Need help with a sudden problem...
Need help with a sudden problem... Background info:
1998 Camaro SS LS1 engine and T56 tranny
swapped into a 1990 Mazda RX-7
engine is running 2002 cast exhaust manifolds
pcm tuned by wait4me performance
removed AIR, rear o2s, EGR
all other sensors are installed and functioning
the car had been driving great. has about 200-300 miles on it since install. nothing out of the ordinary
now just last night while cruising in town at around 35 mph it all changed. i had not been driving it hard or anything when the symptoms appeared.
lost power, runs rough under heavy acceleration. stumbling under heavy acceleration. while cruising gently it feels almost totally normal. only thing is there is a barely detectable surging while cruising at steady speed. idle is almost totally normal. under deceleration it seems to backfire more than it used to
I know I need to try to pull codes to figure out what was going on. problem is I do not have the obd2 port wired yet. i was just hoping someone could give me a shot in the dark idea as to what might have gone wrong. i hope to get my obd2 port wired either tomorrow night or thursday and then scan it.
any ideas? i would really love some insight from you guys. my wild guesses are either o2 sensors or maybe a coil. someone told me it could also be the knock sensors.
-Curt
1998 Camaro SS LS1 engine and T56 tranny
swapped into a 1990 Mazda RX-7
engine is running 2002 cast exhaust manifolds
pcm tuned by wait4me performance
removed AIR, rear o2s, EGR
all other sensors are installed and functioning
the car had been driving great. has about 200-300 miles on it since install. nothing out of the ordinary
now just last night while cruising in town at around 35 mph it all changed. i had not been driving it hard or anything when the symptoms appeared.
lost power, runs rough under heavy acceleration. stumbling under heavy acceleration. while cruising gently it feels almost totally normal. only thing is there is a barely detectable surging while cruising at steady speed. idle is almost totally normal. under deceleration it seems to backfire more than it used to
I know I need to try to pull codes to figure out what was going on. problem is I do not have the obd2 port wired yet. i was just hoping someone could give me a shot in the dark idea as to what might have gone wrong. i hope to get my obd2 port wired either tomorrow night or thursday and then scan it.
any ideas? i would really love some insight from you guys. my wild guesses are either o2 sensors or maybe a coil. someone told me it could also be the knock sensors.
-Curt
yeah i thought it felt just the tiniest bit rough before the problem arose. but it didnt seem like a big enough deal to worry me. now it def. needs some help. i will get the obd2 port hooked up and the codes scanned asap
FormerVendor
Joined: Aug 2005
Posts: 531
Likes: 0
From: Decatur IN.
well really it could be almost anything i would fire the tuner first,check for vacum leaks,pull the plugs(w/2-300 miles Iwould do this if there where no problems)and get that ALDL hooked and scan that donkey...
still havent had a chance to get the scan port wired up. i actually lost the stupid thing. i did do a couple little tests though
tested coils with a timing light. all coils are firing.
unplugged MAF and started the engine. the engine will barely even run with the MAF unplugged. it will idle somewhat normally but as soon as you open the throttle a bit it bogs heavily and will not clear up unless the throttle is opened all the way and even then it takes it a couple seconds to clear.
MAP sensor??
tested coils with a timing light. all coils are firing.
unplugged MAF and started the engine. the engine will barely even run with the MAF unplugged. it will idle somewhat normally but as soon as you open the throttle a bit it bogs heavily and will not clear up unless the throttle is opened all the way and even then it takes it a couple seconds to clear.
MAP sensor??
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yeah i know... 
i just wish i could figure something out that would make it clear cut what is wrong with it. i wont drive it until its right and i can't find my damn scan port to wire it in. maybe i will just go take one from a car in a junk yard.
i just wish i could figure something out that would make it clear cut what is wrong with it. i wont drive it until its right and i can't find my damn scan port to wire it in. maybe i will just go take one from a car in a junk yard. LS1 Tech Stories
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Have you checked fuel pressure? 58 psi?It was running good then all of the suddon quit?
Have you checked for power at the o2 sensors? No blown fuses?
IF you come to me on sunday, i will help you wire it up and find out what your problem is, im in warsaw indiana and will get you taken care of. And... Ill give you a ride in a 1000 horsepower camaro.
i am running a corvette fpr/fuel filter.
no fuses have blown. i wired up 4 pink wires and 1 orange.
i would try to come there on sunday but i am currently in bloomington IL and that is one hell of a drive for a car that is not running right
no fuses have blown. i wired up 4 pink wires and 1 orange.
i would try to come there on sunday but i am currently in bloomington IL and that is one hell of a drive for a car that is not running right
ok so after turning the garage upside down i finally located my obd2 port and wired it up today. i disconnected the battery while doing the wiring (maybe half an hour) then connected it back up and drove it about 8 miles to the local auto zone. here are the results
5 codes pulled.
map sensor low voltage
bank 1 o2 seonsor low voltage
bank 1 o2 sensor not responding
bank 2 o2 sensor low voltage
bank 2 o2 sensor not responding
that is what the guy said. (probably not exact words) i was not able to get a look at the scan tool myself to confirm.
some more background on the engine. the engine has between 40 and 45k on it as far as mileage goes. it used to have hooker long tube headers on it. the o2s look to be original. the o2s are now located maybe a foot down stream of the 2002 cast manifolds.
i am planning to replace the o2s with the rear corvette sensors and get a new map sensor.
thoughts? comments? opinions?
5 codes pulled.
map sensor low voltage
bank 1 o2 seonsor low voltage
bank 1 o2 sensor not responding
bank 2 o2 sensor low voltage
bank 2 o2 sensor not responding
that is what the guy said. (probably not exact words) i was not able to get a look at the scan tool myself to confirm.
some more background on the engine. the engine has between 40 and 45k on it as far as mileage goes. it used to have hooker long tube headers on it. the o2s look to be original. the o2s are now located maybe a foot down stream of the 2002 cast manifolds.
i am planning to replace the o2s with the rear corvette sensors and get a new map sensor.
thoughts? comments? opinions?
i now have the new map sensor and o2 sensors to fix the car... i am nearly 100% sure that the current sensors are getting power, but should i check them to be sure? what wires should be hot with the car running?