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View Full Version : 02 4.6 novi problems!!!!



INSANEBA
04-22-2008, 10:22 AM
Hi all, I am having trouble with this damn thing. It's an 02 gt, with a NOVI1000 supercharger on it. The problem is that it has smoked the last 3 motors it's had in it. I dont know what's going on, all I can figure is that it's lost it's tune from the ecm. It will run fine for a short while, then it will start knocking. I seem to think it's pre-detonation, like it's lost it's tune. The first motor had all probe forged internals, and it smashed a bearing bigger than sh!t. 2 motors later, here we are. Any help would be greatly appreciated, thanks in advance....:confused:

bobtsgt
04-22-2008, 10:42 AM
what size injectors and fuel pump is in the car? also what type of regulator and which MAF do you have in it? Are you still running the stock fuel computer in the back? Did you ever put it on the dyno to see where your A/F is or have a wideband?

INSANEBA
04-22-2008, 10:49 AM
what size injectors and fuel pump is in the car? also what type of regulator and which MAF do you have in it? Are you still running the stock fuel computer in the back? Did you ever put it on the dyno to see where your A/F is or have a wideband?

Hey Bob, the story on the car is that it was a wreck we re-built. As for the fuel pump, I know it's a walbro 255. As for the injectors and maf, I'm not sure. The car is my buddies, and I kept telling him that it needed to go to a "pro" shop to get the boost set-up correctly. As far as I can tell, the computer is stock, but I figured it was re-burnned to run the combo. After we put in this last motor, I told him he needed to get it on a dyno, to get it right, but he's young and didnt want to spend the money. Now that he needs another motor, he's finally willing to listen. I'm at the point that I really would like someone with alot of boost experience to go over the car and see if we are missing anything. Atleast go over it before we put another motor in it. Maybe this time it could last a little longer than a couple of weeks lol.

bobtsgt
04-22-2008, 11:40 AM
yeah if he was neglecting a proper tune and didn't have a wideband then he was askin for it. The computer I was referencing is located in the trunk that controls voltage to the pump. Does he even have a fuel gauge or a boost reference regulator? If he gets it back together he needs to take it somewhere and have it gone through and dyno tuned. Unless he likes putting motors in every couple of months. A good tune will save a motor.

INSANEBA
04-22-2008, 03:08 PM
LOL, yeah it's more like putting a motor in every weel or two lol. I just talked to Chris @ MD, and he kinda got me pointed in the right direction. I dont know about the fuel comp, I'll have to check it out. Is it basically like a boost-a-pump? My brother has one on his car. He finally agrees he has to get it right before a new motor goes in this time, besides he's goin for broke buying all theese motors to swap in. Thanks for your help, Bran...

bobtsgt
04-22-2008, 03:27 PM
Its a factory computer used to regulate the voltage so the pump isn't pumping full bore all the time. It increases voltage as needed. He may need a boost a pump if the pump is not putting out enough volts. In that case he will need to buy a modded fuel pump computer to handle the extra voltage.

mustanginky
04-22-2008, 06:54 PM
i would say that the walbro pump is a piece of shit. look on MD or modular powerhouse. read about that pump with a power adder. if it's the one that procharger sent out with the kit they quit sending it out b/c of these issues. what happens is that pump is designed for a return style fuel system, he has a returnless. it burns up or runs out of fuel.

what was he doing when the engine let go? hammering down hard? high load like not downshifting or something like that?

INSANEBA
04-22-2008, 11:00 PM
Actually, this time he was taking it easy. The last couple of times he ran it hard, and got the expected result. He's coming over tomorow, and were gonna go over it. Hopefully I can tell you more tomorow, I deffinitely think it's a pre detonation/lack of fuel problem. No one has taken the time to figure it out until now. I guess I'm the lucky one this time lol...
I'll check out part numbers on the pump tomorow, and maybe that will tell a little more. Thanks again guys...

mustanginky
04-23-2008, 10:23 PM
well i'm telling ya walbro never made a 255 pump that i'm aware of to work on a returnless system. so i'm betting that's the culprit. tell him this time around to get a svt focus pump (believe it or not it works great!!!) and he'll be happier. it only cost me like $80 when i bought it, but you might need to get with randy stinchomb about it and see what it'd cost him now.

Blackout
05-01-2008, 11:01 AM
yeah the walbro is a problem. Your car's pumps run is pulses. earlier cars ran on return systems and the pump could just keep running all the time.



It only cost me like $80 when i bought it, but you might need to get with randy stinchomb about it and see what it'd cost him now.

For $80 get me one and I will give you a $100.:bigthumb

05yellowgt
05-05-2008, 03:04 PM
Sounds like there is definitely something tune related or something mechanical with the fuel system setup going on. Just because a motor has a "bulletproof" bottom end doesn't make it bulletproof. I'd TOW the car to a shop and have it looked over before starting up the next motor you put into it and have them go over it with a fine toothed comb.

INSANEBA
05-13-2008, 06:59 PM
Yea, we're gonna take it to MD, and have them look it over with the bad motor. That way we have a parts list, and a decent starting tune too. Thanks for all the help guys, Brandon...