Hard Start when Warm

[Dan_RL72]

HI all,

This one has me stumped. I ran a search without luck. It takes 2 or 3 tries to get the truck to start when its warm. Cranks and cranks and then finaly catches and runs bad for a minute or two, then its fine. Cold start has no issues. I changed the plugs and check Fuel pressure. Anyone had this problem? BTW I have a 2000 1500 with the 5.3.

[silverado man]

Most likely it is going to be your fuel pressure regulator. If you take the hose off at the regulator and gas pours out your regulator is bad. I had the same problem a couple months ago and after the fix I haven't had a problem since.

[danielross1005]

Could it be anything else? I have already replaced my fuel regulator and it still has the same issue as dan rl72.

[bikeyron]

I had a GMC Safari that did the same thing. It was a little electric black box that cost about $15. I am having the same issue with my GMC Sierra. I don't remember the electronic part. It cost me $50 to have it anaylized in "95". I'm sure it would be more than that now. If you get an answer let me know.

[RyanZ71]

Ended up being the fuel sending unit on my old 99.. FPR was fine.

[X-man]

HI all,

This one has me stumped. I ran a search without luck. It takes 2 or 3 tries to get the truck to start when its warm. Cranks and cranks and then finaly catches and runs bad for a minute or two, then its fine. Cold start has no issues. I changed the plugs and check Fuel pressure. Anyone had this problem? BTW I have a 2000 1500 with the 5.3.

 

I had a similar problem with my wife's Explorer. It was an injector leaking down. The leaky injector effectively flooded the engine which made for a difficult hot restart. But there was no problem when the engine was cold as the fuel presumably had evaporated out of the manifold by then.

You could try doing a pressure leak down check to see if it is within spec but you may have to plug the FPR return to isolate that as a leakdown source.

Good luck.