After a long, Wisconsin winters nap, I officially worked on my 1981 TTA S/E.
The main issue I had with this car after purchasing it in November 2017, was cold starting. It would not stay running. Once warmed up, it stayed running and idled OK, but you could tell it was running very rich.
Being that this is a 1981 US Spec car, it is equipped with Computer Command Control (CCC). This means it has an engine computer (ECM) that controls the metering rods in the carburetor. It also has other electrical sensors like a Throttle Position Sensor (TPS) and Oxygen Sensor (O2). There was no check engine light on when I got the car, so that was a good sign.
I knew the issue with cold starts had to be carburetor related. During the winter months, I rebuilt an extra 1981 carburetor to swap out at a later date.
That day came on May 28th 2018. With rebuilt carb ready to go, I swapped it out along with a set of new NGK UR5 (2771) spark plugs gapped at .035". The old spark plugs were very black with soot. The oil and filter was also changed at that time.
After a brief problem with the Mixture Control Solenoid (MCS) connector causing a check engine light, the car ran great. No more stalling cold and the idle was beautiful.
A quick ride to put some fresh gas in it brought about the next problem. It looks like the right front brake caliper is not releasing causing a nasty pull to the right and the smell of burning brake pads.
Back into the garage where it will sit until I can get time again to fix the brakes. This might bring about a new product for TTA Performance in the form of a braided stainless brake hose kit.
Replaced both front brake calipers on the TA. I decided to try out some braided brake hoses for the car too. I think I will be offering these hoses for sale soon. They worked out well and fit great.
I did have trouble removing the steel brake line from the hose on the driver's side. So, I re-made the steel line.
I then noticed a bulge in the tread of the right front tire. It was starting to split between the blocks of tread. I already ordered new Cooper Cobra GT tires (255-60-15) but they are not here yet. After bleeding the brakes, I took the car for a quick ride around the block and parked it back into the garage.
Went to install the new Cooper Cobra tires. Got quite the shock when I went to remove the right front. This is what happened just from sitting in the garage for 2 weeks. Glad I didn’t drive the car.
Be sure to always check your tires. Just because they have deep tread, doesn’t mean they are good. Age is also a factor.
New Cooper Cobra Radial GT tires. 255-60-15
Drove the car a couple times. Short trips in town. My cousins shop, the parts store. It was running great. Tires rub the front fenders when you hit a dip in the road. I’m not too concerned because I like the look of the large 255s.
Took the family around the corner to Culver's for dinner, got food to go, came out......no start.
No movement from the tach when cranking. Lost spark.
ESC? Wait! 1981 CCC. If the ESC is bad, I can unplug the ESC connector at the distributor and it should start. Nope. Ugh. Must be an ignition module?
Walk home to eat dinner leaving the car in the parking lot.
Go back with tools and a used ignition module and swap it in the parking lot. Still no spark. Coil?
Run home and grab a coil. Nope, still no spark.
Tow the car home with the wife's Jeep and a tow strap and wait until tomorrow.
Started doing some testing. I have key on power to the coil. That’s good. I decide to remove the distributor to test and rebuild if necessary.
Distributor out, I removed the ignition module. A few of the plastic connectors to the module were broken, so I replaced it with another distributor harness I had.
I wanted to check the magnetic pick up coil. According to the factory service manual, the magnetic pick up should have a resistance value of 500-1500 Ohms. Mine measured 790 Ohms. A spare distributor measured the same.
Another test I like to do is hook up my volt meter to the 2 magnetic pick up wires and measure AC voltage while spinning the distributor. My distributor did show a small voltage signal, but not like my spare distributor.
Not wanting to take any chances on used parts, I decided to rebuild the distributor with a new magnetic pick up, new ignition module, new distributor cap and rotor. Everything was installed and the car started right up. I set the timing with the ESC connector unplugged at the distributor and everything looked right, but the exhaust didn’t sound right. It had a very deep rumble in the mufflers. It didn’t sound the same as before. The engine didn’t seem to want to rev up very easy either. A quick ride around the block confirmed that something was wrong. It was just a slow pig. Could not get out of it’s own way. Sounded and felt like the timing is retarded.
Took out my timing light. My suspicions were correct. The timing was showing badly retarded with the ESC plugged in. Disconnect the ESC connector at the distributor and the timing was showing 6 degrees advanced like I set it to. It looked like the ESC was retarding the timing for no reason. The knock sensor was not even plugged in.
First thing I did was by pass the ESC box at the ESC connector with one of my boards. Timing was no longer retarded with the distributor plugged in. Watching the timing and increasing RPM showed the timing advancing like it should. The exhaust sounded much better and the engine felt more alive. Too late to drive it, but it looks like it is all fixed.
Seems like every time I drive this car it is an episode of Roadkill.
My son and I wanted to go for a cruise with the t-tops off last night. It was a nice day.
Cruising down the road at 35 MPH, I notice that the car shuts off and tach goes to 0. Uh oh. Before I could react, all of a sudden, the engine comes back on with a loud "bang" out of the exhaust.
