rielcrazy

Hi, recently my car stoped working, it was intermitent at first, shutting off randomly and throwing codes. Fule pressure was all over the place. I replaced the fuel pump, but no go. I borrowed a scanner and got codes P0102 and P0506. One is for MAF and the other is Inatke air control valve. The car has cam/intake, and has been tuned by frost, but this issue started months after I did all that. I'm not sure what the acv is but i know what maf is.

Anyone recommend next step to diagnosing? Will one also cause the other? Again, it cranks and cranks, got fuel, but no start.

Thanks

FSTR/TA

iTrader: (49)

Make sure everything aroung the throttle body is plugged in correctly. The IAC or Idle Air Control Valve is what lets air in at idle. Without air, your car will not start! Two screws hold it in, remove it and clean it. Possible it needs replacing. The MAF could be same thing, check plug! Could also be contaminated with oil from a K&N or such oiled filter. Clean with MAF cleaner! Hope this helps your fix.

rielcrazy

took iacv out to clean it and it fell apart. However, before I did this I tried to start it with the throttle slightly depressed which should open the tb and let air and fuel in so it shoudl run atleast somewhat. It won't even kickover. I will be ordering a new iacv but I'm not sure that's the issue, going to borrow a maf from a buddy and see if that fixes it but again I would think if those were the issue it would atleast run to some degree or try to fire. It just turns with no kick at all. I would think that a crank sensor or ignition control module would atleast throw a code if it was that so i'm kinda stumped.

fireburr

iTrader: (3)

I have had this problem occur with my ls1 swap trans am. I am running a speed density tune to maf to deal with. I found an extremely strong vaccum on the oil fill tube. It will run for about 5 minutes until it warms up, then surge a couple times, then die and won't start. I found if I leave the oil cap off it will idle a little high and surge a little but wont die. Not sure if this is the same problem you guys are having but I am still looking for the answer too. After I shut the engine off it sounds like it's taking its last long dying breath from a strong vaccum like its starving for air. I'm going to check my iac valve tonight and see if this cures the problem.

rielcrazy

Fireburr do you have a pcv valve or breathers? You shouldn't be getting super high vacuum in your crankcase.

Anyway, that was not my problem. My problem was..... drumroll........ ignition relay... how lame is that? For some reason I figured the relay was ok because it was turning over, of course there is a starter relay though, not sure why I didn't think of it first. I had like 4 guys who know their SH** working on it with me so I don't feel toooooo stupid. Randomly came across it in an obscure reference to a similar problem somewhere on the internet after hours of searching and whala. Anyway, hope this helps someone.

tt383lt1

iTrader: (3)

the ignition control module is built into every coil so thats not it. can you check for crank and cam singals? with no spark on all 8 cylinders it cant be plug, plug wire, ignition module. i would check the crank and cam singals and all the fuses and relays for the coils and when you said you have fuel is that pessure at the rails or coming out of the injectors?