363whp stock block h22a...random fuel pump cut out

[rossisalvage]

Hey guys I just got my turbo project wrapped up and put some pretty sick numbers down for a stock motor. It runs great, but randomly, usually after driving for awhile or idleing for awhile it will shut down. If i got to restart, I don't hear the fuel pump prime up. If I take the key out and let it sit for 2-5min the pump will prime and it will fire up great and run great for awhile. It is defiently stalling because its not getting fuel. Its a walboro 255 pump, brand new. And I just replaced the main relay also. Any ideas? thanks in advance....

[toycar]

Hey guys I just got my turbo project wrapped up and put some pretty sick numbers down for a stock motor. It runs great, but randomly, usually after driving for awhile or idleing for awhile it will shut down. If i got to restart, I don't hear the fuel pump prime up. If I take the key out and let it sit for 2-5min the pump will prime and it will fire up great and run great for awhile. It is defiently stalling because its not getting fuel. Its a walboro 255 pump, brand new. And I just replaced the main relay also. Any ideas? thanks in advance....

Do you have a log of your runs? Im thinking it should throw a code as it dies with no fuel. Did it throw a code?

You could be running out of pump, but I doubt that.

What injectors are you using? What else can you tell me about your setup?

Fuel cuts usually happen at high RPM's under lots of boost. If your boosting without it cutting, its not the pump. Maybe the way the pump is wired is the issue. How did you wire it in?

[rossisalvage]

It dosen't throw a code at all when it dies, just gradually shuts off very smoothly. Im running 880cc precision injectors, and he said towards 340whp it started to lean out like it was starving for fuel, a mechanical issue he said. Injectors were at around %60 duty cycle even at 320whp which is said isnt right. I crimped the wires on the walboro pump, red to the power, black to ground. t3/t40e 60 trim, 11psi, custom top mount, srt4 stage 3 intercooler, 70mm tb, skunk2 intake mani, greddy type s bov, walboro 255, precision 880s, hondata s300.

[rexload]

- Is your new main relay brand new and OEM?
- "Crimped the fuel pump wires" ? I thought Walbro is plug-n-play, no crimping required. You sure the wires didn't come loose?

[toycar]

It dosen't throw a code at all when it dies, just gradually shuts off very smoothly. Im running 880cc precision injectors, and he said towards 340whp it started to lean out like it was starving for fuel, a mechanical issue he said. Injectors were at around %60 duty cycle even at 320whp which is said isnt right. I crimped the wires on the walboro pump, red to the power, black to ground. t3/t40e 60 trim, 11psi, custom top mount, srt4 stage 3 intercooler, 70mm tb, skunk2 intake mani, greddy type s bov, walboro 255, precision 880s, hondata s300.

Has nothing to do with the pump if its dying while idling.

I dunno, 60% duty seems like you possible have injectors too big for your setup-I know its hard to say they are too big, I guess a better way to say it is other injectors may suit your setup better. Is it running rich when it dies at idle? I am wondering how good your tuner is, if they werent able to straighten this out for you. This isnt that big of a problem, and certainly isnt related to the pump-not at those levels. Walbro 255's have made close to 600whp on DSM's a few times, 500whp plenty(thats the bench mark for starting to have issues) and 400whp is laughable with that fuel pump-not even stressing it out or anything.

Whats the start up like? Can you tune at all, or are you paying someone?

I hate to say it man, I think its in your tune. The closed loop cycle particularly.

Did you get a 255lph or a 255 high pressure pump?
Either one should be fine for these power levels, people make 400whp on the walbro 190. The 255 is a beast.

For reference, High pressure is way better on a build making this sorta power, you will just need to get an adjustable fuel pressure regulator. I would get a rising rate FPR if it was me. They can see boost, and raise the pressure accordingly. It takes a little finessing to get it right, but basically it will alow more pressure under higher vacuum(boost), and less as needed. This will help fine tune the duty cycles on the injectors under boost.

High pressure pump with no FPR is a bad idea and will cause you to run rich most of the time and make tuning a pita, thats why so many people use the 255lph pump with an OEM regulator. Stock FPR is decent, but at these power levels you need a better regulator.

As far as it dying under idle, again-not related to the pump. I would guess its running way too rich under idle(closed loop), and making the car die.
Is there any smoke or anything coming out of the exhaust? Do you have a logger?

