Sensors
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Joined: Sep 2004
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Sensors
How many sensors are there on a 89 MAF vette.
We have had 2 chips burned by 2 different tuners. No Luck at all
I keep hearing its a sensor,soo we run a data scan with a Snap On testor. testor relates back all sensors good. o2 moves fast etc
We tried New MAF sensor,no change.
New o2 sensor AC#AFS74
changed the tps,no change.
The only sensors left are air temp and coolant temp?
We have Black rich plugs & o2 sensor,engine runs for 45 seconds and sounds crisp then when the throttle is opened quickly the engine noses down.
Then I pulled the intake to keep the customer happy,installed a carb to show the engine build was good.
Engine responds great with carb.
Can't Data log this because the car is undriveable
Do any of the tuners on this board have any idea's???
We have had 2 chips burned by 2 different tuners. No Luck at all
I keep hearing its a sensor,soo we run a data scan with a Snap On testor. testor relates back all sensors good. o2 moves fast etc
We tried New MAF sensor,no change.
New o2 sensor AC#AFS74
changed the tps,no change.
The only sensors left are air temp and coolant temp?
We have Black rich plugs & o2 sensor,engine runs for 45 seconds and sounds crisp then when the throttle is opened quickly the engine noses down.
Then I pulled the intake to keep the customer happy,installed a carb to show the engine build was good.
Engine responds great with carb.
Can't Data log this because the car is undriveable
Do any of the tuners on this board have any idea's???
Last edited by 1uke; Nov 23, 2005 at 05:22 AM. Reason: delete
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Well, I guess my first thought is that if you don't know how Chevy FI works (and what's out there today, isn't a whole lot different from 15 years ago), find someone who does - especially, if you're doing this for Bucks or do we get to share in the profit?
I'd put the old chip in just to rule out the ECM and with your Snapon, check the Coolant Temp Signal with the engine cold - should be at ambient. I know some ECMs, including my own, suddenly develop a problem interpreting a correct signal and start toggling between 225 and 300. When that happens a cold motor isn't going to run.
Have you disconnected the MAF to see if it runs?
45 seconds should allow you to capture something - No, you're not going to get the O2 to respond, but sensor input is going to be there and might offer a clue.
I'd put the old chip in just to rule out the ECM and with your Snapon, check the Coolant Temp Signal with the engine cold - should be at ambient. I know some ECMs, including my own, suddenly develop a problem interpreting a correct signal and start toggling between 225 and 300. When that happens a cold motor isn't going to run.
Have you disconnected the MAF to see if it runs?
45 seconds should allow you to capture something - No, you're not going to get the O2 to respond, but sensor input is going to be there and might offer a clue.
Thread Starter
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Joined: Sep 2004
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you an start the car fine,it will run for maybe a minute total and develops pop when cranking the throttle open moderatley fast.
Scanners reads no airflow learned,tried a new MAF,Tps and changed to a heated O2.
Timings set,tps reads full sweep volts.
thanks
Scanners reads no airflow learned,tried a new MAF,Tps and changed to a heated O2.
Timings set,tps reads full sweep volts.
thanks
