1999 f-550 will not start when the motor gets warm. Starts cold but not as good as it used to

New injector control moduel

Injectors are just over a year old

new low pressure oil pump

new high pressure oil pump with new hoses

glow plugs are just over a year old as well.

320,000 miles with about 3,000 idle hours

Started up great a week ago, drove it and ran fine all day. Meet some friends at a restaurant and when I went back out to fire it up all it did is crank. If you give it a small shot of starting fluid (it was that or pay for a tow bill) it starts up right now and runs.

The only other thing that it has been doing odd before the no start is the RPM would go up and down by a few hundred at an idle.

I am out of ideas and it's getting expensive as you can tell. lol

 

Sounds as though you may have an IPR or Injector Seal Leaking. Next time its hot, try monitoring the below PID's.

echo=on
No Start / Hard Start / Cold / Warm

Tools: OBD-II On-Board Diagnostics, Phase 2 Vehicle Media Communications Unit (Scanner)

1. Select the parameters indicated from the Scan Tool parameter list and monitor while cranking engine.

Data List Monitoring Parameter:
V-PWR 10.5 VDC Minimum.
RPM 100 RPM Minimum (0 - CMP Suspect)
ICP 500 PSI or 3.4 MPAM Minimum
ICPv (KOEO) Spec 0.20v - 0.30v
FUEL PW: 1 MS - 6 MS ( <1 / >6 IDM Suspect)
V-PWR - If indicating a low voltage condition, check battery voltage, charging system or power and ground circuits to the PCM.
DC% - Cranking NTE 20% / 65% is Closed. (IPR Suspect)

2. RPM - Low RPM could be an indication of starting/ charging system problems

3. No RPM indicated with the engine cranking - could be CMP circuit fault, check for DTC’s.

4. ICP - A minimum of 500 PSI (3.4 mPa) is required before the injectors are enabled. No or low oil in the reservoir, system leakage, injector O-Rings, or faulty IPR could cause pressure loss.
Note: If no RPM signal is received, IPR duty cycle will default to 14%

5. FUEL PW - Even though a 1 to 6 mS FUEL PW is shown, it’s possible the IDM did not receive the signal due to a CI or FDCS circuit fault or internal IDM failure.
echo=off

FWIW: If you think that Tow bill would have set you back, That starting fluid will set you back up to $5,000 if it combusts on its exhaust stroke and breaks a Rod. Disconnect the Glow Plugs when using Starter Fluid!

 

My oil pressure is 500 and seems to hold. Also had a compression test done and it passed as well.

I understand about the starting fluid. Guess you can call it frustration and aggravation.

 

500 psig is just enough to get it running. You can see upwards of 3,000 lbs. when under load with a DC% as high as 65%.

Almost always, a "Hot No Start" is Oil Related delivery to the HEUI System.

 

Is it an early 99 or late 99 by build date?

Where did the IDM come from.

 

If you can monitor the ICP and IPR duty cycle that would help a lot. Also check the tin nut on the back of the IPR make sure it's snug. And the ICP sensor harness for oil in the connection. If the IPR is holding pressure when cold but failing when hot, the Redneck Rescue is a Big Gulp of ice poured on it, allow to cool for 5 - 10 minutes, see if she starts.

 

As of right now I haven't had time to fool with it.

It's starting to get a little rough to start in the mornings. It's only been 40 degrees, it had been starting great.

As soon as I get time I'll work on it and update what I find.

Thanks for all the ideas and input.