I THINK ITS THE ECM!
Thread Starter
Registered User
Joined: Jun 2001
Posts: 65
From: HAMMOND
I THINK ITS THE ECM!
ok guys heres what happens while the car is open loop mode it will run fine but as soon as it goes into closed loop mode my air/fuel ratio gauge goes toward the lean area and then its like it shuts off.when i take off from from a stop it will chugg up till about 1500-2000 rpm.then the check engine light comes on,then when the car kicks into overdrive and the tc locks up, it feels like its locking and unlocking constantly.its getting real frustrating,it throws a code 33 which it says that the maf sensor is to high.know my tps sensor is set at +.65 and i was thinking that might be the reason but what do i know?and it also shows a code but i forgot what # but it says that its a egr problem.please help or shes gone ,my mods are in my sig and the cam thats in it is a little bigger than stock and the car use to be a 305 tpi.
------------------
1987 IROC-Z28
355 TPI
58MM HOLLEY TB
HOME PORTED PLENUM
LT1 INJECTORS
HEDMAN HEADERS
CRANE AFPR
MSD WIRES
JET FAN SWITCH.
3' 2 chamber flowmaster cat-back system.
STILL TO COME,
3:73 POSI DISK REAR
4' COWL HOOD
4TH GEN INTERIOR
ALL AROUND SUSPENSION KIT
------------------
1987 IROC-Z28
355 TPI
58MM HOLLEY TB
HOME PORTED PLENUM
LT1 INJECTORS
HEDMAN HEADERS
CRANE AFPR
MSD WIRES
JET FAN SWITCH.
3' 2 chamber flowmaster cat-back system.
STILL TO COME,
3:73 POSI DISK REAR
4' COWL HOOD
4TH GEN INTERIOR
ALL AROUND SUSPENSION KIT
Registered User
Joined: Nov 2000
Posts: 1,003
From: Grandville/ Grand Rapids, Michigan
You didn't have any programming work? You are running a modded 355 on a stock 305 chip? If so that is your problem. You can't just throw in 24#/hr injectors and expect them to work fine. You must tune your EPROM to run the car correctly.
Registered User
Joined: Nov 2000
Posts: 1,541
From: Sterling Heights, MI
<font face="Verdana, Arial" size="2">Originally posted by STAYBG:
ok guys heres what happens while the car is open loop mode it will run fine but as soon as it goes into closed loop mode my air/fuel ratio gauge goes toward the lean area and then its like it shuts off.when i take off from from a stop it will chugg up till about 1500-2000 rpm.then the check engine light comes on,then when the car kicks into overdrive and the tc locks up, it feels like its locking and unlocking constantly.its getting real frustrating,it throws a code 33 which it says that the maf sensor is to high.know my tps sensor is set at +.65 and i was thinking that might be the reason but what do i know?and it also shows a code but i forgot what # but it says that its a egr problem.please help or shes gone ,my mods are in my sig and the cam thats in it is a little bigger than stock and the car use to be a 305 tpi.
</font>
ok guys heres what happens while the car is open loop mode it will run fine but as soon as it goes into closed loop mode my air/fuel ratio gauge goes toward the lean area and then its like it shuts off.when i take off from from a stop it will chugg up till about 1500-2000 rpm.then the check engine light comes on,then when the car kicks into overdrive and the tc locks up, it feels like its locking and unlocking constantly.its getting real frustrating,it throws a code 33 which it says that the maf sensor is to high.know my tps sensor is set at +.65 and i was thinking that might be the reason but what do i know?and it also shows a code but i forgot what # but it says that its a egr problem.please help or shes gone ,my mods are in my sig and the cam thats in it is a little bigger than stock and the car use to be a 305 tpi.
</font>
Do you have an AFPR? If so, you will want to run the FP up around 50PSI.. Maybe a little more, but 50 is a good starting point.
The MAF is reading high because its looking for volume of that of a 305. You are sucking more air now and its fudging up the ECM. You definitely will resolve some issues by using a PROM from a 5.7 car of the same year.
You have a nice setup, but the programming really needs to be tuned to your specific combo as Brad indicated above.
------------------
Mike L.
1987 IROC Z 5.7 TPI A4 3.27 Borg-Warner four wheel disc
Mods: 2300-2500 Stall Converter, Shift Kit(GM parts), TPI Specialties Stage 3 PROM, Modified airbox w/ K&N's, Relocated MAT sensor, Gutted MAF, 160* thermostat, MSD 6A, Accel 8mm Wires, bypassed TB coolant, 3" Flowmaster 3 chamber single outlet, custom adjustable cutout, 3" MAC mandrel intermediate, airfoil, ported plenum. !smog, Crane AFPR, Accel rail mounted FP gauge, Harlan shiftlite, 24lb. injectors, Hedman headers, a few others I forgot...??? FINALLY GOT PAINT!!
