GN running great!!!! when it finally starts.....replaced gas tank with brand new one due to rust in the old tank, from sitting while the engine was rebuilt. Car was and is running great! However, when you turn the key on, fuel pressure at 20psi, as you hold the key and it tries to start, pressure slowly builds to 40psi and then it fires right up and runs great. This began after changing fuel tank. What to look at???? Where to begin troubleshooting? Fuel pump is obviously pumping....
Low Fuel Pressure until car finally starts????
- Thread starter tscruggs
- Start date
Tony serio
Member
- Joined
- Jun 22, 2014
Fuel pump all factory? What fuel mods? Any rust in the lines fuel filter clogged? And or injectors ? Need more info
Tony serio
Member
- Joined
- Jun 22, 2014
grounds tight?
Original fuel pump....brand new filter...no rust anywhere...adjustable pressure set at 42.....fuel inj are 50#?....yes...turn key to on pressure stays at 20....hold key as starting and the engine sputters while pressure builds...at 40# engine fires right up...just started after changing tank and filter
Jerryl, you are a straight awesome man to work with...if I can ever help you, please let me know...you got a place to stay if you are ever in southwest mississippi area....and yes the pressure builds as the car sputters until 40# then it fires right up and runs perfect
Tony serio
Member
- Joined
- Jun 22, 2014
Wonder if the pump crapped out on ya I've had things break just by lookin at em wrong lol I would start by double checking the install of the new tank if the problem didn't exists prior, have u checked the fuel pressure with an actual gauge hooked up to it ?, don't just trust the gauge on the rail I've had several liquid filled become inaccurate over time I know it will suck but I'd drop the tank again give it a once over gasket or line not kinked, connector or ground not seated or tight, look for anything obvious power /ground at pump if all that checks out inspect your fuel pump relay and fuse also, if that's okay and you said it's the original pump safe to say you probably got the life out of it , time for a performance upgrade
Last edited:
Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
Tscruggs, keep us posted. Try simple things first.
Run a wire bat+ to prime the pump from the connector at the ac, koeo, and see if the pressure increase behaves similar.
You may very well need to drop the tank again, and if you do, i can mail some parts for testing if that helps.
Some real knowledgeable guys in MS area that may be close.
Run a wire bat+ to prime the pump from the connector at the ac, koeo, and see if the pressure increase behaves similar.
You may very well need to drop the tank again, and if you do, i can mail some parts for testing if that helps.
Some real knowledgeable guys in MS area that may be close.
- Joined
- Feb 18, 2006
Sounds like it's starting on the oil pressure switch.
Does the fuel pump run for 2 seconds when key is turned on?
Does the fuel pump run for 2 seconds when key is turned on?
- Joined
- Aug 1, 2003
x2 what you desribe is a bad fp relay and pump is running on the oil pressure sender once oilpressure builds above 4psi , when you turn key on does pump run for a fewseconds , if not replace the fp relay on pass fender
Yes fuel pump runs but only pressures up to 20psi
Thank you jerryl! I think I will replace fp relay and change to walbro hot wired fuel pump....will update shortly
- Joined
- May 28, 2001
That's 1/2 of what it should be..."Original pump", and you are powering an engine w/ 50# injs???
Voltage at the pump is? Check both the + and - sides engine running.
Check resistance across all connections.
What Jerryl said:
Run a wire bat+ to prime the pump from the connector at the ac, koeo, and see if the pressure increase behaves similar.
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