hesitation before 3000 rpm, awesome after

Simple88GT

New Member
Mar 19, 2008
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F-V, NC
when ever I take off from a stop, and just ease on the throttle the car just hesitates to go, it pops backfires and just plain wont go. It almost feels as if it is loading up on fuel. However once it hits 3000 rpm it picks up as if nothing were wrong. Also if I floor it from a stop it takes off like I would expect it to.

I pulled the codes and I get 33 41 and 91

I cannot find out what is causing the lean conditions I have checked the voltages on the O2s the were within the specified ranges, and searched for vac leaks using the brake cleaner method and didnt find any leaks.

the 33 is because the guy i bought the car from disconnected EVERYTHING that is smog related, so I am slowly getting the egr stuff back on.

Any help would be greatly appreciated

Thanks

Josh
 
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timing ist set at 14* and I checked the voltages at the computer i averaged .44 and .43

Could having the EGR blocked off at the head and intake cause a lean condition, when the Holley intake was put on we used the spacer to block the egr valve that was included with the gasket kit, since he didnt have the egr hooked up he felt it wasnt necessary.

Thanks

Josh
 
I am figuring it is a vac leak somewhere, or the intake plenum gasket needs to be replaced cause he reused that also and it was just the paper one not the metal core one that I will be buying to replace it

it was koer

koeo is all the smog stuff
 
Unplug the 02 sensors see if it is still doing it then. This has happened to me twice and once to a buddy each time we went through everything and it turned out to be the 02 sensors. After 3k rpm the computer doesnt read them anymore.
 
when I bought the car it didnt have O2's in it, and it ran perfect no hiccups or anything, I guess I should have just let it be, but I couldnt stand the smell of gas all the time. I just put the O2's in back in may of last year. It has been doing it since I put them in. I don't see way though. I have also upgraded to Maf since I bought the car in hopes it would help with the hesitation and running rich.

Thanks for the input


Josh
 
I know its been a while since the last post just wanted to update.

I unplugged the O2's and the problem has gone away. Could it be because I have Longtubes? I just cannot wrap my head around why this thing will not run properly with the O2's hooked up.

Thanks


-Josh-
 
I know its been a while since the last post just wanted to update.

I unplugged the O2's and the problem has gone away. Could it be because I have Longtubes? I just cannot wrap my head around why this thing will not run properly with the O2's hooked up.

Thanks


-Josh-
Wow that is weird.

C&L notes a different MAF for standard 5.0's (93 vs 94)

http://www.cnlperformance.com/calibration.html

Do the error codes go away with them unplugged?



Custom computer chip? :scratch:
 
No the codes are still present, and they are both brand new, and they both replaced new ones. Basically there were new ones in the car and the guy I bought the car from took them out because it was having this same problem, so when I bought the car I put 2 new O2's back in, and it started the hesitation problem again. With the O2's in it feels like it loses 100 horsepower under 3000 rpm, without the O2's it will run sub-8 seconds in the 1/8th I just don't understand.