Engine seems to run backwards.

[tmv36830]

Help, I took my 81 Turbo Trans Am to a friends shop so that he could address a few transmission leaks. I drove the car there with no problems. After my friend replaced the trans pan gasket he moved it outside and let it idle while attending to a few other customers. Well, the car cutoff and now when we try to start it the engine cranks, immediately dies and blows fuel out the carburetor and hisses like it is running backwards.

Has anyone had this happen and if so what were the steps you took to cure it. My first thoughts were that the ecm inside the distributor has gone bad or the brain box that resides under the center console.

Ideas?

 

[351maverick]

that's all ignition timing

 

[tmv36830]

that's all ignition timing

Are you thinking it jumped time or the electronics are causing the ignition timing issue. I am in agreement it is ignition related I just do not want to tear deep into this car due to its fragile wiring and hose routing from the factory. If anyone wants to know the worst years for 2nd gen cars just look at the 81's. Electonic carb, ecm's and a host of vacuum hoses that seem to eat the engine.

 

[hhott71]

Try a timing light first.
If it's way off, readjust it and take it for a test drive. If it stays put drive it some more.

 

[middleagecrisis]

Engines don't just jump time while idling. I guess it's possible that the distributor worked loose while it was idling. Did you hear any knocking/slapping noise coming from the timing cover area while it was running? Or did you not hear it running after the transmission filter change? Not trying to falsely blame anyone (aggressive test drive maybe?) but sounds like a slipped timing chain to me. Factory timing gears had nylon coating on the teeth and are prone to failure with age, especially if there abused. Bring the motor to TDC #1 and see if the balancer pointer is near 0 (TDC). You can also remove the accessory belts and check to see how much play you have in the timing chain. Put a socket on the crank bolt and attempt to turn the engine. If you have significant slop (inch or so movement in the rachet) before you feel resistance, then the chain has excessive wear. Hopefully, I'm wrong and just your ECM is fried. The TDC check is free and will keep you from replacing a perfectly good computer if the chain has slipped. Let us know.

 

[mickstan]

My buddy had a 77 V6 mustang that we popped started in reverse one day. He accidently put it in 1st instead of reverse when he popped the clutch. IT RAN BACKWARDS!!!! 4 speeds backwards and one forward! We laughed our asses off.

 

[tmv36830]

Engines don't just jump time while idling. I guess it's possible that the distributor worked loose while it was idling. Did you hear any knocking/slapping noise coming from the timing cover area while it was running? Or did you not hear it running after the transmission filter change? Not trying to falsely blame anyone (aggressive test drive maybe?) but sounds like a slipped timing chain to me. Factory timing gears had nylon coating on the teeth and are prone to failure with age, especially if there abused. Bring the motor to TDC #1 and see if the balancer pointer is near 0 (TDC). You can also remove the accessory belts and check to see how much play you have in the timing chain. Put a socket on the crank bolt and attempt to turn the engine. If you have significant slop (inch or so movement in the rachet) before you feel resistance, then the chain has excessive wear. Hopefully, I'm wrong and just your ECM is fried. The TDC check is free and will keep you from replacing a perfectly good computer if the chain has slipped. Let us know.

Thanks for that info. That will be my next step. I am so hoping I do not have to pull this engine apart. I was just trying to get the car ready to sell. But no, it has not got to leave my friends shop driveway. We race cars together and would never hide the fact if we dogged one another's car. We have always lived by the creed if it came apart on me it was going to come apart on him.

 

[markw]

Intake- Compression- Burn- Exhaust = normal running engine

Exhaust- Burn- Compression- Intake = how does this work?

I've had a few engines that dieseled so bad when you shut them off they sounded like they were running backwards but they weren't. A 'normal' reverse rotation engine (like in a boat with 2 engines) uses a different camshaft ground for reverse rotation. The only time I had one running backwards was on starting fluid (ether) and it wasn't running on gasoline because there was no gas in the carb.

 

[Cardinal]

I've seen this happen a couple of times. A perfectly good engine is shut off but when you go to restart it, it won't and backfires through the carb. Turns out the teeth on the cam gear on the timing gear set wore out = it needs a new timing chain gear set.

 

[Fbird]

Help, I took my 81 Turbo Trans Am to a friends shop so that he could address a few transmission leaks. I drove the car there with no problems. After my friend replaced the trans pan gasket he moved it outside and let it idle while attending to a few other customers. Well, the car cutoff and now when we try to start it the engine cranks, immediately dies and blows fuel out the carburetor and hisses like it is running backwards.

Has anyone had this happen and if so what were the steps you took to cure it. My first thoughts were that the ecm inside the distributor has gone bad or the brain box that resides under the center console.

Ideas?

actually just sounds like .....TRASH in the carb. (ie hung float)

Physically impossible to start backwards....(unless you change the starter and a few other things...)

or maybe the feedback carb is NOT feeding back.

You can "hot wire" this car pretty easy to BYPASS the ecm....