98Tahoe crank no start... sometimes

[CaseyA]

Your fuel pressure is low. Is that key on eng off? Running idle? Running highway steady state? My experience on this vintage is 60# min.

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

That was key on engine off. I'll have to check it now that it's running again.

 

[Eman85]

I'll try again. When it doesn't start you say it turns over OK. If that is the case then why the jumper box and the battery charger? As someone related fuel pressure seems low.
When it won't start cycle the key off and on multiple times, not cranking just off and on, and listen to hear the fuel pump cycle. The after doing that try and start it. If it starts it is most likely the fuel pump.
As in my first response if it cranks but won't start turn the key off and then to the on position and watch the security light to be sure it shuts off.

 

[muncie21]

If you've confirmed fuel pressure and theft system aren't culprits, look into the ignition system. When mine was doing this (years ago) I narrowed it down to the PCM or a component (don't recall the name) in the ignition system. Ended up selling it (with full disclosure of the history) before I was able to confirm what I did actually fixed the issue.

 

[Ralph]

crankshaft sensor

 

[CaseyA]

I let it sit a week and I have another no start situation. I haven't changed out any parts but I wanted to report that I checked the fuel pressure now that it's no start. With key on engine off its still 55-57psi but when cranking it goes to around 63psi.

 

[exp500]

Try key to run 2 seconds, OFF, repeat 2-3 times then START. Usually 2 cycles works. Once running, recheck fuel pressures including driving.
A weak fuel pump will not keep up on highway. Change fuel filters yearly at a minimum.
Sitting a week is the Max for these trucks 4 days normal. Due to battery drain. Some a little better some worse.

 

[CaseyA]

Just wanted to update everyone. I believe it was the distributor cap and moisture. Seems like it wouldn't start only after it rained and only would start after a week or more to dry out. I finally pulled the cap and rotor and they were very corroded. Replaced and it seems to be running great again. Wasn't a fuel issue... Thanks for the suggestions/help.

 

[exp500]

Set your scanner to monitor misfires, fuel trims, trans slip, and anything you see available. Watch it at steady state at various speeds. Say 35/45/55/65/75. Not knowing capabitities of your scanner.

Also start at the beginning and re-read the posts here. We can only suggest based on the info you provide. My next guess will be at speed your fuel trims will max out due to low fuel pressure.