Thread: Problem cant figure it out!! HELP!! LONG!

so a couple of weeks ago i had to put new heads on the car. Found out that the other set of heads i had on were junk.. I got the car put back together took it for the maiden voyage and it ran great. I went to turn around after about 10 miles and it started chugging like it was starving for fuel then i heard my walbro whine.. so i shut it down and called a friend and he brought me some gas put 5 gallons in it and it fired right up.. So there i thought well i must have a stuck float because the gauge is off from sitting. That seems to not be the case. for some reason now i cant run it past 1/4 tank without it wanting to buck and surge. ive heard of guys having problems with the fuel pumps not sucking all the way down so.. it gets worse.. now any time im under a load it seems to want to buck surge like its losing power.. i checked coils they check out within spec. ive got new plugs and msd wires.. i replaced the fuel filter which i couldnt hardly blow through.. the plugs are on the lighter shade of tan almost to the point i know its a little lean. could this be the fuel pump going out? the only code it throws it p0300 code which is mutiple things. ive changed the tps unit also. sunday night i drove to a friends house about an hour away and i was just about there when the car just died at a light the idle started going irratic and just puked.. Took about 10 mins and it fired back up i got over to his place and he is the one i bought the car from. he checked my vaccum lines out and i had some of those messed up check this out.. vacuum diagram for the l67 - FullThrottleV6.com -- The V6 Tech Source

so i didnt realize i had a 99 supercharger on the car for starters and i had the lines routed like a 97 would.. the 97 has a evap switch and the 98 and up doesnt.. do i need that? i now have the lines routed the best i can figure out from both diagrams for what i have on the car. I know im throwing a lot at you guys but this is really frustrating me.. im thinking its a fuel pump issue but i dont know for sure.. i dont have access to a fuel pressure gauge or else i would try that. i just know from what it feels like and what the plugs look like it might be the pump? if anyone else can help me out with this give me some kindof an idea what i should do that would be awsome thanks

i dont and i know i need to get it to zzp or someone with the correct programmer to get this figured out it would be the smartest thing but i hate to get it strapped up to the dyno again to just find out something else needs to be replaced ie: the heads lol.. im just going by the seat of the pants feel right now.. like i said it only surges under a load so to me thats a fuel problem..

well it ended up being the hose that goes from the pump to the top of the canister split.. changed that out and all is good now..

Originally Posted by iwinagn

well it ended up being the hose that goes from the pump to the top of the canister split.. changed that out and all is good now..

Glad to hear.

well i might have spoke to soon. the problem is better.. im gonna hook up a fuel pressure gage today to make sure its keeping fuel pressure. It still has an intermident feeling of surge going up hills and if i kick it down a little bit more it goes away.. Maybe its just me but it just feels like it is wanting more fuel.. I also was out last night and i noticed that if i decelerte from say 50mph and stay out of the gas the rpm's drop faster then the speedo and it will drop to around 800 rpms then jump up to 1200-1500 till it slows the rest of the way down.. im just gonna have to suck up some money i think and go get on the dyno and see what its doing. if anyone else can help me out here figure this out id be a very happy camper thanks!!

UPDATE: well i bought a fuel pressure gauge and at idle its a 50psi blip the throttle it goes up just a tad. Took it for a spin wot the gauge goes to 70psi. Now when it starts to act up it seems to be a 1/4 pedal the engine just seems to go flat and stays at a constant speed but the tach will go all over the place and i see by the boost gauge (stock) that it is almost full bars and this is at 1/4 throttle as well. So something is acting out on me if anyone has any clue that would be awsome.. I leading towards a faulty tps unit or maf. I just replaced the tps not more then 3 weeks ago.. But that isnt to say it couldnt have already taken a poop since i bought it at autozone.. I hope someone can give me some insight here as to what this thing is doing..

and the saga continues.. found a guy with a snap on scanner as we were thinking it was maf.. i got a maf from a friend at the local parts store to try. Put it in and it runs worse. scanned it and its getting a 0.00 value so either i have a wiring problem or the last guy to have a tuner on it turned the maf off. im at a loss here as the problem seems to be getting worse. what would you guys suggest?

honestly, IM not real good with this but if i were in ur shoes, guess i'd pay the GM mechanic, we have some really good GM mod mechanics around in my area.
costly though

yeah im waiting for a call back from zzp right now.. this car has me scratching my head.. problem is its my one and only car right now.. i cant afford for it to be down.

ouch. thats gotta hurt. u should keep a lil GEO around or somthing