7845

iTrader: (1)

lets see im having 2 issues and i cant figure them out. first one is my fuel keeps bleeding down. my fuel system consists of..... 2 walboros intank using -6 to a Y block then -8 to a checkvalve to a inline filter then to the speed inc fuel rails. i crossover at front of motor and goes into my Magnafuel regulator [2k hp model] then returns with -6. im using motron 60s. now at idle my fuel psi is right at 55 and 58 at 0 vaccum. now my problem with fuel is i cycle key and i build pressure and lose it as fast as i build it. now if i hurry up and start truck and then use throttle i can get it to run and idle. now if i cycle key and dont react fast enough truck wont start for a few more tries and when it does i ahve to have throttle 100% and then im excessively rich. this doesntmatter if im warmd up or not. my commanded AFR can be 14.7 and still have rich condition after this happens. if i catch it on first cycle of key its fine. my oil is soaked with fuel. today i removed plugs and dissconnected the harness from injectors. i ohm'd injectors and they read 12 ohms. i also cycled the key and installed a plug in 1 cylinder and i noticed some fuel on the threads of the plug. i did other cylinders and didnt notice any on the threads. i wiped the threads clean did it again and got little more on the threads............any ideas on the fuel issue? i was thinking of installing a set of stock injectors into truck to see if pressure stays


other issue is this...... other day was out logging and working on tune and motor accidently spiked to 25psi at 50% throttle, i instantly let off throttle. little later i went for a another log after i made some changes to tune. it hit 19psi at wot in first and i broke the rear end. well i get everything fixed a few days later and i go to drive it and i notice my truck from time to time drops 1in of vaccum and starts to idle funny. it then goes away. well i pull truck in and do a compression check. it reads from 140 to 147 across the board. no oil in coolant no coolant in oil. no coolant on fenders or anything. oil psi still good. also plugs looked good. i pul my fast and notice the floor of it where it had been repaired was cracked again. i guess the spike blew apart the epoxy on the intake's floor. so i swapped to the ls2 intake i had laying around. started truck up had 10in of vaccum. as it warmed up i lost vaccum to 9 again. im still scratching my head on this. well i figured out why i overspiked. Tial 60mm gate springs are rated wrong. installed the 5 psi spring and im seeing 8psi. ok this is livable. so i go out and start tuning again for this intake. first thing i notice truck is rich but with the ported fast tune was spot on at 14.7 for out of boost. i also notice my right bank and left bank was opposite. one was calling for fuel other was trying to lean out. so truck wasnt happy with running out of boost. the W02 read richer then target. i drove some more and logs keep looking rich, no matter how much fuel i pulled i was still rich according to W02. i did get into boost for a short time and seemed fine once inboost after this truck the truck started to idle badly and only at 3in of vaccum. i pulled plugs and did comp test all checked out fine again. motor doesnt smoke, no oil in coolant or coolant in oil. motor isnt noisey, still have good oil psi.. i went to start it yesterday after taking days off and i got it to run again and had to use throttle and had no vaccum this time. today i pulled plugs oncei got truck home and plugs were soaked in fuel. can the vaccum be related to a fuel issue? or soemthing else?


setup is 02 silverado 4.8 with 241 heads. 8.8cr , 230/236 115lsa, PT88, Tial 60mm. when it first was running it would idle with 10in of vaccum. the drop to 9in doesnt make sense but that happend after the motor spiked to 25 then to 19. the 19 was WOT and since has been giving me issues


thanks and sorry for long post but i have no more patience and cant seem to figure this out

OUTLAWZ RACING

iTrader: (9)

Fuel set up sounds like mine. But I have a regulator on the rail. My idle psi is set at 45 boost hits it goes to 60 psi. My fuel drains fast like that too. But my builder says every car he has done did that. I dont have a issue with it at all. But it sounds to me that the regulator is not feeding properly and causing excessive fuel to go into the motor. By the way you did remove the stock FPR out the tank right?

7845

iTrader: (1)

my stock regulator was on the fuel rail. think 97-98 vette here. i did the regulator as i seen on here and also have the diagram shows. my regulator is o the rail but is on the back of driverside. the fuel is getting into motor and it shouldnt. the injectors to me should hold the pressure and not drip. i have a noticable amount of gas in my oil.

ls1290

iTrader: (20)

Not good. Sound like the PCM is not setup correctly for the 60# injectors and they are pissing fuel. I would not run the car anymore until the calibration of the injectors in the PCM is correct. It is not good to wash the cylinder walls down with fuel. Doing that will damage the rings and prevent them from making a good seal with the cylinder wall. This is led to lots of blow by, bad compression, and the need of a rebuild.

7845

iTrader: (1)

the tune for the injectors is fine. my AFR when running properly is right at 14.7. fuel trims are right on within +-5. my issue is within holding of the pressure. truck doesnt have tobe running to have he bleed down. the harness is off injectors and im still having bleed down. going to swap injectors and see if that is the main issue

stevieturbo

With engine off, and fuel pump off, my fuel system pressure drops to around zero.


I dont see it as a problem....your problem sounds more like a tuning issue.

On initial key on, the pump will prime for a few seconds, and if the engine is rotating, the pump will also work.
So I dont see why it should cause any starting problems.

The fact you say you are having to go WOT to get the thing started, is very wrong.

7845

iTrader: (1)

well i believe i found alot of my issues. first thing i noticed. i pulled my old injectors and yes a few were dripping. these i bought off ebay claimed 60lbers... they ohm'd out to be 12 for a reading. so i borrowed a set of 42s for now. they ohm out to be 16 these are bascially brand new. i installed these and didnt see any drips. but pressure did drop again. when i took rail off i noticed i still have fuel in the rail that the regulator was mounted to. well i went over entire feed and then took it part. i pulled filter apart and notice debris in the screen. i also notice some real small particles that might of went thru the screen. [might have clogged injectors]. well i cleaned filter and noticed the liquid i was pouring thru was coming out other side of my line. so i tore it part at the checkvalve. and noticed the flap didnt seem right. cleaned that and tested. yupp it leaks. tore it apart and tried again. again it leaks. it holds air one way but doesnt hold liquid. so my bleeding off is from the walboros and the earls check valve not working so i wasted money with this product. [over winter going ot make some changes now]

next issue to address. see if the spike hurt motor....

did a compression check and motor reads as follows
1=150 2=145
3=145 4=145
5=150 6=145
7=150 8=145
these were all done with a snap-on gauge

ok next test was a leak down. so i started pulling valve cover off to check for valves being bent again and good. as i noticed i pulled the booster line and i had vaccum on this [good sign]
so did a leak down and this motor is claimed to be a 7k mile motor

1=2% 2=1%
3=1% 4=1%
5=1% 6=2%
7=1% 8=1%

guess motor checks out. so tomorrow going to toss plugs back in and give it a try again. i believe my fuel issue was the bad injectors....least motor is sound