Good News & Bad News

Good News:
she finally moved under her own power.

Bad News:
when in gear(under a load), i stomp the gas & she bogs down, backfires & falls on her face. put it in neutral & i can rev the crap out of her.

i bought a fuel pressure gauge & when i turn the key the pressure builds to about 12 psi. start the truck & it slowly goes up to 57-59, cheap harbor freight needle jumps around.
when i hit the throttle she revs fine but the pressure drops to 20-30 PSI.
no check engine light, so i'm thinking the fuel pump?

congrats and condolences! lol.. def sounds like ti could be the fuel pump. good luck to u man. any news on the radiator covers?

I had a similar problem. In neutral would rev but once in drive fall on its face. It was the fuel pump

If your staying NA walboro 255 if there's plans for fi aeromotive 340. Either are cheaper than factory replacement .... btw been following your truck in fb, looks gteat and need to get with you bout one if those bad Ass hats!

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Originally Posted by myzterray

congrats and condolences! lol.. def sounds like ti could be the fuel pump. good luck to u man. any news on the radiator covers?

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i'm working on them. i have the measurements just need to get out to the shop to route & brake them. i was hoping to do them this week but don't know if i'm going to make it out there since my truck isn't running right.

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Originally Posted by RPM Graphics

i'm working on them. i have the measurements just need to get out to the shop to route & brake them. i was hoping to do them this week but don't know if i'm going to make it out there since my truck isn't running right.

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cool cool! cant wait bro.

fix the fuel problem. one of my lines was restricted. unfortunately it still runs rough. i pulled the plug on my MAF to see if it would throw a code & turn on the LED check engine light but it never came on. we put a reader on it & there was a code for the MAF. no other codes but we could see the MAP was at 10.8 in park & jumped to 14 when i put it in gear. i was told it should be around 5. when it's in gear it runs really rough now. it's not throwing a code for the MAP so i was told to check for vacuum leak around the intake & MAP. we'll see what happens tomorrow.

right under the MAP sensor is a small vacuum port. where does that go, or can i cap it?
right now it's just open so i think that may be my problem.

Cap it!

capped it this morning. seams to run better but i haven't had a chance to go drive it yet. crossing my fingers that's my problem.

test drove it & still runs bad. not sure what to do now. i'm trying to find a better scan tool to see if we can get some more info.

What's the fuel pressure at now?

get a laser temp gun and go shoot your exhaust looking for cylinders cold or much hotter than others. You may have a clogged injector. An injector balance test could be done. You could have a bad plug, plug wire, coil, injector or who knows what else.

fuel pressure at the rail is now 58-60 psi. i sent the injectors off during the swap & had them bench cleaned & flow tested. they said everything looked great, flowed & tested perfect. plug wires & plugs are new, along with the O2 sensors. i'll probably pull the plugs & see how they look tomorrow, weather permitting. i think i really need someone to plug into it & see what's really going on.

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Originally Posted by RPM Graphics

fuel pressure at the rail is now 58-60 psi. i sent the injectors off during the swap & had them bench cleaned & flow tested. they said everything looked great, flowed & tested perfect. plug wires & plugs are new, along with the O2 sensors. i'll probably pull the plugs & see how they look tomorrow, weather permitting. i think i really need someone to plug into it & see what's really going on.

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Where do you live?

New Orleans area.

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Originally Posted by RPM Graphics

New Orleans area.

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Well, I am in the Dallas area. If your were closer I could help.

yeah, i know a bunch of people in TX that can help, but no one close to me.

just hooked up my tach & noticed it doesn't move till i'm at about 3-4k. think something could be wrong with my tune?

What year model tune is in the pcm? One year in paticular has an issue with dri ing a tachomer and you have to put a resistor inline with it to make it function properly.

the PCM is the one that came with the motor/trans., from an 02 camaro. it has a Nelson tune. funny thing is the check engine light, LED on the Nelson harness, doesn't come on either. i unplug the MAF to see if it would throw a code & no light, but when we plugged in the code reader there was a code for the MAF. not sure if that would be in the harness or ECU/PCM.

driver side plugs are completely covered in a dry black carbon. cleaned them up, put them back in & drove around the block. still running bad & in the short drive the plugs are covered again. like the driver side coils aren't getting the right signal or something. i'm going to switch the coils from the driver side to pass. side & see what happens. i don't think it will change but i don't know what else to do until i find a scan tool. someone also told me the Nelson harness won't communicate with Snap-On or Mac scanners. anyone else heard of this?

is there any exhaust leak prior to the o2 sensor? that would cause it to run pig rich on that bank...also how does it run with at WOT?

i think it does have a small leak where the header meets the head. the allen head bolts that came with the headers aren't worth a crap.
in park WOT she runs fine. once i put it in gear & drive down the block it starts to run rough, sputtering & missing.

the exhaust leak will cause it to run rich becuase the o2 sensor reads it as being lean when its really not and dumps the fuel to it...At WOT it will run fine becuase the pcm doesnt use the o2 sensors for fueling at WOT. Unplug both o2 sensors and see how it runs then....it should stay in open loop and run fine if im guessing correctly :)

found the problem. 2 of the wires on the harness going to the drivers side O2 sensor were crossed. swapped them around & everything looks good on the scan tool. hopefully i'll have some time this evening to go test drive it.

Awesome! Congrats bro hope it screams! How do I go about ordering one if your bad ass hats?

ahh i knew it was something to do with the o2 sensor :) glad to hear you got it straightend out!!

yea, my friend came over with his mac daddy scan tool. we could see the driver side was acting crazy. swapped the O2's around & it was doing the same thing. he was checking the O2 plugs & we noticed the wires were in different locations. swapped the driver side to match the passenger side & everything looked great on the scan tool. i'm off to a field trip with my daughter right now but hopefully i'll be roasting some tires this evening!!!!:burnout:

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Originally Posted by jansen

Awesome! Congrats bro hope it screams! How do I go about ordering one if your bad ass hats?

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LMK what you want & we can go from there.

Glad to hear its thats much closer to being done! It's one killer build you have going.