525EFI Warm start problem - ??
Platinum Member
09-30-2014, 03:18 PM
#22
wybmabilty hit it spot on with hot soak flood condition. I've had this happen as well thinking it was vapor lock. It is NOT vapor lock. Motor is flooded pure and simple. How it happens depends. The injector issues addressed are one possibility. Depending on the fuel system, pump configuration and plumbing there are some times vent lines that vent vapors into the manifold causing the same condition. I know this happens on VST equipped motors and is often mistaken for vapor lock.
09-30-2014, 05:21 PM
#23
It absolutely does. Beyond opening the TB blades and allowing more air in readings from the TPS cause the ECM to go into flood clear mode which shuts off the injector drivers so no more fuel is added.
wybmabilty hit it spot on with hot soak flood condition. I've had this happen as well thinking it was vapor lock. It is NOT vapor lock. Motor is flooded pure and simple. How it happens depends. The injector issues addressed are one possibility. Depending on the fuel system, pump configuration and plumbing there are some times vent lines that vent vapors into the manifold causing the same condition. I know this happens on VST equipped motors and is often mistaken for vapor lock.
wybmabilty hit it spot on with hot soak flood condition. I've had this happen as well thinking it was vapor lock. It is NOT vapor lock. Motor is flooded pure and simple. How it happens depends. The injector issues addressed are one possibility. Depending on the fuel system, pump configuration and plumbing there are some times vent lines that vent vapors into the manifold causing the same condition. I know this happens on VST equipped motors and is often mistaken for vapor lock.
09-30-2014, 07:51 PM
#25
Registered
iTrader: (1)
Those that didn't, won't tell me what they use. Damn it. Makes it hard to find other vendors that will have issues or not.
BTW: we all know gasoline is flammable, therefore injectors won't typically be sent with fuel in them, thus why other fluids.
09-30-2014, 09:27 PM
#26
Registered
iTrader: (30)
Put a new short block in one of my engines last year swapped all necessary parts
525 efi motors also ..in the heat exchanger there is a temp sender somehow in between pulling the old motor and rigging the new motor it went bad .. I could start the motor cold and if I let it run any more than 10 min it would not restart again unless I waited an hr or so .. If I held throttle wide open( clear flood mode ) it would restart after a lot of cranking .. Turns out temp sensor was the only issue .. Motor simply thought it was cold and dumps more fuel even when warm ..they have a new design temp switch .. Early ones were all plastic the replacement is brass. ..u have to remove heat exchanger to get at it
525 efi motors also ..in the heat exchanger there is a temp sender somehow in between pulling the old motor and rigging the new motor it went bad .. I could start the motor cold and if I let it run any more than 10 min it would not restart again unless I waited an hr or so .. If I held throttle wide open( clear flood mode ) it would restart after a lot of cranking .. Turns out temp sensor was the only issue .. Motor simply thought it was cold and dumps more fuel even when warm ..they have a new design temp switch .. Early ones were all plastic the replacement is brass. ..u have to remove heat exchanger to get at it
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JanTore (03-06-2023)
09-30-2014, 09:46 PM
#27
Put a new short block in one of my engines last year swapped all necessary parts
525 efi motors also ..in the heat exchanger there is a temp sender somehow in between pulling the old motor and rigging the new motor it went bad .. I could start the motor cold and if I let it run any more than 10 min it would not restart again unless I waited an hr or so .. If I held throttle wide open( clear flood mode ) it would restart after a lot of cranking .. Turns out temp sensor was the only issue .. Motor simply thought it was cold and dumps more fuel even when warm ..they have a new design temp switch .. Early ones were all plastic the replacement is brass. ..u have to remove heat exchanger to get at it
525 efi motors also ..in the heat exchanger there is a temp sender somehow in between pulling the old motor and rigging the new motor it went bad .. I could start the motor cold and if I let it run any more than 10 min it would not restart again unless I waited an hr or so .. If I held throttle wide open( clear flood mode ) it would restart after a lot of cranking .. Turns out temp sensor was the only issue .. Motor simply thought it was cold and dumps more fuel even when warm ..they have a new design temp switch .. Early ones were all plastic the replacement is brass. ..u have to remove heat exchanger to get at it
10-01-2014, 07:41 AM
#29
Put a new short block in one of my engines last year swapped all necessary parts
525 efi motors also ..in the heat exchanger there is a temp sender somehow in between pulling the old motor and rigging the new motor it went bad .. I could start the motor cold and if I let it run any more than 10 min it would not restart again unless I waited an hr or so .. If I held throttle wide open( clear flood mode ) it would restart after a lot of cranking .. Turns out temp sensor was the only issue .. Motor simply thought it was cold and dumps more fuel even when warm ..they have a new design temp switch .. Early ones were all plastic the replacement is brass. ..u have to remove heat exchanger to get at it
525 efi motors also ..in the heat exchanger there is a temp sender somehow in between pulling the old motor and rigging the new motor it went bad .. I could start the motor cold and if I let it run any more than 10 min it would not restart again unless I waited an hr or so .. If I held throttle wide open( clear flood mode ) it would restart after a lot of cranking .. Turns out temp sensor was the only issue .. Motor simply thought it was cold and dumps more fuel even when warm ..they have a new design temp switch .. Early ones were all plastic the replacement is brass. ..u have to remove heat exchanger to get at it
[ATTACH=CONFIG]530194[/ATTACH]
http://www.mercruiserparts.com/Show_...tem+Components
10-18-2014, 07:32 AM
#30
I had the same problem with the engine yesterday... cold start fired right up... ran her for 15 minutes, let sit for 2 hours and it took me 4 turns of the key to get her to fire.. I hooked up a fuel pressure tester yesterday to test the leaky injector theory. Got around 40 psi at idle and it took over 2 hours for the pressure to bleed down to around 16 psi and then I let the pressure out manually. I would think that if the injectors were leaking, the pressure would bleed off much faster than that. I think I will try to replace the temp sensor on the chance that Smokin Gun's theory is right, but any other ideas?
