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Discussion Starter · #1 ·
Well today i decided to install my new walbro 255 pump. I got it all installed fine and i went for a drive. The car stays rich but hesitates like crazy. I mean the whole car like shakes and then the power starts to hit. It only does it when i hold the throttle at wot, when i hold it a little and let boost and revs build up slower it rarely does it. if i am in like 3rd and hold it after all the major hesitations go away there are still minor ones. I adjusted my FPR to a low psi of pressure but no change. During the install i did everything to spec. The only thing i did different was the wires i connected straight to pump assebly where the stock ones were. I cant think of anything. I looked for vacuum leaks and even regapped my plugs down to 32. But still no change. If you guys can help me out that would be great. Any suggestions are greatly appriciated.
 

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sounds to me like a case of bad spark plug wires
 

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Discussion Starter · #3 ·
well i was thinking that it might be. i even replaced one with my stock one. they are all ngk ones and fairly new. The only odd thing is that it started to do this right after the pump. I am not sure how it could be wires if it only did it after the pump. I mean when it hesitates it goes a little inot stoich from a few bars in rich.
 

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If the car was running well before the pump I would assume that it's new pump that's the problem. Sounds like you could be flooding, causing it to bog and hesitate.
 

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sleepermx6 said:
this could be do to the whole controversy of adams chip not being remapped for more fuel, thus causing you to flood out, im not sure but that is my guese.please adam no ofense intended.
What? If the chip was not remapped for fuel he would run lean, not flood out. I think you have it backwards. adam's chip does not have a remapped curve. Look at a dyno plot, (theres a lot out there) the fuel curve is stock.

Nevertheless, the pump may or may not be the problem. The regulator will return extra fuel to the tank which leads me to believe it's not the pump. However, you cant be certain. I say swap back in the stock pump, even though i know you probably dont want to do that, then see if the problem goes away. A pump is easy to swap.
 

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rebel sorry you may be right but the walbro doesnt supply the car with the same amount of fuel as the stock, it supplies more right, or is that just under boost that it supplies more fuel which is where he is having his problems. im aware that adam doesnt have a remap of the fuel curve(read my original post to reference), which without the pump turning the boost up causes the car to run lean without extra fuel, therefore adding the pump would help to richen it a bit under boost correct by dumping more fuel into the mixture but since the chip was not remapped it doesnt know how much to dump so it's sending to much and flooding. if im wrong then im sorry and just ignore every thing ive said, but another thingis i dont care about some damn dyno plot that's been reposted by who knows how many people already, nough said on my part.
 

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sleepermx6 said:
rebel sorry you may be right but the walbro doesnt supply the car with the same amount of fuel as the stock, it supplies more right, or is that just under boost that it supplies more fuel which is where he is having his problems. im aware that adam doesnt have a remap of the fuel curve(read my original post to reference), which without the pump turning the boost up causes the car to run lean without extra fuel, therefore adding the pump would help to richen it a bit under boost correct by dumping more fuel into the mixture but since the chip was not remapped it doesnt know how much to dump so it's sending to much and flooding. if im wrong then im sorry and just ignore every thing ive said, but another thingis i dont care about some damn dyno plot that's been reposted by who knows how many people already, nough said on my part.
Well, I have a 190lph. I've had it with the stock chip and the zombie chip. The pump at normal boost is no different than stock. The only advantage would be at very high boost where higher fuel pressures or an FMU are added. I've hooked up a fuel pressure gauge and under boost at 15 psi, it would hover around 50 psi of fuel pressure. Also, idle pressure was a 36 psi. Same for walbro or stock.
The stock regulator is only set up with a diaphragm for about a 1:1 ratio. Therefore for every one psi of boost, fuel pressure will be increased 1 psi. The spring in the regulator sets the base fuel pressure. Sometimes it has been reported with a 255 lph pump that the pump will flow enough to make it overcome the spring and raise the fuel pressure to around 40-45 psi at idle. I have never heard such reports of this on 190 lph pumps.
I made a rising rate regulator with my stock one ( I wont go into details right now) but I had 70 psi at 10 psi of boost at one time. It didn't hesitate or anything even though it was running that rich. Also, at that boost level, the stock chip pins it pig rich. Still, no problems.
 