I just turned around and drove back home with no issues after that.
For some reason I lost spark while driving down the road. Since I was at speed, the engine was still rotating and putting fuel down the engine and out the exhaust. When the spark came back, it lit the fuel in the exhaust and that was the loud backfire.
I am suspecting the cheap ignition module from O'Reillys. It may have a problem with heat or is just an inferior product. I wanted a name brand one, but at the time, they did not have one in stock.
I decided to order a Standard brand ignition module to swap into it.
Found some time to install the Standard ignition module.
Installed it in the distributor (kept the tach wire unplugged) and things just got weird from there.
Right away, I notice it sounds like it is cutting out as it is running. Just very quick hiccups in the exhaust. I then accelerate the engine to see the check engine light coming on. It would come on and go off from engine acceleration. I have never had that happen.
I took out my Snap-On scanner to check for codes. But without the check engine light on steady, I had no codes to read. Accelerating the engine with the scanner plugged in won't do anything because with the scanner in diagnostic mode, the engine runs differently.
It was getting late, so I unplugged the scanner and started to reassemble the air cleaner (engine running). I throttled it up one more time from under the hood when the idle dropped really low and the check engine light came on steady.
Grabbed the scanner again and checked codes. Code 12-RPM reference. That to me was odd since that is the code you get in diagnostic mode with the engine off. I packed it up for the evening and decided to look at it a different day.
Looking in the service manual, code 12 has a small trouble shooting chart. It asks to measure voltage at pin 10 of the ECM and see if the voltage increases with RPM. If it does not, it is a bad connection or a bad ignition module. Great, now this new ignition module could be bad?
Frustrated with the situation, I was ready to throw in the towel with the 37 year old technology and ECM. I placed an order for a CB Performance "black box" programmable ignition box that I can modify to take the place of the factory ignition module. This will allow me to make my own timing curve using a laptop to program. Very similar to an MSD 6AL-2, but half the cost and more options. I was going to internally convert the carb to a mechanical fuel enrichment system and eliminate the ECM too.
The next day, I had time to go out and work on the car one last time.
I decided to replace the ignition module again, but with a used GM unit I had that looked to be in good shape.
I am really getting good and replacing the ignition module in a 301T.
I had the GM module installed in no time. Hit the key and the car started up and ran great. No hiccups. No check engine light. I still left the tach wire off. I didn't have time to take the car for a ride as rain was coming. So, I had to call it a night.
The next day, we had enough of a break in the rain to take the car for a quick ride. It drove great. No check engine light. No backfire. No glitches. It actually runs very well and makes a good amount of power. Still don't know how much boost I am making.
Next step is to drive it more, then plug the tach back in and drive it again. Just to make sure it doesn't back fire any more.
A sad day today. We lost the man that made the black and gold SE Trans Am such an unforgettable icon. Mr. Burt Reynolds, The Bandit, passed away at 82 years old.
In honor of his passing, I took the car for a ride with my son.
This time, I plugged in the tach. No issues on the drive. Car ran great. Noticed that the tach is reading 1000 RPM higher than actual.
Fixed a few things on the car over the weekend. Mainly cosmetic.
Replaced the driver's side outer window seal. Replaced the broken outside door handle. Installed a used door panel that was in better shape than my original. Still need to do this on the passenger side.
Mounted a temporary boost gauge in the car and took it for a ride. Making a solid 5 psi. Car runs great and pulls great. No plans to increase the boost just yet.
Drove it to work for the first time. It made the 30 minute drive just fine. Has an oil leak that must be getting on the exhaust because you can smell it while driving. Could be valve cover gaskets, but I have a feeling it is the rear main crankshaft seal leaking.
A friend of mine likes to get us "car guys" together on Friday nights to go cruise our cars around. This time we were going to a diner not to far out of town. My son and I decided to take the TTA.
She cruised out there with no problems. The minute we pulled up in the parking lot, someone in a Chevy pick up stopped along side me and asked what the chances were that I would sell my car. I told him the chances were very slim.
After dinner, my cousins and I decided to take the kids to do some go-karting. I knew my dashboard lights didn't work but my headlights did. I had checked the fuse earlier and it was good. I flipped on the headlights and turned the dimmer knob a few times and the dash lights came on!
Had a blast go-karting and then drove home with no problems.
I wanted to drive the car one more time to work before putting it up for the winter.
Unfortunately, it refused my request.
The mechanical fuel pump decided to leak really bad when running. So, it was replaced today and put into indoor storage until next spring.
Plans for next year:
It has been in storage too long. Usually I would have my cars out way before July, but we seemed to have a very late and wet spring and with customer's cars taking priority and all my time, I didn't have time for my car.
It is out of storage and was driven straight over to the shop. Going to be installing some freshly restored front control arms with all new Moog bushings and ball joints. I will also be installing some low mileage, used WS6 front springs. Yes, this car was originally not a WS6. After the suspension install, I might take it to the local drag strip to bench mark it's performance before making modifications. It will be slow with 5 psi of boost and everything stock, but you have to start somewhere.