98 z71 intermittent no start

[lit549]

I have a 98 z71 with the 5.7.Recently done cap rotors wires plugs fuel pump.Truck ran great for awhile ,it slowly started to be harder and harder to start.Check fuel pressure and its 58psi key on test,running its 52psi and raises when revved.Key on test,the fuel pressure drops pretty quick.I also poured gas in the throttle body when it wouldnt start ,it started and ran..ign module is and i have spark.I also replaced the coolant temp sensor too.Its worst when ya let it sit.If it starts then it starts fine till ya let it sit again..Im leaning towards fuel pressure regulater or spider..Also the security bulb does not flash when it does the no start so i dont think its the passlock system.Anyone ever have this issue?I have googled it and alot of people have the no start issue but mine will actually start eventually..Im stumped and tired of throwing parts at it,also no ses light or codes.Tbanks for any help..

 

[Black_cirrus]

You got it narrowed down to fuel, Your not supposed to loose fuel pressure very quickly. I'd say your probably right with the spider but could be the FPR, another option is in the tank, there is a check valve with the pump or I've seen the hose from the pump to the sending unit spring a leak.

 

[lit549]

I hope its not in the tank as i just installed this pump ..Brand new delphi from rock auto,plus i think its out of warranty.It ran great for a few months afyer install,then started the whole hard to start crap..

 

[Black_cirrus]

I'd guess spider myself they say you can inspect with a mirror down the throttle body hole, but I've never tried it. Try to turn the key to on and delay the cranking for 1 or 2 seconds to prime the system before you start the truck.

 

[lit549]

Thats exactly what i have been doing,ill do that 2 or 3 times and it seems to help,itll eventually start.I can hear the relay click on and tgen off as the pump primes,the pump is very quiet.The original was loud i could hear it from across tge street..

 

[Black_cirrus]

Yea, most the newer pumps are quieter then the 90's pumps, plus noisy pumps are sometimes a sign of failure coming. Some pumps are a different design altogether but I can't think of names off the top of my head.

 

[JasonLC]

I had the same problem with my 98 z71, wound up the cap and rotor, had purchased one with aluminum post, switched to one with brass post and all has been good since.

 

[lit549]

what did you end upngoing with?I installed the delphi 20010 cap and rotor..Ive looked and looked and no one even describes cap rotor with brass terminals..

 

[JasonLC]

what did you end upngoing with?I installed the delphi 20010 cap and rotor..Ive looked and looked and no one even describes cap rotor with brass terminals..

found it on amazon, took a bit of searching but i found one, look closely at the pictures and you will be able to tell, i think it was this one
AcDelco GM Distributor Cap (D329A) And Rotor (D465) Kit Vortec-8

https://www.amazon.com/AcDelco-Dist...86489938&sr=8-1&keywords=5.7l+distributor+cap

 

[JasonLC]

what did you end upngoing with?I installed the delphi 20010 cap and rotor..Ive looked and looked and no one even describes cap rotor with brass terminals..

also it was worse if it were very humid or had been raining