[89 ecm] Okay, what ELSE does it do?
Thread Starter
Burning Brakes
Joined: Feb 2000
Posts: 1,247
Likes: 2
From: Parker, Colorado, USofA
[89 ecm] Okay, what ELSE does it do?
I've got a Superram'd 383 with an Ed Wright chip in a stock ECU. Currently it's not receiving a Vehicle Speed Sensor signal, so I'm not getting torque Coverter lockup.
Now, when the battery's been disconnected for a bit, the car is REALLY hard to start, but it'll eventually figure things out and settle down. Fuel trims are right around 128, and the IAC is showing 30 counts or so when it goes closed loop.
Now here's the odd part: If you connect the A and F pins to force TC lockup, the car runs better. Smoother, idles better etc.
So what ELSE does shorting A and F together tell the ECU to do?
Now, when the battery's been disconnected for a bit, the car is REALLY hard to start, but it'll eventually figure things out and settle down. Fuel trims are right around 128, and the IAC is showing 30 counts or so when it goes closed loop.
Now here's the odd part: If you connect the A and F pins to force TC lockup, the car runs better. Smoother, idles better etc.
So what ELSE does shorting A and F together tell the ECU to do?
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Re: [89 ecm] Okay, what ELSE does it do? (RocketSled)
It sounds like you have a bad or open ground. I would check all the ground circuits, starting at the engine block, check the ECM grounds there, check ground straps to the body and chassis. If you have a wiring diagram for the ECM, check the continuity of all the ground circuits to the negative battery post. There should be no more than 3 to 5 ohm from the ECM to the battery post.