I can help you get this straightened out, but I highly doubt its related to your fuel pump, especially if your not pushing the pressure any higher then 11psi. If its starving for fuel, why doesnt he increase the duty cycle? The reason I asked how you wired it, is you can re-wire the pump to get it down to 2 ohms, and squeeze a little extra out of the pump, but alot of people do it wrong and try to do this mod for no reason at all. Not your case.


If your pump was the issue, it would fuel cut under boost, probably around 5-6,000 rpms. And if your lucky your passenger wouldnt shoot out the windsheild from the herky jerky action of a fuel cut

(joke, nobody is getting tossed out of the car, it just jerks so hard its crazy)

[rossisalvage]

- Is your new main relay brand new and OEM?
- "Crimped the fuel pump wires" ? I thought Walbro is plug-n-play, no crimping required. You sure the wires didn't come loose?

Main relay is brand new oem aftermarket, but even the connections on the stock one look great, and it only has 100k on it.
Walbro comes with the install kit that you need to run the ground wire to the original ground spot on the braket, and connect the power wire to the stock power wire.

- Has nothing to do with the pump if its dying while idling.

I dunno, 60% duty seems like you possible have injectors too big for your setup-I know its hard to say they are too big, I guess a better way to say it is other injectors may suit your setup better. Is it running rich when it dies at idle? I am wondering how good your tuner is, if they werent able to straighten this out for you. This isnt that big of a problem, and certainly isnt related to the pump-not at those levels. Walbro 255's have made close to 600whp on DSM's a few times, 500whp plenty(thats the bench mark for starting to have issues) and 400whp is laughable with that fuel pump-not even stressing it out or anything.

Whats the start up like? Can you tune at all, or are you paying someone?

I hate to say it man, I think its in your tune. The closed loop cycle particularly.

Did you get a 255lph or a 255 high pressure pump?
Either one should be fine for these power levels, people make 400whp on the walbro 190. The 255 is a beast.

For reference, High pressure is way better on a build making this sorta power, you will just need to get an adjustable fuel pressure regulator. I would get a rising rate FPR if it was me. They can see boost, and raise the pressure accordingly. It takes a little finessing to get it right, but basically it will alow more pressure under higher vacuum(boost), and less as needed. This will help fine tune the duty cycles on the injectors under boost.

High pressure pump with no FPR is a bad idea and will cause you to run rich most of the time and make tuning a pita, thats why so many people use the 255lph pump with an OEM regulator. Stock FPR is decent, but at these power levels you need a better regulator.

As far as it dying under idle, again-not related to the pump. I would guess its running way too rich under idle(closed loop), and making the car die.
Is there any smoke or anything coming out of the exhaust? Do you have a logger?

I can help you get this straightened out, but I highly doubt its related to your fuel pump, especially if your not pushing the pressure any higher then 11psi. If its starving for fuel, why doesnt he increase the duty cycle? The reason I asked how you wired it, is you can re-wire the pump to get it down to 2 ohms, and squeeze a little extra out of the pump, but alot of people do it wrong and try to do this mod for no reason at all. Not your case.


If your pump was the issue, it would fuel cut under boost, probably around 5-6,000 rpms. And if your lucky your passenger wouldnt shoot out the windsheild from the herky jerky action of a fuel cut

(joke, nobody is getting tossed out of the car, it just jerks so hard its crazy?

Sometimes it will die not at an idle. Like today it died at 3,000 rpm while driving. The rpms slowly went to zero, over about 2 seconds. I was pumping the gas but it was almost like my throttle cable wasn't connected. I pulled over, 2 clicks of the key and the fuel pump wasn't priming. Sat for 2 min, tried 2 clicks it primed and started up. Drove home for 15 min fine.

The injectors might be too big, put I've seen people running these 880's on n/a h22's and stock h22's without an issue if the tune is right. Im not sure if its rich at idle, im gonna datalog it and throw in my a/f gauge. But if it was dying cause it was rich, why wouldnt the pump prime??? My tuner is one of the best in the area..... so I don't know. Starts up great, I can datalog but Im not too good at tuning.

Pump is the 255lph im pretty sure... I bought it from a member here, he said it was brand new and it looked new. There is no smoke comming out the exhaust, it runs real smooth. Im stumped.

[rossisalvage]

Heres my 344 run at 11 psi n retarded timing. I mean hes a good tuner I don't know



Uploaded with ImageShack.us

[Ghetto_CB7]

What software

What is your tuning setup, and if you can get a log of what is happening it would make diagnosing a lot easier.

