut it off for a short period of time and it will start up again no problem. If I let it cool completely I have to resort to using the ether again.

While running it runs fine.

I replaced the fuel filter and air filter, but that made no difference. Didn't think it would since I'm pretty good about changing my filters.

I thought I might have gotten some bad gas, I ran the rest of the existing tank out and put some good fuel in along with a bottle of injector cleaner. That didn't help either.

A clerk at AutoZone suggested replacing the temperature sensor which I did but that hasn't helped either.

I don't know what else to try and since my pick-up got smashed in a accident this is the only vehicle I have to drive. Any help would be greatly appreciated. Thanks.

Tom

 

when you turn the ignition to run do you hear the fuel pump kick on? also when you turn the ignition to run do all your dash lights come on?

 

98+ No-Start - Engine Cranks OK

96+ Fuel System Diagnosis

 

Yes, the fuel pump kicks on and yes the dash lights up fine. It even runs fine once it's started. This is a cold start problem.

I looked at the 98+ No-Start - Engine Cranks OK and this seems to focus on a number of things that I think are good.

For starters, there are no engine codes to look at. They're all clear.

The spark plug wires are good and I'm getting spark. I do not believe this to be an electrical problem, rather some functionality like a choke. Which is probably and inaccurate description since this is all computer controlled now.

I read at another site to try cleaning the EGR valve with carb cleaner. I'm going to try that in the morning.

 

Did you do the fuel pressure test? It sounds like you have a low fuel pressure issue. These engines require a bit more pressure to start than they do to run.

The EGR cleaning is a good idea. I would also recommend a MAF sensor and throttle body cleaning (including the IAC bore). Here are some threads that can help with those tasks:
MAF Sensor Cleaning
EGR Valve Cleaning
How to remove Throttle Body 2nd Gen 4.3

 

Well, I cleaned the EGR valve and intake manifold. But it didn't help. I did find that I was missing the gasket for the EGR valve luckily I had already bought a new one when I decided to clean it. I checked the mass air flow sensor and it was pretty clean so I didn't mess with it.

I have not checked the fuel pressure since I don't have a gauge. I may take it to the base auto hobby shop to test it. I'm still not really convinced that it's a fuel pressure problem since once I've gotten it started and ran it for 5 mins it starts again just fine.

Does anyone one know what the truck is actually doing when it starts cold? Want sensors are involved?

 

Yep, next step, check your fuel pressure.