Reader Question: I have a 1997 Chevrolet Blazer v6 4.3L engine 109,000 miles. Since the cold started, I have not been able to get it started right. It will turn and rumble, but will not ignite.
I can get it started after about 5-6 turns and when it starts, it runs great and I can start it all day after that.
It had a new pump installed 20,000 miles ago and I checked the pressure both when it started and when it will not. I am getting 59 PSI so I do not think this is the problem.
I changed the fuel filter, full tune-up, new ignition coil and a new battery and I am still having this problem.
What else could it be? Is it an ignition problem or the regulator, injectors?
If you are sure about having proper fuel pressure AT THE ENGINE, then I would turn my attention to lack of spark or lack of spark timing as the culprit. Check spark at the spark plugs.
If you do not have spark then work backwards to the distributor to find out if there is spark out of the distributor. Its gotta be lack of spark, improper spark timing (ignition module/distributor problem) or a lack of fuel pressure.
If this engine is using the “Spyder” type fuel injector, they are notorious for leaking raw fuel internally thus producing a longer cranking time to start.
I cannot remember when they started using that large injector to be honest and I am away from my shop so I do not have my manuals with me.
You can sometimes smell and see raw fuel leaking on the back center section of the intake manifold, and smell raw fuel in the oil crankcase.
Reader Updates: Well, I have checked the spark and everything else and that is fine. A mechanic says it is the fuel pump, but I really can believe it would be that because once it starts in the morning, it would start great the rest of the day.
If it were, the pump it would not start would it. He thinks that it has good pressure at key on, but the pressure drops as you crank it and he thinks the pump is not putting out enough volume. If it is dropping off at crank time, would I have a leak in one of the lines or in the injectors or the regulator? How can you be sure what one it is?
I read something about checking the intake manifold valve for signs of washing. Is this a good place to start? It has a CSFI unit, which has separate injectors going to it and a regulator. How can I test the module and the ignition switch to see if they are working right?
I think this is probably a lack of proper fuel pressure too. You need to hook up a manual fuel pressure gauge you can screw onto the fuel rail under the hood…then watch the gauge as you crank the engine.
I have seen similar issues with fuel pumps, they are weak and slow to get pumping, but once they have been operating for a while they can pump the rest of the day with little incident. You can sometimes bang on the bottom of the fuel tank AS someone cranks over the engine. This can help jump start a weak fuel pump.