95 dies then runs ok for weeks

[Monteone]

My 95 GMC Z71 dies when I apply the brakes to stop.
It started about a year ago. It will do this then run great for several weeks. It used to not die completely, but enough to get my attention. Then it would die but start right back up. Now one time it set for about 15 min while I was looking for a buddy and a trailer the started and ran 5 miles home with no trouble then I tried it several times and it started every time.
After this episode I replaced the pickup coil, ignition module, ignition coil, cap and rotor and wires. I have also replaced two egr valves.(i don't think the 2nd one was bad but it was under warrenty).
Then it died about five times in the last two blocks to work then wouldn't start at all. Seven hours later it started and ran fine.
I took it to a shop and the guy checked the fuel pressure, the injectors the ecm and harness and everything I allready changed. He can't duplicate my problem. He has had it for four days! He has driven it and is stumped like me.
I talked him into changing the fuel pump, but he doesn' think that is my problem. I get her back tomorrow and will hope for the best.
Any ideas would be helpful.

Monteone out.

[75K30]

Welcome to the site Monteone:
The relationship between the brakes and the operation of the engine should tell us that the common factor is the place where we should start looking. If this is a 1500 and it has vacuum brakes, then you might have a vacuum leak, and the leak is in the booster. May try to stomp the brake pedal with the truck in gear, and not rolling. Just right in the drive way, witht the parking brake on. Don't try anything fancy, just a good smash on the pedal. If it dies, disconnect the vacuum line to the booster and try it again you will have to plug the line or the truck will run terribly, and the pedal will be tough to push, but it should not have an effect on the rpm. This would indicate that you are getting closer to finding the leak.
Now if the truck is a Hydro assist, you may have another set of problems that is related to the hydraulic system. Is the power steering giving you trouble as well? Could be that when the brakes are applied, the pump has to work extra hard, and is putting a bit too much of a load on the ruck at idle, causing it to die. Try to get the truck to die to the point that you can duplicate it, like hard stops or something, or even turning the wheel, and hitting the brakes at the same time. You might need a pump for the hydro-boost. We have plenty of ideas, but we will need a little more info on your truck, and ned to really know the circumstances in which the problems occur.

[Monteone]

I have tried the brakes both gently and smashing the pedal and got nothing.

I have noticed that for the last few months that I have to push the pedal down harder than I think I should to get the truck to stop.

Is there a valve or something in the booster that could be sticking?

I ran a vaccuum test a few months ago, and the engine is running to spec.

[bountyhunter]

sounds like bouster prob to me

[Monteone]

I got it back yesterday. The guy replaced the distributor shaft. He said he thought maybe the magnets were getting week and not being read by the pick up coil at low rpms.

I've put about thirty miles on her and no problem yet.

[Monteone]

It turned out to be the ignition switch after all.

[rbmcveigh]

Do you mean the starter switch, like where the key goes? Just curious because I think I am having the same problem with mine, been fighting with it for 2 weeks now.

[scavanger]

I will do the same I think I did with Monteone, I will give you the link to my thread. Hope it helps.

http://http://www.truckforum.org/for...ead.php?t=9326

scavanger

[rbmcveigh]

That link is dead

[Moostang]

I believe this it the thread he is referring to
fuel problem