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Discussion Starter · #10 ·
well i am going to put my old pump in. I have played around with the sard fmu so i am not sure if its that. If it works fine with the old pump what would it mean ? that the pump is messed or something else ? thanks for all the good info. i will keep you posted. I am starting on the pump now.
 

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if you have a fmu hooked up, take it off before you do the fuel pump that helped me and i know zombiess will say teh same because that is the same thing my car was doing, exactly teh same, just ask zombiess he should remember, it was less than a month ago.
 

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Time for someone to do the AFM mod. I had to do that with my car on a upgraded turbo. Its now starting to run a little lean. I now have it so that its running slightly rich, once i adjusted the AFM i noticed that my idle was lumpy again. Before it would idle smooth and have no blurps
Ive noticed that my Walbro is screaming pretty high. This happend to my friends car, he then found out that someone had put sugar in his gas tank. I guess i should take a look at my fuel pump filter.
 

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Discussion Starter · #13 ·
well, i got it working. We took the pump out and basically ONly, and i must say ONLY took the electrical connector off the pump and put it back on and then changed the angle of the sock like 4 deg. and put it in the car and now its running fine. Its running rich even when the boost spikes to like 18. I havent had a chance to learn this EBC yet because i cant make it hold a set psi. If anarchy can help me with that it would be great. Thanks for the help guys. It seems that this was just some messed up case. Now i am going to the track this friday and i will see if i can hit 13s. I put those spring raisers and its done wonders for my car. No more needless spinning, i can actually get the power to the ground and i am wait to pick up a zombie chip so i can dyno it. I would have love to swap the zombie and adam chip on the dyno but i have sold my old chip and it will be out before then.
 

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Discussion Starter · #14 ·
well, not this is messed. I was driving from school and it started to do the same ****. At first faintly and now its making ht ecar jerk like crazy and i start chirping tires. thats how bad its hesitating. Now i am not sure if it is pump related. Maybe wires. I am not too sure. anyone have any guesses ?thanks
 

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Discussion Starter · #16 ·
so did u guys figure out why it wont work with a fmu ? i mean i have already payed for the fmu and i dont want to get rid of it if i can bypass the problem. Its odd. Its not like i dont believe you, its just i dont like to waste money and if so i would love to find out before i do. I will try to take the fmu off today and see if it helps.
 

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Discussion Starter · #17 ·
well sleepermx6, you and zombie were right. Today i bypassed my sard FMU and it seems to be working fine now with no hesitation. Thanks for the help guys. There is a slight problem though. it seems that now i cant boost past 15 psi, or my a/f gauge starts to read stoich and then lean. So it seems that even with the 255 pump i still am not getting enough fuel. My take on this is that without the FMU i dont have enough pressure and when i have the FMU install with adams chip i am most likely running too rich around the 5-7 psi mark. I have tested and it seems that this is the range i get the hesitation. No matter which gear. My idea is that with the chip it is making it too rich at that point. Now i am not sure what to do. i will try to test another chip this weekend. BTW zombie how fast can u send me a chip ? If someone can clearify this for me that would help. Thanks in advance.
 

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now that the car is running good, you'll need a chip such as zombiess to install in the your ecu, the good thing about his chip is that it's remapped for more fuel at higher boost levels so the car wont run lean, under normal boost, sorry cruising i'll experience a a/f between lean and stoickh , but as soon as i hammer the gas the meter flows to sotich and rich, big difference in how the car runs.
 

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Discussion Starter · #19 ·
ya i think i will order his chip. Just one question, even with his chip you still cant run the FMU ? i mean right now its like 1 bar rich at WOT and 15 psi. With the FMU i was like 3 bars rich at like 18 psi when it spiked. I would love to try to get the FMU and the pump to work. I mean there has to be a way.
 

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sorry there is really no way easy i know of except teh stock pump and a fmu possibly, with zombiess chip there is no need of an fmu since he remaps the fuel curve for more boost on his chip, we want the cars to acttually run a little rich on this car to insure the car is getting more than enough fuel for the added air being shoved into the motor
 
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