It could be so many things without having a cal file and logs it is hard to tell.

You could have fluctuating battery voltage causing messed up injector durations, especially if the tuner did not tune for or at least find the correct battery offsets for the injectors.

If you were stock I would go with main relay as well, but with all thats been done it is hard to tell without a log / cal file.

[Raf99]

I'm no pro, but it almost looks like you've hit the maximum load efficiency for your setup. *shrugs*. I have no idea..., but i'm curious now.

[rossisalvage]

What is your tuning setup, and if you can get a log of what is happening it would make diagnosing a lot easier.

It could be so many things without having a cal file and logs it is hard to tell.

You could have fluctuating battery voltage causing messed up injector durations, especially if the tuner did not tune for or at least find the correct battery offsets for the injectors.

If you were stock I would go with main relay as well, but with all thats been done it is hard to tell without a log / cal file.

Im tuned on hondata s300. I will get a log asap. I am not as worried about the duty cycle as I am the pump randomly shutting off and not priming up. The car runs great and smooth when the pump is on.....its only when it shuts off then wont prime up for 3 min.
What do you guys think about this possible problems? This is just suggestions people have thrown out there..
1. fuel filter
2. Main relay-replaced
3. Wiring problem from wire harness
4. Faulty fuel pump with too much resistance, gets hot, shuts off then cools. or knock off walbro
5.Bad ground from esp alternator relocation kit?
6. Kinked fuel line
7. Bad ecu
8. Deleting the black charcol canister...

Let me know what you guys are thinking so I can start buying parts. Ill try and get a log as soon as possible also

[Skeet Skeet]

Does it do it at a certain level of gas? I had an Integra that did something similar to this at around half a tank. It would cut off and wouldn't prime right. The sock was actually fucked up and waaayyyy too short.

[Boost_Lee]

Hard to say

I don't think you are running too large of an injector. I run a walbro with 1000cc's, no issues. Doubting the main relay also since it was replaced, but a quick swap of the original unit can rule it out. Charcoal canister/alt ground, doubt it would cause this issue also.

I say verify your fuel pressure at idle first, since this does not happen under load. Make sure the vac line is good to the FPR also. After that check the wiring at the injectors and pump, and lastly check the pump itself and the pickup filter. thats my guess

[rossisalvage]

Does it do it at a certain level of gas? I had an Integra that did something similar to this at around half a tank. It would cut off and wouldn't prime right. The sock was actually fucked up and waaayyyy too short.

Nah it dosen't seem to do it at a certain level, it only did it once on the dyno, at 3/4 a tank. Now that it is under half a tank it is doing it more often, but I dont know if thats related to the fuel level or driving it on the street.

Hard to say

I don't think you are running too large of an injector. I run a walbro with 1000cc's, no issues. Doubting the main relay also since it was replaced, but a quick swap of the original unit can rule it out. Charcoal canister/alt ground, doubt it would cause this issue also.

I say verify your fuel pressure at idle first, since this does not happen under load. Make sure the vac line is good to the FPR also. After that check the wiring at the injectors and pump, and lastly check the pump itself and the pickup filter. thats my guess

I agree man, Ive seen plenty of people run the walbro with 1000cc's no problem. I swapped back to the original main relay and still the same issue. It did happen at 3 thousand rpms yesterday, and 2 thousand. When it does, the car slowly stalls out. Its not like the rpms drop off, it gradually decreases down to 0, and yesterday even stopped at 1,000 and idled for about a sec before dying. I try pumping the throttle in the peroid that it is dying but it does nothing, kinda like the cable isnt even connected. Thanks for the help everyone! ill be checking all them things

[92smokeaccord]

did u recheck the ground for the actual fuel pump....did u make a new ground spot for the pump or did u use a existing ground spot that was in the car already?if u did make a new spot and sand the hell out of it and ues a self tapping screw..same thing was happing to me when i had my old h22 turbo with the same pump...used a ground spot that was on the car keep stalling out,made new ground like stated above and ran fine after that....

[rossisalvage]

did u recheck the ground for the actual fuel pump....did u make a new ground spot for the pump or did u use a existing ground spot that was in the car already?if u did make a new spot and sand the hell out of it and ues a self tapping screw..same thing was happing to me when i had my old h22 turbo with the same pump...used a ground spot that was on the car keep stalling out,made new ground like stated above and ran fine after that....

are you talking about the ground on the bracket that the acutal pump is on? I used the original ground hole and original screw..... maybe it is alittle loose?