After working on the tranny cooler lines, an upshift problem suddenly appeared. Originally posted in the Garage "Mechanical and Troubleshooting" section, this thread details how the problem was resolved, courtesy of David/Turbokinetic:
Problem: old ATF in the tranny.
When I was refurbishing the tranny oil cooler lines, the ATF looked a bit stale to me. It was probably the original fluid and had been circulating in the tranny for the past 23 years. I figured it was time for a change.
With 76,105 miles on the odometer, the old fluid on the dipstick looked a tad oxidized as evidenced by its slightly brownish color. Prior to dropping the pan, I bought a new ACDelco pan gasket, filter & seal kit (ACDelco #8652910).
Casting number on my Cieraís 3-speed TH125C/3T40 tranny.
Apparently manufactured in the Windsor plant as indicated on the bar code sticker.
Here Iím loosening up the pan bolts and transmission fluid is starting to seep out. I marked the one long bolt with Wite-Out to distinguish it from the other bolts. The field service manual explicitly states that the long bolt has to go back into the same hole it came out of.
To make sure I didnít lose any pan bolts, I noted the count and inserted them into a piece of a cardboard, taking care to note the location of the marked long bolt with respect to the pan and the other bolts.
Old fluid and filter. This job can be messy so I used this plastic tub to catch the fluid and plenty of newspapers underneath to minimize splatter. Once the pan was off, I pulled the filter.
Bottom of tranny with pan off.
Inside of tranny pan with magnet.
Close-up of magnet.
Typical sludge from the magnet on my finger.
I gently used a razor blade to remove residual gasket material, taking care not to gouge the sealing surface.
Comparison of old and new filters.
I couldnít get the old seal out, so I left it in place.
New filter in place.
New ACDelco pan gasket.
Pan gasket, filter & seal kit part numbers on label.
New gasket tacked to the now-clean pan with a few strategically placed dabs of sticky adhesive in order to prevent gasket movement before reinstallation of pan bolts.
Pan back on and bolts torqued to spec with a 3/8Ē drive torque wrench. The long bolt marked with Wite-Out is back in its proper place. Next time I have the pan off, maybe I'll paint it.
New ATF for the tranny. I did some research to ensure compatibiltity with the old original Dex II fluid specification.
Paper towel test: old brownish fluid on paper towel on the left; fresher, pinkish fluid on the right. Checked for leaks several times; the pan was dry - no leaks = job done! Shift quality improved, too - smoother!
Last edited by 93CieraDude; 04-22-2017 at 07:03 PM.
Nice job on the lines! I'm up under there on my project right now. In my case I have a new set, but your pics are so nice. It has allowed me to compare the routing of lines going back together. Did you lose much trans fluid when you pulled the lines. I lost more than a pint.
You mentioned that you used 400 PSI trans fluid hose. What kind of pressures are we talking about on the trans cooler lines. Not that that much, right?
Problem: intermittent stalling increasing in frequency/fuel pump diagnosis
Driving home from his job one evening, my son reported that the Ciera stalled out on him. The engine started right back up and he drove the rest of the way home without further incident. I looked into it but my cursory checks didnít uncover anything obvious. Soon after, I had the same thing happen to me while driving the car myself. That really got my attention. Over the next couple of weeks, a pattern developed. The stalls seemed to be at random, occurred only occasionally, and were unpredictable. Then the stalling incidents began increasing in frequency, to the point of making the Ciera unreliable and unsafe to drive.
While previously diagnosing a misfire earlier in my makeover thread (which turned out to be corrosion of the #1 spark plug and wire boot connector), I did cold resistance checks on the fuel injectors. The injectors had ohmed out to spec and the engine seemed to run fine once I replaced the #1 spark plug wire.
In addition to other suspects, I was now concerned that one or more of the OEM Multec fuel injectors in this so-called batch-fire ignition system might be intermittently shorting out when hot, thus killing the injector driver circuit and shutting the engine down. Before implicating the injectors however, I wanted to check the fuel pressure.
I hooked up a fuel pressure gauge to the fuel system.
The hook-up was a pain to do because a black metal support bracket in front of the rear valve cover was in the way just enough to impede access to the Schrader valve located on the rear of the fuel rail. I didnít have an angled adapter, so once I moved the bracket out of the way, I was good to go.
Close-up of the fuel pressure gauge-to-Schrader valve connection.
When I turned the ignition key to the on position, I could hear the fuel pump prime as usual, so I knew the fuel pump relay was functional. With the ignition key on and the engine off, the fuel pressure gauge registered a primed pressure of 40 PSI, as seen here through the windshield from the driverís seat.
I then started the engine and let it run. As the engine warmed up to operating temperature, lo and behold, the fuel pressure reading began to drop.
And dropped some more Ö
All the way down to 14 PSI. The engine sputtered and stalled. Needless to say, I found the culprit: a dying fuel pump.
As for the rest of the fuel system, the fuel filter looked to be original. Iíll bet the previous owner never had it changed. The car seemed to accelerate fine at wide-open throttle, so I didn't think the filter was clogged to the point of stressing the fuel pump. But it sure wouldn't hurt to install a new filter.
Being a rust-belt car, the fuel tank had its share of corrosion. The rust on the upper half of the tank was flaking and left me wondering about the possibility of pinholes perforating the metal in areas I couldnít see. Too tight to get a mirror and light up in there to view the top of the tank.
I had concerns about the fuel filler neck, too. Here you can see the rusted neck coming down towards the fuel tank.
And its junction with the fuel tank hoses. Some flaking there, too. Rust never sleeps ...
After mulling all this over for a bit, I opted for a fresh start. I want to be sure the Ciera is reliable for my son to drive when he needs it. He doesn't know much about cars (yet), and I don't want to have to worry about him getting stranded somewhere. So I decided to replace the fuel tank and straps, fuel pump assembly, fuel filler neck and fuel filter. Time for some serious wrenching, now. Up next: back-end fuel system rebuild.
Last edited by 93CieraDude; 04-21-2017 at 01:09 AM.
You might want to take a look at this: https://www.a-body.net/forums/showth...t-s-in-the-box
I did a close look at fuel filters for the a-body. I haven't cut them open yet, but I can tell you that the OEM filters on my '95 and '96 cars were plastic. Skip made a comment that GM OEM changed suppliers occasionally (he was a GM parts guy), but his '93 had the same plastic filter as mine did.