99 Suburban 2500 7.4L Hot/Warm start problem (long time cranking)

[Revenelson]

I have a 99 Suburban 454 with 74,000 miles on it. It starts normal in the morning, but after driving it and turning it off for a half hour or more, it has starting problems. What I mean by starting problems is that it cranks for 5 to 10 seconds before starting.

Once it has started there are no performance issues, it runs great.

Advice so far:
Fuel pressure regulator (allowing pressure to go down), or Fuel injectors leaking down (causing flooding condition).

What I have tried: Replaced Fuel pressure regulator: No change

What I plan next: Purchase Fuel pressure guage to get more data points.

Is there anything else I should look at before ripping out the Fuel injectors?

Thanks in advance for the advice....

Steve

[bndfishing]

Crank sensor, ign module, plug wires. Resistance goes up with heat so if your wires are old and going bad you might not be getting good spark.

[010175]

.I have a 1999 with a 5.7 and it was doing the same thing. I did the presser gage test first. It would not hold fuel presser. Replaced fuel pressure regulator and fix the problem. You might try -search this site- for more help

[mxz600]

Originally Posted by Revenelson

I have a 99 Suburban 454 with 74,000 miles on it. It starts normal in the morning, but after driving it and turning it off for a half hour or more, it has starting problems. What I mean by starting problems is that it cranks for 5 to 10 seconds before starting.

Once it has started there are no performance issues, it runs great.

Advice so far:
Fuel pressure regulator (allowing pressure to go down), or Fuel injectors leaking down (causing flooding condition).

What I have tried: Replaced Fuel pressure regulator: No change

What I plan next: Purchase Fuel pressure guage to get more data points.

Is there anything else I should look at before ripping out the Fuel injectors?

Thanks in advance for the advice....

Steve

Mine did the same thing and when the manifold leak was repaired, it was found to have a bad check valve on an injector. It dripped fuel when the key was turned on so it would start fine when cold and basically almost be flooding itself out when warm, which caused the long cranking times.

Jay

[Revenelson]

Originally Posted by 010175

.I have a 1999 with a 5.7 and it was doing the same thing. I did the presser gage test first. It would not hold fuel presser. Replaced fuel pressure regulator and fix the problem. You might try -search this site- for more help

I tried the pressure guage test this week. It will hold pressure for a while (62 psi) then go down to 20psi after being off for half an hour. I already replaced the fuel pressure regulator, so unless it is defective, I need to try something else. Thanks for the input.

[Revenelson]

Originally Posted by mxz600

Mine did the same thing and when the manifold leak was repaired, it was found to have a bad check valve on an injector. It dripped fuel when the key was turned on so it would start fine when cold and basically almost be flooding itself out when warm, which caused the long cranking times.

Jay

Thanks for the input. I think my problem started last year and I have more than one bad injector now. Instead of just fixing one or two, I'm replacing them all !! I will probably do what a friend suggested and pull them all out still attached and turn the fuel pump on and see which ones are leaking. If it is obvious which ones are leaking and which ones aren't, I will keep the good ones for future repairs.

I'll let everyone know how it turns out this weekend!