Hey, I recently purchased a '95 z28 vert auto wth 158k. When cold, the car seems to run fine. But once it's warmed up, it'll lose power for half a second then all of a a sudden get it back, and repeat. It almost feels like the trans is slipping at points. Sometimes i'll be cruising above 3k for a good 10 seconds before it shifts. The trans fluid level is good. I don't know if the clutch bands in the trans is going, or its just intermittently getting fuel blocked, possible clogged up injectors?

Maybe it's unrelated, but the fuel system doesn't seem to hold pressure. When it's cold it takes 3 or 4 cranks to start it. But if I crank it to the accessories for a few seconds to allow the fuel pump to run, and do that three times, then it starts up.

It'll hold revs fine in park though, doesn't seem that it doesnt have a fuel problem in that aspect. Could it be a pump, injectors or a trans problem? I've replaced the fuel filter and air filter so far.

I want to see if I can get any help before i pay for a shop to troubleshoot it.

Thanks

 

one issue is the fuel. test fuel pressure and test the fuel pressure regulator.
http://www.shbox.com/1/4th_gen_tech2...essure_testing
also change fuel filter. dump contents into a clear container so you can see if theres water or excess gunk.
http://shbox.com/1/fuel_filter.html
the trans sounds like it may be a valve body problem. if so its not that expensive to fix.

 

just curious what did you get the car for

 

2k from my gf's neighbor.

The problem has gotten alot worse, It'll just slip out of the gear and as you give it gas, the rpm's just kick up without the car going anywhere. It seems to catch back in gear down at a grand or so. I just dropped it off at a local garage, we'll see what they have to say.

Any other ideas will help. Thanks.

 

maybe the torque converter???

 

When i read your first post I thought "fuel pump is going." Second idea was oxygen sensors since the car ran fine when cold but not when warmed up (oxygen sensor data is ignored when the engine is cold).
Your update sure points toward a trans problem though. No engine problem will cause the trans to slip out of gear.
I look forward to hearing what the garage has to say.

 

Thanks for the help guys.

Garage said they were barely able to get the car back during the test drive, heh. Trans fluid was burnt and had metal shavings in it, they confirmed the trans was shot. Damn. Now I'm waiting to hear back from their trans shop they deal with to see if they're going and decide to rebuilt or whatnot and an estimate. They through out a number of 2k+, i'm hoping thats a new tranny, not a rebuild. We'll see though

Definitely considering a 4l60e t56 swap now, just because I'd imagine it'd be a little easier than rebuilding myself. I have a lift available to me. But I'll probably end up being a sucker and paying for my trans to be rebuilt.

 

Swapping out an auto for a manual in these cars is not a weekend job. There is a lot more involved than just adding a clutch pedal to the whole deal.

Question. Did you take it to a second shop to see what they think of the tranny? Pulling it out yourself and taking it in for bench rebuild should be a lot cheaper than $2k. Heck, you can get a reman with some upgraded internals for less than that.

Pulling and reinstalling the tranny is not that hard and can be done in your driveway.

 

http://www.700r4l60e.com/
http://www.transmissioncenter.net/4l60e.htm
http://www.performabuilt.com/About2008.html

 

When I had the engine and trans out of my 94 V6 (for an engine overhaul) I considered having a local shop "go through" the trans. Disassembly, inspection, new frictions and seals, reassembly. I figured it had 130k on it and the fluid looked like coffee (no cream) so it would be the smart thing to do. The shop wanted $750 for the job. That's with me pulling the trans and delivering it to their shop. Well the engine overhaul ballooned to almost $3k so trans work was out of the question. I reinstalled it as-is and it has been fine. Great, actually.

So $2k doesn't sound bad to me knowing that your trans *will* need hard parts in addition to frictions and seals. Plus they're doing R&I.

If you can do the R&I, have you considered a used trans? I just finished a transaxle swap in a neighbor's 2003 Dodge Grand Caravan. $500 for the used trans and $500 for me to do the swap. Owner was ecstatic since AAMCO quoted him $3000 for a rebuild and this was the 3rd time they were getting a crack at it. $500 for a used trans was a bargain and it is working flawlessly. It came with a 6 month, unlimited mileage guarantee. Do you have a good, professional salvage operation in your area?