Kylem12

Just installed a new drivetrain from the motor back to rear end in my 99 corvettes. After debugging all the ground issues I had the car finally started. It idled for at least 45 minutes to an hour and did not miss a beat. The next day it started right up so I shut it off and finalized the rest of the install and I went to go take it for the first test drive and it started to sputter like it was starving for fuel before I even made it out the driveway. Back into the shop, we went and I could hear the fuel pump kicking on for 2-3 seconds when I turned the key on so I thought the pump was bad. Luckily I had preordered the Lingenfelter 600hp rated fuel pump. So I installed that thinking it was the problem and it was not. Checked the relay and its good. The fuel pump will run but it will not build up enough pressure in the rails barely any fuel comes out of the shader valve. Has around 1/4 tank. The car was sitting roughly for 8-10 months with 1/2 a tank of 93 octanes in it. Every now and then it'll try to start but sputter out. Almost like there is a blockage somewhere. Any help would be really appreciated.

Vetteman Jack

Moved to C5 Tech.

Bill Curlee

IF,,, the pump runs at KEY ON (for the 1-3 sec prime) and does not buid up pressure, (ARE YOU SURE that you have enough fuel in the tank)????

Kylem12

Hello Bill,
I am Almost positive there is enough fuel in that tank. When I rook The fuel pump out I must Have lost close to 5-6 gallons. I then Replaced that with another 5 gallon when I finished the install

Kylem12

When I replaced The pump on the driver side, the fuel float as attached to the pump. So I’m guessing that the fuel gauge woul read out of that tank. But I could be wrong. I was Thinking that maybe the pressure regulator went bad. Because she ran good the day before and when I finished putting her back together (exhaust and hood) she idled for another 15 minutes but when I went To leave the drive way it started to act up. So I parked her back in the garage and Called it a night. When I went Back in the morning before work she started right up and I let Her idle for 30 seconds roughly. But when I got Home all she did was spit and sputter and tried to start

Kylem12

That is why I’ve decided to come to the forum for help. I’ve already put an additional 5 gallons into the tank after the fuel pump install, pump does come on but still no pressure on the lines. Even if I juno It out at the relay. It has a little more pressure that way but not much more. That’s why I was Trying to narrow it down to the next simple fix which I thoght Was the regulator within the filter. I’ve checked all lines and no leaks

69

Here are a few tips in troubleshooting



(1) Fuel Feed Pipe
(2) Fuel Feed Rear Pipe Check Valve
(3) Fuel Feed Rear Crossover Pipe (left tank to jet pump)
(4) Fuel Sender Fuel Feed Pipe (jet pump to left tank)
(5) Fuel Feed Rear Pipe (with check valve)
(6) Fuel Return Rear Pipe
(7) Fuel Sender Fuel Feed Pipe (jet pump to left tank)
(8) Fuel Filter/Fuel Pressure Regulator

Visually and physically inspect the following items:
Did you find a problem in any of these areas?
• The fuel filter/fuel pressure regulator (8) for obstructions
• The fuel feed pipe (1) for a restriction
• The fuel pump strainer for obstruction

Cheers,
Goose

69

Another thought here>
When you stated you replaced the pump, can you clarify?
Did you replace the fuel pump module assembly which contains the pump, level sensor, pipes and wiring?
OR
Did you just replace the pump in the fuel module assembly?
What brand name parts did you use, AC Delco? Other?

Let us know, I will post up detailed trouble-shooting procedures this evening.
Goose

Kylem12

I just replaces the pump within the driver side tank. Removed the old “guys” so to say and installed the new ligenfelter pump rated for 600hp. The stock pump ran the engine for roughly 2 hours idle time combined but when I lowered The car down and went to go take it for its first test ride I didnt Make it out to the street before it was spitting and sputtering. Parked her back in the garage and she died. Wouldn’t start, every now and it would try with a little spit and sputter but no go. I had Already purchased the pump for this build so I decided we’ll maybe just maybe my pump doesn’t have enough oomph for the new injectors and motor so I went Ahead and change it out. Same problem when I crank. She will spit and sputter but no go. That’s what led me to thinking well the car sat for 8-10 months in my garage with all her drivetrain ripped out. I thought That maybe the 1/2 tank of gas went bad and caused a blockage within the fuel line or maybe the fuel filter is clogged or the regulator inside he filter isn’t opening to allow pressure to the rails. Both the old pump and new pump come on. Just very minimum pressure in the rails. Push the shader valve in and get maybe half a second of decent pressure then a trickle of fuel.

