naamatis

I'm not sure if this is what I am attempting to describe or not, but I will try to describe the sysmptom and see if anyone can tell me if I am understanding this correctly.

I have a 1985 Chevy G20 3/4 Ton van that has about 108k miles on it. It has an automatic transmission and I just recently did some engine work on it to improve the performance. It seemed to work, but I am having some troubles with hills.

On semi-level roads, the acceleration seems to be slow. The engine sounds like it is working a bit harder than it should when gearin up. I figured this was normal, but it might not be because, when I am driving on an incline, any incline, the acceleration just seems to drop off and it won't gear up no matter how much gas I give it. Pressing the pedal to the floor doesn't even seem to do the trick.

So, I am wondering if there is something I can look at to try to resolve this issue or if anyone has any ideas as to what might be causing this because I am at a loss at this point.

maxxman04

check the timing. does it make a pinging sound, or blow black smoke out exhaust? what kind of work did you do?

naamatis

Well, I did tune the timing a bit before because it was idling too low. I also added a primary choke to the carb because there wasn't one and replaced the vaccum advance. Replaced all the spark plugs and did an oil change with some basic oil, wasn't anything special.

I did notice a little bit of black smoke coming out the exhaust today after shutting down the engine, but it hasn't done that while driving that I have noticed. It sounds like the engine is reving up as high as it will go, but not kicking into the next gear while going uphill. It does not make any pinging sounds or anything like that.

Could it be something with the fuel pump? I was thinking possibly an issue with the transmission, but I'm pretty sure the transmission was recently rebuilt...or at least it appears that it has been. I'm not sure though.

gotstylez

kickdown cable?

naamatis

This may make me sound like an idiot, but WTF is that? lol

maxxman04

grab a timing light, check the timing. i'll bet it's off. the black smoke indicates there's too much fuel, or your timing is "retarded". those are the most common reasons. timing should never be used to compensate for idle. there is a screw on the side of the carb for that. go thru entire ignition system again. all the spark plugs, cap, rotor, wires. make sure all are good, and make sure plug wires go to the right place. make sure there are no vacuum leaks.

kickdown cable is the cable that runs from the carb down to tranny. it "kicks" the tranny into passing gear while driving when you step on the gas hard. basically.

naamatis

The timing appears to be fine...and the acceleration was sluggish for half the day today and then suddenly stopped being sluggish. The spark plugs, wires, cap, rotor are all good and go to the right place. The fuel pump looks ancient and I will be replacing that. A guy at the parts store suggested that the accelerator pump diaphram might have a leak in it. Could that be causing the acceleration to be sluggish?

I also just bought an engine thermostat and gasket to replace what is there and I've been told that I need a new choke thermostat as well. May end up having to completely rebuild the carb, but I am hoping it doesn't come to that because it's a 4 barrel carb and will be a pain to rebuild.

Anyway, if anyone else has any more ideas, please share. I'd be gald to take any other ideas into consideration.

Thanks