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OK, I smelt something fishy earlier today, and NO, its not my lunch.
This 1992 car MUST be a late 1992, towards 1993, with the 6ltr style fuel rail and stuff. Still a 5.3, but totally different to the earlier Twin FPR engines.
The fuel pipes, rear to front on this car are both on the LH side, from what I can see on the Parts Schematics. The fuel filter is behind the LHF wheel, where our earlier cars has the Atmospheric Coolant Tank.
The FPR is an encapsulated Mini FPR (GM style), attached directly to the RH (A) front of the squat fuel rail.
The system has a MYRIAD of sensors, solenoids, hoses, etc etc, for what the Part Schematics calls " Hot start system", and I would bet that somewhere in that myriad of plumbing lies the issue.
I have attached the Parts Pages, and links to the catalogue for each section.
OK, I smelt something fishy earlier today, and NO, its not my lunch.
This 1992 car MUST be a late 1992, towards 1993, with the 6ltr style fuel rail and stuff. Still a 5.3, but totally different to the earlier Twin FPR engines.
The fuel pipes, rear to front on this car are both on the LH side, from what I can see on the Parts Schematics. The fuel filter is behind the LHF wheel, where our earlier cars has the Atmospheric Coolant Tank.
The FPR is an encapsulated Mini FPR (GM style), attached directly to the RH (A) front of the squat fuel rail.
The system has a MYRIAD of sensors, solenoids, hoses, etc etc, for what the Part Schematics calls " Hot start system", and I would bet that somewhere in that myriad of plumbing lies the issue.
I have attached the Parts Pages, and links to the catalogue for each section.
Honestly, I would be thrilled to improve the hot start but still in my mind the fear I have that something else is intermittently hidden in there as I tried to describe in the original posting. Please keep the ideas coming! I will dig into this. Who knows, maybe I will decide I like this car after all and spend the rest of my days apologizing to it and taking on more improvements.
Bloody hell, don't do that. If a V12 even gets a sniff of fear, or an apology, YOU ARE DOOMED.
They know, they always know.
Strong suggestion from way down here.
The front Crank Sensor has been changed, TICK
The rear is the Original, and just as tired as the front one. The rear one gets HOTTER, and DIRTIER, so a new Crank Sensor REAR will do no harm, and eliminate it from any further suspicion.
They are a simply magnet thingy and get tired, BUT, as Greg has said, the gap when setting them up is critical. I have only ever seen ONE Marelli car, and that was a 6ltr, and I have NOT touched one ever, so specifics etc on gaps would be Warrens domain.
Not sure on Marelli cars, but spark plug GAP is CRITICAL on the Lucas cars, and even more so on our 12.5:1 comp ratio engines. I see NO reason the Marelli would be any less critical. I use 0.025" as a plug gap on all my V12's, exactly what teh book says.
Bloody hell, don't do that. If a V12 even gets a sniff of fear, or an apology, YOU ARE DOOMED.
They know, they always know.
Strong suggestion from way down here.
The front Crank Sensor has been changed, TICK
The rear is the Original, and just as tired as the front one. The rear one gets HOTTER, and DIRTIER, so a new Crank Sensor REAR will do no harm, and eliminate it from any further suspicion.
They are a simply magnet thingy and get tired, BUT, as Greg has said, the gap when setting them up is critical. I have only ever seen ONE Marelli car, and that was a 6ltr, and I have NOT touched one ever, so specifics etc on gaps would be Warrens domain.
Not sure on Marelli cars, but spark plug GAP is CRITICAL on the Lucas cars, and even more so on our 12.5:1 comp ratio engines. I see NO reason the Marelli would be any less critical. I use 0.025" as a plug gap on all my V12's, exactly what teh book says.
Grant, thank you for the strong suggestion. I will check the manual how to get to this sensor and if I can change it. Is this something that could be intermittent?
Spark plugs were changed first first thing when I got the car and the gap was checked on every one. I believe it was .25. Whatever the book said. I did this with another owner of the exact same car in his garage along with wires and rotor.
OK, first coffee is still attempting to do its magic.
When was the last time the throttle bodies were CLEANED. Our earlier cars built up "black death", and HOT start and idle suffered terribly. MMMMMM.
Simple:
Clean rag
Solvent, gasoline if all else fails to materialise.
Beer, FOR YOU.
Remove the air filters.
Open the throttles manually, engine OFF obviously, dont ask why I say that.
Soak that rag with the solvent, wipe all the goo out of the throttle body and the off the disc, both side. Keep at it until it looks like new.
Refit air cleaners.
Drink beer.
Start the beast.
This SHOULD be done at EVERY oil change.
Cost, almost ZERO.
Satisfaction, PRICELESS.
Last edited by Grant Francis; 02-08-2019 at 04:55 AM.
OK, first coffee is still attempting to do its magic.
When was the last time the throttle bodies were CLEANED. Our earlier cars built up "black death", and HOT start and idle suffered terribly. MMMMMM.
Simple:
Clean rag
Solvent, gasoline if all elsae fails to materialise.
Beer, FOR YOU.
Remove the air filters.
Open the throttles manually, engine OFF obviously, dont ask why I say that.
Soak that rag with the solvent, wipe all the goo out of the throttle body and the off the disc, both side. Keep at it until it looks like new.
Refit air cleaners.
Drink beer.
Start the beast.
This SHOULD be done at EVERY oil change.
Cost, almost ZERO.
Satisfaction, PRICELESS.
Excellent. I love an easy job that cost nothing and works wonders. As soon as I return to Miami this will be done.
Then to attack that hot start circuit, and further on to dig out that rear engine sensor.
Will continue to drive and enjoy as long as I can get it running.
HOWEVER, I ask all of you who care to re-read my initial post carefully. I am certainly interested in solving the routine hot start situation. But that is not the reason this post was created and I am pretty sure I will need to come back to the original concern at some point.
After cleaning the throttle body I don't "feel" much difference, but using the process described previously with the single accelerator pump it seems better. I think the idle is higher, though...
I'm now researching the hot start system as this seems to make seems as a place to look for improvement. So far I see the vacuum to the FPR is supposed to be shut off at fuel rail temp above 70 deg. C providing higher fuel pressure at start.
02-06-2019, 06:17 AM