69

OK, Thanks for the info, After reviewing this thread, I’m not seeing any fuel pressure PSI numbers> It’s very important to troubleshoot using a fuel pressure gauge.



OK, let’s get you back on the road!

Way forward>

If you do not have a fuel pressure gauge, go to your “local HF tool store” and purchase the fuel pressure gage kit.

Which can quickly test the fuel pump pressure on most injector systems with this fuel injection pump tester. The tester's gauge reads 0-100 PSI, 0 to 7 bar. The fuel injection pump tester comes with flex hoses, fittings and instructions for quick reference.



Troubleshooting Steps;

Fuel System Leak-Down Check

Step 1) connect fuel pressure tester to the injector rail, cycle ignition key from “OFF to RUN” 1 time and verify you “hear” the fuel pump run for approx. 2 seconds. The fuel pump will only run for 2 seconds to pressurize fuel rail which is normal.

Next> verify you have NO fuel leaks at the fuel rail to pressure gauge connection. If you have any leaks correct immediately as is most important NOT to have any leaks for this test.

Next> Cycle ignition key from “OFF to RUN” listen for the fuel pump run for approx. 2 seconds. Do this ignition key cycling 5 times to build fuel pressure in the fuel rail.

Action> Record fuel pressure indicated on the pressure gauge and post your finding.?

Action> with pressure gauge still connected to the fuel rail and indicating pressure, wait 5 minutes and record fuel pressure on gauge and post up your findings.? This test is establishing fuel pressure “bleed down” rate of the system.



LPE provides great PDF instructions with photos for replacing the fuel pump at the following link. https://www.lingenfelter.com/product...l#.WilFfjOWyV0

Question> Did you use LPE PDF instructions to replace the pump?

Question> During the pump replacement did you replace the white convoluted plastic fuel line connected from the fuel pump to the top of the fuel module. This line is 375 MM and if original to the car, it can suffer from aging/fatigue issues and can be damaged/ruptured during fuel pump replacement.



Fuel Pump Pressure output test

To determine that the fuel pump is providing pressure and the white convoluted plastic fuel line connected from the fuel pump to the top of the fuel module is not damaged or ruptured, you will need to connect the fuel pressure gauge to the fuel pump module pressure OUT line.

Step 1) there are 3 pipes exiting the left fuel pump module, identify the main fuel pump pressure OUT line and disconnect line from fuel pump module.

Using a small piece of rubber hose and hose clamp, attach hose and clamp to the pump pressure OUT line. WARNING be careful not to damage to pipe on the fuel pump module while attaching this hose and clamp.

Next> Connect your fuel pressure gauge to this hose and secure hose with clamp.



Now that your fuel pressure gauge is plumed directly on the fuel pump, we will now understand what the pump is exactly putting out in way of fuel pressure.



Next> cycle ignition key from “OFF to RUN” 1 time and verify you “hear” the fuel pump run for approx. 2 seconds. verify you have NO fuel leaks!!!!!

If you have any leaks correct immediately as is most important NOT to have any fuel leaks for this test.

Next> Cycle ignition key from “OFF to RUN” listen for the fuel pump run for approx. 2 seconds.

Action> Record fuel pressure indicated on the gauge while the pump is running during the 2 second run burst (you may need an additional person to view the pressure gauge while the ignition key is cycled from “OFF to RUN” during this test). , post your findings.?



Post up you findings so we can get you back on the road!

Cheers,

Goose

Kylem12

Okay this is what I found Out, I went And purchased a snap-on fuel pressure gage and have 55-60 lbs of pressure in the rails at all times. From turning the key on to cranking it over. But the same problem is still here. I’m now thinking it’s no longer fuel related. I have No codes on the dic. I manage To get her to run briefly but I had To kinda peddle the car. It ran like crap. Sounded like it didn’t have all 8 cylinders firing. Checked all fuses and plugs and have spark to all. The motor is a 383 stroker lunati parts in. Everything is brand new inside the motor back to the tranny and gears. Injectors are 42 lbs Bosch. With the wiring harness adapter for the injectors.
Thank you for your time!

