2 cents here please!
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Instructor
Joined: Nov 2008
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From: Odessa Tx
2 cents here please!
On my 85 I have replaced the following....O2 sensor, IAT sensor, MAF sensor, BURN OFF MODULE, plugs, wires, coil, cap, rotor...set the timing correct, set the TPS correctly to.54v, cleaned the TB....much more.
I had a code 33 and when I put the new burn off module and MAf on the light went off but the car ran like crap. It would start off good if you went slow and then it will lose power during acceleration and throw you forward as if the brakes were on( The brakes arent literally on it just feels that way). The motor seems to rev but not loudly and the motor has no power after about 20MPH. I unplugged the MAF and got code 33 back but the car runs better without the MAF still. I am stumped! Any help is appreciated. I guess I could just stare at the engine light lol.
I had a code 33 and when I put the new burn off module and MAf on the light went off but the car ran like crap. It would start off good if you went slow and then it will lose power during acceleration and throw you forward as if the brakes were on( The brakes arent literally on it just feels that way). The motor seems to rev but not loudly and the motor has no power after about 20MPH. I unplugged the MAF and got code 33 back but the car runs better without the MAF still. I am stumped! Any help is appreciated. I guess I could just stare at the engine light lol.
Max G’s
Joined: Nov 2008
Posts: 2,751
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From: Monroe OH
NCM Sinkhole Donor
Try to disconnect the power for 10 minutes. Then see what happens, also, did you set your timing from the emmissions decal under hood? I had a bad burn off relay in a 88 GTA and kept getting a code, but it still ran good. Also, maybe try to push throttle to wide open and see what happens. Good Luck.
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Instructor
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From: Odessa Tx
I am almost to the point that I am satisfied without the MAF hooked up but when I am driving it around and the motor gets warm, at traffic lights the motor idles real low and almost dies. I have to take it out of drive and put it in neutral to keep the motor going at a light.
Corvette Enthusiast
Joined: Oct 2007
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From: So. Cal.
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Maf
Just because you have a new MAF doesnt nessessarly mean its good. I have recieved bad ones before when exchanging with an auto parts stores. If its a rebuilt unit it may not be good. Just my MAF experiences.
Good luck.
Good luck.
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Drifting
Joined: Feb 2003
Posts: 1,976
Likes: 2
From: San Antonio Texas
Check your Coolent Temperature Sensor and its' connection. It will sometimes give problems like this; at least on '86+ years. '85s have a slightly different setup than other years; I know they use different Relays for instance. A FSM would help a lot... With it you don't have to just throw parts at the thing.
Melting Slicks
Joined: Jan 2008
Posts: 2,065
Likes: 1
From: Jasper Texas
Lets go back to the basics. You need to check your fuel system:
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
Also, try running the car with the est wire disconnected and see what happens. Mine ran very smooth when it was disconnected due to a timing problem. Is it possible that your balancer has slipped and you set the timing wrong?
You can ohm check the coolant temp sensor:
temp-----ohms
210------185
160------450
100------1800
70-------3400
40-------7500
20-------13500
0--------25000
-40------100700
The symptoms almost remind me of a bad esc (electronic spark control) module. A $50 part from autozone, but I wouldn't throw any more parts at it until you do some more testing.
Its a good Maf. I sold it to him, it worked fine.
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
Also, try running the car with the est wire disconnected and see what happens. Mine ran very smooth when it was disconnected due to a timing problem. Is it possible that your balancer has slipped and you set the timing wrong?
You can ohm check the coolant temp sensor:
temp-----ohms
210------185
160------450
100------1800
70-------3400
40-------7500
20-------13500
0--------25000
-40------100700
The symptoms almost remind me of a bad esc (electronic spark control) module. A $50 part from autozone, but I wouldn't throw any more parts at it until you do some more testing.
Its a good Maf. I sold it to him, it worked fine.
Burning Brakes
Joined: Nov 2007
Posts: 1,213
Likes: 2
From: Cincinnati oh
I had a simmular probelm and when you check your Fuel pressure check your fule Volume, if you hit the button and the motor dies you need a new fuel pressure regulator.
Took me a month of sundays and 2 fuel pumps to figure it out (well my mechanic Jerry)
Took me a month of sundays and 2 fuel pumps to figure it out (well my mechanic Jerry)
Le Mans Master
Joined: Jul 2007
Posts: 5,043
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From: Tampa Florida
Thread Starter
Instructor
Joined: Nov 2008
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From: Odessa Tx
There is a vacumm hose hooked up to it however I wasnt sure what it was and I think I screwed out , or did I screw in?...I dont know I did something to it a while back and I might need to set it now I guess....
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
If the Fuel Regulator has a screw on top of it...it is an adjustable Fuel Pressure Regulator. If you altered the screw in the recent past you may have found your issue. You'll need to hook up a fuel pressure gage and run the fuel pump to readjust the setting back to where it should be....and go from there
Last edited by engle1147; Jan 27, 2009 at 08:38 PM.
Melting Slicks
Joined: Jan 2008
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From: Jasper Texas
Thread Starter
Instructor
Joined: Nov 2008
Posts: 170
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From: Odessa Tx
Ok I got a fuel pressure tester and here is what I have got:
when I just turn on the key without turning the enine over or on it goes up to 54psi and goes back down to 20 psi
when I start the car at idle I have 50psi and its pretty much around 50 psi as I rev the motor and may even loose a bit down to 48 at high rpms.....
So is this good or not? I have never messed with fuel injection before.
when I just turn on the key without turning the enine over or on it goes up to 54psi and goes back down to 20 psi
when I start the car at idle I have 50psi and its pretty much around 50 psi as I rev the motor and may even loose a bit down to 48 at high rpms.....
So is this good or not? I have never messed with fuel injection before.