FUEL PRESSURE DROP
#1 _JNR_ATE_
Posted 20 July 2006 - 01:08 AM
Its a new fuel pump, rebuilt quaddy, any ideas. how quick should it drop off it at all?
Cheers
JNR_ATE
#2 _devilsadvocate_
Posted 20 July 2006 - 06:33 AM
#3 _JNR_ATE_
Posted 20 July 2006 - 08:21 PM
I noticed that if i drive for a while get it hot then switch it off for 20 mins or so. i try to start it after and it cranks and cranks and wont fire, like its building the fuel pressure back up, or its just flooded because it splutters and i need to keep cranking till she fires properly,
Only mainly wen its hot or just been driven, if i park it then try to start 10 hours later after work in the cold night, bang straight away.
Im lost
Cheers
JNR_ATE
#4
Posted 21 July 2006 - 01:02 PM
Is it a mechanical pump?
#5 _JNR_ATE_
Posted 22 July 2006 - 12:47 AM
Current steel fuel lines are the standard and run neatly away from the extractors.
Cheers
JNR_ATE
#6
Posted 22 July 2006 - 09:59 AM
It could still be heat soak.. I used to get this in my 202 torana cause i removed the heat shield from under teh carby and it used to heat soak and be a real bitch till the temps came right out of the carby itself! ( Ages!)...
maybe your insulation is working... it may be keeping the heat IN the fuel line rather than out of it? can you feel the carby area/fuel inlet line to see if its hot when this problem is occuring?
The only other thing i could think of is if the pump has some kind of fracture that opens up when hot releasing pressure.... have you got a relacement pump you could try?
Good luck mate!
#7 _JNR_ATE_
Posted 22 July 2006 - 05:08 PM
The fuel pressure guage is between pump and carby obviously and sits around 6 Psi when the problem occurs, there is fuel pressure according to the guage but seems to crank and crank and splutters when its trying to start.
But like you said with your 202, leave it 10hours between work and it starts first go, maybe a short plastic spreadbore carby spacer to suit performer to quaddy might help?
I dont have a new pump to try, maybe an electric one might be the go, lol
Whats the best option with Elec fuel pumps,?
Cheers
JNR_ATE
#8 _devilsadvocate_
Posted 22 July 2006 - 07:38 PM
Your starting prob sounds does sound like vapor lock, to try and pinpoint the source-pour cold water on lines(they will be cooler inside the insulation).....if makes no difference try and rapidly cool area just around float bowel with fan or water spray.
#9 _JNR_ATE_
Posted 23 July 2006 - 02:12 AM
Sounds dodgy Steel hose, insulated fuel hose, fuel pump, steel hose, fuel hose with guage in-line then fuel hose into the carby.
Pictures might be better
I just cant see why it would be vapour lock if the guage reads 6 Psi, 6 inches before it enters the carby.
Cheers
JNR_ATE
#10 _devilsadvocate_
Posted 23 July 2006 - 02:47 AM
#11
Posted 23 July 2006 - 02:21 PM
#12 _JNR_ATE_
Posted 23 July 2006 - 08:02 PM
I would hope its not stuffed because the carby was rebuilt and jetted before the engine was started.
If the needle and seat were in trouble, could this cause bad fuel economy aswell?
Cheers
JNR_ATE
#13 _jimjet61_
Posted 24 July 2006 - 11:57 AM
#14 _JNR_ATE_
Posted 24 July 2006 - 01:25 PM
Think i need it dyno tuned?
Yeah its an early model type rochy and my valve stem seal are fine,
Like i said, do they make spreadbore carby spacers to suit performer to quaddy that will eliminate the heat soak?
Cheers
JNR_ATE
#15 _jap-xu1_
Posted 01 August 2006 - 09:36 PM
This would make for bad hot starts but when its cold it would love that extra fuel on startup
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