Kylem12

UPDATE:
I got the car running... finally. I decided To do a compression check and found after removing the plugs they were beyond fouled. Lest then 2 hours idle time on them but I’m assuming it’s from burning off all the excess break in and assembly lune I installed During the build process.
Only problem now is after finally being able to take the car out for its first 1/2 mike test run there was a lot of hesitation under a load. Almost like the car was trying to sputter out. Smells like it’s running rich as well. I know It needs a proper tuning and I was Hoping to break it in at least 500 miles first but there is no way I could Drive this car as it is now. Any thoughts on how I can Get this car to somewhat drive right till I dyno tune it?
Recap: sputters, loss of power, hesitation under throttle 1-3 gears, almost dying out, 4th gear through 6th still hesitation but drivable. 383 stroker, sns stage 3 cam from tick performance, billet transmission rated for 1000hp, 4.10 gears in the rear end.
thank you all for you help,
Kyle

neutron82

so does your pcm still have the old tune in it before you had all the current work done?... if so you either need to trailer the car to whoever is going to tune it, take the pcm to the tuner and have them write you a base file to get it running so you can drive it there or if you have access to hptuners they can send you a base file that you can load yourself and then take it to get tuned

Kylem12

I originally started with the cam from tickperformance and the 243 heads with bigger valves installed and ported with brt fuel springs and titanium retainers. Took it to redline motor sports and they tuned the car for the work that was completed to it. Low and behold ran for about two months and noticed while cruising I was Loosing oil pressure. **** her down immediately and brought her home and found slimmers of flake in the oil. Pulled the engine and found two partially spun rod bearings.

foggy

Agree with neutron..
Get that car to the tuner.. The bigger injectors are flooding out your new engine..
You may even be beyond the point that the rings will ever seal.
You've washed the new cylinder hone
Trailer it to the tuner... Get it initially tuned so you don't do more damage.
Then get some break in miles on it.. Then back to the tuner with new plugs - again.
Also,... Change your oil and filter NOW.. It'll be full of fuel.

neutron82

so the cam and heads are the same from the old setup that was tuned and you just changed out the rotating assembly?... if that's the case I think it should start up and run and be drivable but I would not romp on it obviously until you have it retuned... the issue must be somewhere else... do you have any idea if they tuned the car speed density?... just curious because if they did any misfire codes will not register and you will have to diagnose it manually... that may not be the case but just throwing out ideas

neutron82

I didn't catch that, if the injectors are new and you did not retune for them that could definitely be a problem

Kylem12

Car has less then 1/2 a mile drive time and under two miles idle time. Car sound amazing idling. No sputtering or massive rpm ramps. I’ve got a snap on reader and the idle rpms range from 800-900rpms. I dont think any damage has been done. I’ve seen many cars built that have way bigger stroke/injectors that have been broke in for 1000 miles on a stock tune. I swapped The heads and cam over and installed all new everything lol. Melling oil high pressure pump, 25% under drive, all new sensors, plugs, wires, only thing original is the coil packs. I dont See spending 400 plus on new coils when I’ve read they are paper mounts. I’ve checked the oil by draining a quart out and it looks brand new. No fuel or anything. Yes the old plugs were fouled and smelt like gas but the gas issue was due to the constant turning the engine over trying to figure out my problem and the multiple fuel injector tests I’ve ran over the week. Car is drivable 4th gear and up. I dont Know if I’m over reacting due to the bigger gears and injectors. I can Feel a massive amount of low end torque increase after them. With the original tune from redline I would As well think it should be safe to idle around. I have Zero intententions of romping on it. To much money invested to watch it go up in smoke. Been there done that twice now lmao

Kylem12

I forgot to add that I just Did a compression test on each cylinder and when cranking the psi was around 140-150 on each cylinder and after I stopped cranking the needle would go down to 120-130

Bill Curlee

Quick QUESTION....... DId you change the injectors to better larger ones????????????????????????????

Bill