Hard Starting When Hot

E

EAFMan

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Joined
Feb 25, 2008
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28
Just completed my new engine. Starts great when cool/cold. Once it heats up then it has to crank for a minute. Doesn't matter how long I wait it has to crank. Any ideas?
 
I beleive that is a symptom of a failing VP.

Are you showing any codes by either doing the 3 turn with the key or with a scan tool?
 
No Codes. Brand New VP. 53 miles on it. I hope it is not that. Will call supplier in the morning. It is a hrvp however.
 
Usually that's a VP but there's one other thing it could be but I can't remember.
 
16 psi. Use FASS. I will check it with a seperate guage when I get home tonight and verify. I did pick up a companion code (1653?) so I will try to get that scanned at the dealer if they will do it without flashing the ECM. Is there a scan tool that will read the engine codes in case the dealer won't?
 
If you are going to head for the dealer there is a TSB on the hard start issues, lemme do some digging and see if I can't find it.
 
Fuel pressure right on 16 psi.
I really don't want to go to the dealer, so I had the 1693 code cleared. It has not come back. Still doesn't start when hot.
Called Pump Supplier, immediatley offered me a warrantee exchange. Started talking about the "PSG" in the pump saying that when the fuel gets hot, viscosity drops and the pump can't deliver enough pressure to overcome the pop-off pressure of the injectors at cranking rpms. Although I have no idea what a psg is the scenario makes sense to me as I get no smoke (white, grey or other) when trying to start it when its hot.
Billysgoat if you find the TSB I am still interested. Thanks

FYI, When it does start, this thing runs better than my expectations.
 
EAFMan said:
Fuel pressure right on 16 psi.
I really don't want to go to the dealer, so I had the 1693 code cleared. It has not come back. Still doesn't start when hot.
Called Pump Supplier, immediatley offered me a warrantee exchange. Started talking about the "PSG" in the pump saying that when the fuel gets hot, viscosity drops and the pump can't deliver enough pressure to overcome the pop-off pressure of the injectors at cranking rpms. Although I have no idea what a psg is the scenario makes sense to me as I get no smoke (white, grey or other) when trying to start it when its hot.
Billysgoat if you find the TSB I am still interested. Thanks

FYI, When it does start, this thing runs better than my expectations.
Click to expand...


You can try flashing with a Smarty (if you dont already have one)...this will update your ECM. AND has been known to fix this issue.

OR

You could do this
 
Billysgoat said:
If you are going to head for the dealer there is a TSB on the hard start issues, lemme do some digging and see if I can't find it.
Click to expand...

i believe the up date was for the L/P and the amount of time it runs with the key on (not started).....5 seconds or so...compared to 20 sec.
 
Graphic Man said:
i believe the up date was for the L/P and the amount of time it runs with the key on (not started).....5 seconds or so...compared to 20 sec.
Click to expand...

I got to looking through Fritz's site and found that particular TSB, but there was another on that addressed hard starts when hot. That or my CRS is really kicking up, as I get time I'll keep looking though.
 
New pump sitting by the door when I got home today. Will try to install it tommorrow.

I don't have a smarty or know anyone locally that does unfortunatey. Not sure what route I will take in the future.
 
Last edited:
Slap the new pump on and see what happens, go from there cuz it sounds like the fella you bought it from knows his stuff.
 
Replaced pump last night. Starts perfectly so far. Even hot. Will watch it the next few days and see if it continues to start as easily.
Engine sounds and acts different too. Little more ping and snap to it.

Can't wait to put it on a dyno.
 
Hopefully you found the problem and nipped it right then!

Let us know how it dynos.
 
EAFMan said:
Replaced pump last night. Starts perfectly so far. Even hot. Will watch it the next few days and see if it continues to start as easily.
Engine sounds and acts different too. Little more ping and snap to it.

Can't wait to put it on a dyno.
Click to expand...



Good deal!
 
I started having hard hot starts this summer. I relate it to my fuel system that brings up the pressure as soon as I start cranking. I was really frustrated a couple of times, as it took 5-6 attempts to start the engine. In the end, I popped the hood and drained some fuel from the filter and... started with half a crank!
I think I may re-wire the LP to a circuit that is not energized when cranking.
-P
 
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