96z28_lt1

like the title says, i recently got the car together after a cam/head swap

the vehicle was untuned and i had overtightened the rockers fixed that car fired up only by giving it WOT in which case it reved freely but as soon as i let off the gas to let it idle... bam it died. Now when i go to start it under WOT it can start sometimes only holding at like 500-600 rpms and then i re adjusted valves again and it start under WOT again reved up to about 2000rpm i let off the gas it died again. did it again to show a buddy what it was doing at which point it revved up to about 4500 and stopped i then let off the gas and it died out like normally but i can keep it running if i stay on the throttle but its not a healthy running....

at one point i know it was geting too much fuel because i put 36lb/hr injectors in, swapped out stock injectors and changed plugs to keep it from flooding anymore, there is fuel in the oil but i'm waiting till it runs to change it out for incase there is something else causing the problem

i deleted smog air egr have block off plates, got rid of my ac, wasn't sure if any of this could be a reason i know its finicky about sensors.

mods are
comp cams 280xfi 230/236 113lsa
longtube headers, off road y
professional products throttle body
le2 heads
1.6 rr
new opti, waterpump
had 36lb/hr fuel injectors on 4 bar system, swapped out for stock injectors

unhooked battery a few times to see if it would restart the computer, i'm at a loss now... could my tps be off it shows .8 volts closed

Guest47904

WOT starting cuts off the injectors called clear flood mode. Do a vacuum check of the FPR on the vacuum port and lift the fuel rails and pressurize it to see if any injectors are leaking.

Check your oil for fuel contamination also.

If all that is done and you still have a problem, check compression. You may have damaged some cylinders.

96z28_lt1

also my obd2 code reader when i plug it in it use to turn on and scan the car, now it won't even turn on so i can't scan for codes, i tested the code reader on my other vehicle and it still works.... wondering if there might be something wrong with the computer even though they rarley fail in these cars

96z28_lt1

oil has contamination in it from when the 36lb injectors were plugged in i have the oil and filter have not changed it yet for if is still leaking fuel i don't wanna have to keep changing the oil

Injuneer

Check the fuse for the cigarette lighter. That's where the power to the ALDL connector comes from.

96z28_lt1

ALDL, i'll check it imma check the injectors to just for ease of mind, just curious what aldl is

96z28_lt1

fuse is blown for the aldl which is for the obd scanner right, just wasn't sure what it stood for

96z28_lt1

through a po100 code mass airflow sensor gonna check the wiring real quick and go to autozone pick up new fuel filter and see if they got a more elaborate scanner mine only gives codes no readings

96z28_lt1

pink wire on mass air flow sensor has 11.7 volts also which would be battery voltage right? Any other ideas anyone wanna spit out to me imma jump on this hard tomorrow and give it a go i deleted the mass air code and it re read and came back again deleted it again and now it won't show back up imma try to run it a little tomorrow and see if it spits anymore codes because i'm not even getting codes for all the emissions stuff i took off

Injuneer

If you have 11.7V, did you measure it from the pink wire to the black/white wire in the harness connector? If so, you have verified both the 12V and ground wires. That leave a faulty MAF sensor or the connection to the yellow signal wire. At idle, if your multi-meter has a frequency scale, see if you have about 2,600Hz on the yellow wire (measure to ground).

I'd really like to help more, but your posts are getting harder to understand with no punctuation and all the "immas".

bubba4

Also check engine coolant temp sensor,(with code scanner) for correct temp, that will give alot of trouble if it is bad. My tps likes .58 to .62 vdc feed back at closed and around 30-35 steps on the iac at idle in park. I had to modify the tps bolt holes to get those numbers and adjust the blade stop.

96z28_lt1

sorry injuneer grammar was never a strong subject for me. When i measured the pink wire it was 11.7 to a ground on the car and not the ground wire itself i will go out and re check this though. Tryed giving it a start today with vaccuum line off of the fpr and only got stumbles with and without throttle and an occasional loud backfire from the exhaust. I'll probably end up biting the bullet and just go out and buy me a better reader on it that tells me the levels today since it will be a good future reference tool for me anyways. The car has sat since last august so i was thinking maybe bad fuel would explain the horrible starts up i've been having but i'm just not sure. I know that WOT starts is a clear flood mode, and i still have to check the injectors to make sure they are not leaking but they weren't leaking when i ripped the car apart back in august and have just been sitting in the house so maybe those could possible have some gummed up fuel in them.... but thanks everyoe for the replies i tryed making this post a little easier to understand hope it helps

96z28_lt1

i'll also add that both coolant temp sensors have been replaced

Injuneer

Have you actually driven it on the street? Some of the codes don't even run the diagnostics until the engine is actually operating under load, fully warmed up, etc..

cyteone

I have an extra OEM MAF for a LT1 camaro that works perfectly.
I'd be willing to sell it for $35 shipped. Pm me if you're interested.