Hey I'm pretty new to the forums, joined about a month or two ago to start reading posts when I bought my 87 Iroc-Z with a 305 engine. This is the first car I've bought on my own, and I have had no previous experience with cars, so please have patience with me lol.

Anyways, I bought my car knowing that something was wrong with the carburetor because when the engine was completely cold, it was having a hell of a time starting up. It took at least 5 minutes of giving the car gas to finally get it going. From what I understand, I think this was the car's original carb, but I could be wrong. I'm not sure how to check.

So I took the car to a mechanic nearby who has worked on my dads cars before at a reasonable price, and asked him to take a look. A week and $170 later, I'm informed that the carb had been rebuilt, but now the car just refuses to accelerate. The engine roars, but the car just won't accelerate. He told me he was not able to do the rebuild himself and had to take it to another mechanic. That other mechanic now says nothing is wrong with the carb, and he doesn't know what is wrong with the car.

The car no longer has trouble starting up, I just have to give it a little gas while starting (I'm assuming that's normal. Regardless, it's better than the previous situation). No check engine light comes up when I start the car either. The mechanic also replaced the fuel pump.

Any help is GREATLY appreciated, I just want to get a few opinions before I take this to yet another mechanic. I have no idea whether I need a new carb or something completely different. I'm dying to get behind the wheel! Thanks in advance

 

1) Your car has an in-tank fuel pump that is a 'helper pump' to the mechanical pump on the block ... do you hear this pump running with key on?

2) Your carb is a computer controlled carb, and thus has various sensors on it, are they all plugged in correctly?

3) There is a way to test some of them. IAC can be cleaned, think TPS can be tested for resistance ranges with an ohm meter. Maybe search IAC and TPS and research some on this here

4) What's timing set at? Maybe a previous owner changed timing trying to compensate for the bad carb issue or something - unplug the EST wire, start car and check base timing is within specs.

 

Making noise, like it revs up but the car doesn't respond? OR making noise like it's trying to suck more air in but it's not blindingly fast?

 

Making noise like it revs up but the car doesn't respond

 

I'm researching now how to learn how check everything you just asked me because I am car illiterate, but in the meantime I am going to the mechanic that did the work to demand that he at least honors his warrantee and fix whatever he obviously did incorrectly. Hopefully that goes over well lol. Thanks for the quick response!

 

I also just noticed that even though the car has just been sitting there it went from half a tank of gas yesterday to a little more than a quarter tank today. Have not driven it one bit in the past day, and I don't see anything leaking on the floor either....

 

my gas gauge drops much faster from 1/2 to 1/4 tank than when the gas tank is full, so maybe its a gauge-related thin -- but if the car is new to you recommend runing briefly then examining entire fuel line from carb back to eliminate possibility of a leak.

 

If the motor's rpms are increasing but it's not responding, it could be transmission related. Check your trans fluid level right away. Note the color of the fluid.

It's normal for the gas guage to do funky things, especially with age and infrequent use.

 

Just managed to check the transmission fluid right before it started raining, and it was VERY dark brown. From what I understand I think I was supposed to see red fluid?

 

The last 1/2 a tank of gas always goes quicker than the first 1/2 - murphy's law!

Yes, fluid should be red - dark brown could indicate time for a rebuild - does it also smell bad, like burnt smell?

Remember, tranny fluid gets checked when hot and car running.

Brown burnt-smelling fluid is a definite sign of rebuild time - the clutches slip from wear, and the fluid begins to burn from the increased heat associated with slipping clutches, thus turning it brown. More 'slippage' means less transmission response from increased accelleration.

DO NOT CHANGE THE FLUID - it's quite possible that changing the fluid could mean a non-moving car afterwards. The material wears off over time, and these particles in the fluid act as a friction additive - changing the fluid now means losing all those particles, thus more slipping could occur since the particles (which help to retain grip) are gone.

And, this sounds like your problem - tranny going out. I misread earlier about the engine revving fine but car not accellerating - it does sound like your tranny is slipping now that I reread everything. I wouldn't venture too far from the house in the car, tranny might give out tomorrow, or might slip it's way through another month - no way to know until it's too late.

Tranny rebuild can be anywhere from $600 to over $1200 - depends on the shop and what they do. $1000 seems to be a fair cost at most shops. I got mine done for $500 - I was lucky and found a shop guy that rebuilds on the side at home, and he did a great rebuild with parts I requested.

If the car is needed quickly, but cash too tight for a rebuild, look at a used unit and swap - around here I can get used take-outs with 90 day warranty for around $300. Warranty doesn't mean it's been tested to be good, just means they will replace it if it doesn't last 90 days - labor is YOUR problem with this type of warranty. But a swap can be done in the driveway in a day by yourself with appropriate jack, stands, and a handful of long rachet extensions to get to the top two bellhousing bolts.

 

you said you took the car to a mechanic and it was just hard to start when you got it.So would the car run correct at speed on the way to the shop?If so have him fix his problem.if not then you had a hard start issue and another issue ie trans maybe.