Check out my IROC webpage!
[This message has been edited by IROC5.7TPI (edited July 14, 2002).]
Thread Starter
Registered User
Joined: Jun 2001
Posts: 65
From: HAMMOND
<font face="Verdana, Arial" size="2">Originally posted by IROC5.7TPI:
Ok, first set the TPS to the factory setting (.54)
Do you have an AFPR? If so, you will want to run the FP up around 50PSI.. Maybe a little more, but 50 is a good starting point.
The MAF is reading high because its looking for volume of that of a 305. You are sucking more air now and its fudging up the ECM. You definitely will resolve some issues by using a PROM from a 5.7 car of the same year.
You have a nice setup, but the programming really needs to be tuned to your specific combo as Brad indicated above.
Originally posted by STAYBG:
ok guys heres what happens while the car is open loop mode it will run fine but as soon as it goes into closed loop mode my air/fuel ratio gauge goes toward the lean area and then its like it shuts off.when i take off from from a stop it will chugg up till about 1500-2000 rpm.then the check engine light comes on,then when the car kicks into overdrive and the tc locks up, it feels like its locking and unlocking constantly.its getting real frustrating,it throws a code 33 which it says that the maf sensor is to high.know my tps sensor is set at +.65 and i was thinking that might be the reason but what do i know?and it also shows a code but i forgot what # but it says that its a egr problem.please help or shes gone ,my mods are in my sig and the cam thats in it is a little bigger than stock and the car use to be a 305 tpi.
</font>
ok guys heres what happens while the car is open loop mode it will run fine but as soon as it goes into closed loop mode my air/fuel ratio gauge goes toward the lean area and then its like it shuts off.when i take off from from a stop it will chugg up till about 1500-2000 rpm.then the check engine light comes on,then when the car kicks into overdrive and the tc locks up, it feels like its locking and unlocking constantly.its getting real frustrating,it throws a code 33 which it says that the maf sensor is to high.know my tps sensor is set at +.65 and i was thinking that might be the reason but what do i know?and it also shows a code but i forgot what # but it says that its a egr problem.please help or shes gone ,my mods are in my sig and the cam thats in it is a little bigger than stock and the car use to be a 305 tpi.
</font>
Do you have an AFPR? If so, you will want to run the FP up around 50PSI.. Maybe a little more, but 50 is a good starting point.
The MAF is reading high because its looking for volume of that of a 305. You are sucking more air now and its fudging up the ECM. You definitely will resolve some issues by using a PROM from a 5.7 car of the same year.
You have a nice setup, but the programming really needs to be tuned to your specific combo as Brad indicated above.
------------------
1987 IROC-Z28
355 TPI
58MM HOLLEY TB
HOME PORTED PLENUM
LT1 INJECTORS
HEDMAN HEADERS
CRANE AFPR
MSD WIRES
JET FAN SWITCH.
3' 2 chamber flowmaster cat-back system.
STILL TO COME,
3:73 POSI DISK REAR
4' COWL HOOD
4TH GEN INTERIOR
ALL AROUND SUSPENSION KIT
Registered User
Joined: Nov 2000
Posts: 1,003
From: Grandville/ Grand Rapids, Michigan
No... Hypertech and all the rest are just simply crappy. Thats NOT custom. You can burn your own chips... I am doing so at this current moment. Go to thirdgen.org and go to the DIY PROM board and read the article on top... the intro article.
Registered User
Joined: Nov 2000
Posts: 1,541
From: Sterling Heights, MI
<font face="Verdana, Arial" size="2">Originally posted by STAYBG:
OK SO WHO CAN I GET A CHIP BURNED WITHOUT PAYING ABOUT $500?</font>
OK SO WHO CAN I GET A CHIP BURNED WITHOUT PAYING ABOUT $500?</font>
C'mon Brad....hook 'em up
------------------
Mike L.
1987 IROC Z 5.7 TPI A4 3.27 Borg-Warner four wheel disc
Mods: 2300-2500 Stall Converter, Shift Kit(GM parts), TPI Specialties Stage 3 PROM, Modified airbox w/ K&N's, Relocated MAT sensor, Gutted MAF, 160* thermostat, MSD 6A, Accel 8mm Wires, bypassed TB coolant, 3" Flowmaster 3 chamber single outlet, custom adjustable cutout, 3" MAC mandrel intermediate, airfoil, ported plenum. !smog, Crane AFPR, Accel rail mounted FP gauge, Harlan shiftlite, 24lb. injectors, Hedman headers, a few others I forgot...??? FINALLY GOT PAINT!!
Check out my IROC webpage!
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