I have 1998 Chevy ext. Stepside truck It will not start after "mechanic" changed the fuel pump twice now. He says it's the computer that need to be replaced. I don't think that's right.

You ordered the pump replacement, then it runs a while and you order another pump, now stopped again, forget the pump its good. something else is starving this engine. What about clogged catalytic converter? maybe he found the computer stops energizing the pump at times. who is the diagnostic one here?

Thanks but he told me the computer needs changing the first time. He supposedly changed the fuel pump at it was working. The stereo works and all with key on when truck is not running. The catalytic converter has not been changed since 1998 the year of truck. He says he check computer but how if you didn't remove the stereo in dash where he says it is. Just feeling like he's dishonest to cover for other cost.

When the truck dies, do you lose power or ground at the pump? Are they both present KOEO, (Thats key on, engine off) but no pump? = connection at the pump. Do you lose power or ground when the key is turned to start? thats (when cranking) Could be the pcm shuts down the fuel. Why? no spark on most. or intermittant no spark. On some there is an oil pressure circuit. see if your wire diagram contains this, for your year and engine etc. You have to run real tests and continue testing till you have proved out the circuits. If your tech has good reasons, he may be copying a truck that he once fixed but hard to explain. You could believe him, or pay to continue testing to prove it out. sometimes a module intermittantly lets the spark arc. This can make the pcm shut down the fuel. Throwing unnecessary parts at it costs more than testing it right. calling him a liar and a thief will just make him stop giving a dam, and doing what you say, thats on you. This is why GM has a service dept. Happy testing, my friend.

start with testing fuel pressure. It should read over 50 psi or it will not start. Fuel pressure should read 58- 64 psi when cranking. stop cranking engine and fuel pressure should not bleed off in 5 minutes.

you can always just jack up the radiator cap and replace the rest of the vehicle and everything should be fine. Lol

Thanks for your input to the diag, david, and that global solution is interesting. I was following this thread for some time. i have concluded that when we point the finger at our technician, we have three fingers pointing back at ourselves. He can get a 12V test light at a hardware store and verify power and ground, but he wrote in to tell us he does not trust the guy. We were asking him for basic info. Received nothing. He would not have the gauge for basic testing so I suggest that he find someone at the place he buys his fuel pumps to get him a test to verify.

We know a vehicle's computer is diagnosed by it's behavior, it's warning light or message center, and it's service bulletins, recalls and our experience. They were even kind enough to give us self test capability and an ALDL, then the OBD II standardization laws have decreased the trouble with confusion and put the tester in the customer's hand. He can get one on a credit card and return it after if his parts manager trusts him. Let's see if he really needs the global solution ? Or just to verify the first few checks and tests. Being that his parts store can defect his pump and give him another? perhaps he will disturb the connection then and it will do this all over again, then he can reread what was shared here. Thanks for reading.

I gave this a quick run through on my own truck and We were taking something for granted, If I neglect to change my filters, my new pump has to continue forcing fuel through the old, plugged filter. If that was what wore my old pump and resistance hurt the wire connections, my new part cannot expect much. If my tank is recycling the same dirt ? The process repeats, I would need to replace the fuel or put it in a pickle jar and let it sit capped, pouring off the top to re use the product. That's what a farmer did before he was forced out of business by smart people.