So I just bought a '94 Z-28 with an automatic transmission. I am having an assortment of issues, and I'm trying to determine if they are all seperate problem components or if one component is causing a multitude of problems.

First, the car had a bad radiator. I've replaced that already and been venting the gas, but I've done that 4 times now, and still have to vent it. It tends to get hot after about 30 minutes of driving, and will boil out the resevoir tank.

Second, the car really hesitates if I try to pull away from a light under any kind of moderate to hard acceleration. It seems to bog down and not want to go, then all the sudden it will start to take-off. until...

The third problem. The car does not want to shift out of first gear. I can't tell if it is a tranny issue or the engine is still popping and not wanting to go and the computer isn't certain to shift. The engine will rev up to about 5k rpm. If I let off the pedal let it shift, then get on it again the car really takes off. This is about how I would expect the car to behave in all gears, but first gear really seems to cause problems. I've checked the tranny fluid and it is fine. I took it out of a drive and when under heavy acceleration the car started to bog down again. This time I stayed in the throttle to let a coworker hear/feel it and see if he had any ideas. The car sputtered for a few seconds then died. I had to let it cool before it would restart (~30-45 minutes). The guy I bought it from mentioned having rebuilt the tranny, so I'm not certain if perhaps he didn't do it right.

I've also noticed on 2 instances now (perhaps more, but I haven't noticed them due to lack of rear view mirror) under hard acceleration the car tends to blow out a cloud of thick black soot.

Here's what I'm thinking:
Overheating is caused by vapor in the coolant lines. I think if I keep burping it, that will get better. May also be that the fans aren't coming on soon enough. Thinking about wiring them directly to the ignition, so when the car is on the fans are on.

I'm thinking the sputtering and hesitating is from a bad opti-spark. I also noticed he had a box of new plug wires in the trunk, so those most likely need replaced and he just didn't feel like dealing with the hassle.

The lack of shifting from 1st I think is probably due to a spotty tranny rebuild. I am hoping a new opti-spark will make this go-away, maybe, please.

Any help you can provide would be appreciated.

Thanks,
-Matt-

 

the tran my be built to not shift until u let out and get back in it and it soude like everything else is spot on as for the soot the computer might need to tuned i recommend pcmforless they tuned mine

 

Is there a way to adjust the tranny to take that out. I've always thought the point of an automatic was to point it in the direction you want to go and put your foot down. It seems like that would be all the disadvantage of a manual with none of the advantages.

-Matt-

 

try adjusting the shift cable. it could be off by a little. are you seeing any coolant in the oil? to bleed the air out of the cooling system park the car on a steep hill with the front up. should have a place in the driveway that will work. i did mine when the front was up on jackstands. start with a cold motor. fill the radiator, open the bleeder screws till fluid comes out then close em, the bleeder screw on the heater hose will not bleed untill you start the motor so once you get the lower ones done start the motor and open the screw on the hose until you get fluid. refill the radiator and put cap on. take the car for a ride around the block and do it again.

 

No, I haven't seen any water in the oil. That was the first thing I checked when I went to look at it.

You mentioned the lower bleeders. I know where the two bleeders are on top by the intake. Where are the lower bleeders?

I'll have to check the shifter cable this weekend. I'm hoping to install the new opti-spark and a new AC compressor then as well. Gotta get that AC going here in FL.

Thanks,
-Matt-

 

sorry i was referring to the bleeders that are lower than the one on the hose. one on the thermostat cover and one on the bottom of the tb.

 

directions for adjusting trans cable
http://shbox.com/trans/A4_trans_linkage.html

 

Welcome to a great forum !!

Get it scanned to ck opti and other things.

Replace the thermostat ( 180 deg is ok ), waterpump, hoses, plug wires and plugs.

The heater hoses could also be leaking and if so, they will suck air when cooling off, ck for leaks and pressure in hoses when its warmed up, no pressuse is not good.

When you change the waterpump, remove the alternator, powersteering pump, disconnect exhaust from manifolds, remove fans and radiator. Then you can change those pita plug wires and spark plugs.

Try to find some heat resistant covers for the plug wires, especially on the passenger side and tie them up good.

Another problem with overheating could be the A/C condensor is clogged with sand, preventing good airflow through the radiator, so while everthing is out of the way, go ahead and pressure wash the A/C condensor from the bottom ( engine side )towards the front carefully, so not to dammage it with too much pressure !! You will be surprised how much sand and small rocks are in there.

Its a bit of work, but it cannot be boiling out the coolant, you will blow a head gasket.

I put blocks under the wheels to raise it high enough, see link below, be careful !

 

also is the air damn in place.

 

Good News and Bad News

I replaced the Opti, spark plugs, and wires, and it definitely seems to have made a difference. The shifting appears to be gone. My dad was driving it while I was dealing with a family emergency, and it he said it ran good. He said it seemed to hesitate slightly when pulling away from a light, but he also said anytime he pushed the pedal the rear tires broke loose, which means two things: 1.) I need a higher quality rear tire, the stock ones have plenty of tread, but apparently they aren't wet weather tires and 2.) It's got enough ***** to burn those cheap tires up. I'm a little curious about the hesitation, but I need to get behind the wheel and see what it's doing.

-Matt-