Starting problem - 1991 Bravada - 4.3

[snoopybear]

I'm having an intermittent starting problem. Most of the time, it starts OK. But at the worst possible times, it won't start with 10 or 15 tries. At these times, if I let it set 15 or 20 minutes, it will finally start. It's showing no codes. All the ignition parts are now new. The injectors are pumping gas while it's cranking. Starting fluid does no good. Any suggestions as to what I might try?

[derhells]

I am having a problem that sound a lot like yours. The first place to test would be for spark. Then I would go to the fuel pressure. If you are getting spark the fuel pressure should be between 55-61 psi. Test this when you are getting a no start. I am thinking my problem lies in the fuel pump not giving enough pressure for the injetors to fire the proper amount of fuel. Pending any other possibilites from responses today I will be changing the fuel pump in the next few days and will let you know if that works. When I was getting a no start the pressure was anywhere from 50-54 and most of the time turning right over on the first try at 54 but oanything less and it is taking me several turns to get her started. This is all assuming you have the vortec engine. Let me know how you do and I will let you know my outcome also.

[snoopybear]

Even though my engine isn't a vortec (has round air cleaner), it sounds as though our problems are very similar, as you mentioned. At what point in the system do you hook up to measure the fuel pressure? Does it take a special fuel gauge? Regards

[derhells]

Originally Posted by snoopybear

Even though my engine isn't a vortec (has round air cleaner), it sounds as though our problems are very similar, as you mentioned. At what point in the system do you hook up to measure the fuel pressure? Does it take a special fuel gauge? Regards

I have been chasing this problem for about two weeks and hope to hell it is the fuel pump. On my bravada the schrader valve is located in the engine copartment by the fire wall and distributor. not sure if it is in the same spot one yours. Someone else here may have a better answer for you or if you have a repair manual that my tell you. The schrader valve is a place to screw a fuel pressure gauge in and turn the key to turn on the pump and it will register fuel pressure for you. I know I had a hell of a time finding a pump but then found that the reason for that was all of the parts places were saying it was not for use on gm vehicles, these were only gms with the tbi motor, and this is what you have so you may beable to use a different kind of gauge to test the fuel pressure. I would get a manual and you should beable to get this info. Also when was the last time you changed the fuel filter. Start small $$$$ and work your way up. This is the same thing a garage would do to you. When they fix something they tell you we replaced the filter and changed the blinker flued for you to because it will run better that way!!!! Also check the blazer page lots of info on that as well.