Sorry if I posted this in the wrong spot , the prom board seemed to be more for the guys that burn thier own chips and not issues like this.

For starters I think I am reaching the limits of the stock chip . But I'm not understanding why I got some of the readings I got from my scan tool today at the strip . I thought as you add airflow improvements the car will get leaner at WOT without prom work . And in my case ( I have yet to touch the heads, runners or TB) raising the fuel pressure would compensate , I am right in saying that arent I??
The deal with my car is with the mods I have my car is running pig rich at WOT . At 48 psi 02 mv are 1000-1050 and if I take the psi down to 38 950 mv's is as good as it gets . Around town driving integrator #'s under light throttle seem ok @ 126-132 , but if I get in it , like 1/2-3/4 throttle it gets rich again , 110-117 . The injectors are stock size SVO 19lbs/hr , and a the car in question is a 350 TPI and I'm having NO drivabilty problems at all . Waddya think , is it because I'm outside the boundries of the stock chip or should I be looking elsewhere for my rich problem .

Here's a list of the mods that would effect the computer : Ram-air thru grill , air foil , ported plenum , Siamesed stock base , MSD-6AL / coil , edelbrock headers , 3" single out flowmaster , no cats or emissions , Buick GNX in tank pump , adjustable regulator ...heads/rockers/cam , runners and TB are all stock .

Thanx for any help

Rich Racing Team

------------------
Derek 90 IROC 5.7[/i]
Mods: All the usual bolt ons , siamesed stock base, 2500 stall , 373's , SS hood , lotta reduced weight.
Best Et: 13.12@101 ...1.701 60ft



[This message has been edited by 90 Z28SS (edited April 29, 2001).]

 

if you are using headers use a three wire o2 sensor if not you might have to burn a custom chip

 

also what year car is it any mod on a 90 or newer requires a custom ship speed density dosen't have the ability to compensate for mods

 

To my knowledge, and guys correct me if I am wrong, I thought that 350 TPI motors had 22lb injectors and the 305's came with 19. Could be a reason for the rich condition. Also as noted above with the O2 sensor, see if your car is in open or closed loop. If it's staying open then that is your rich problem and you have to figure out why it is open. Good luck.

 

his problem is because of the speed density..
its reading off. our systems dont compensate for this type of work.

talk to traxion. he has done all the work on SD engine managements. and he will help you!!

and you did come with 22lb injectors, and the three wire O2 isnt a bad idea.

i had this problem for a while, then figured out that my O2 was bad so i replaced it reprogrammed my comp, by unpluggin it, and then it all ran fine!!

talk to traxion he is an expert in this stuff!!

------------------
Jarrad
1990 IROC-Z L98 350 TPI
TH-700R4
G92- 7.5" 10 Bolt 3.23gears
Bright Red Hardtop/ Grey Custom Interior
5,507 IROC's Hardtops/Ttops; 2,415 5.7L IROC's Produced in 1990

DAILY DRIVER: 1991 S10 2.5L/5SPD WITH CAMARO RIMS

 

I do have a heated 3 wire 02 that is working how it should . What Im not getting is why is richer . With the given air flow mods I would fully understand having a lean problem @ WOT with the stock chip . I was thinkin , are there possibly default tables in the stock prom to compensate for a lean condition thats out of the computers correction factor ,that would run the car rich to be safe , kinda like a limp home mode . Does that at all make sense . If thats the case that would explain being rich under normal driving , but since there's no correction factor @ WOT I'd still be wonderin bout that.

Mass Air 350's had 22's and the SD 350's had 19's

Thanx for the comments guys

[This message has been edited by 90 Z28SS (edited April 30, 2001).]