I'm driving down the road and the car is running great!! All of a sudden, the car won't go past 2000rpm and I get a code 34(high voltage, low vacuum). Now, I've replaced all the sensors(including MAF), new vacuum lines, cleaned and polished the throttle body and cleaned the plenum, timing is on the money, TPS and IAC are set by the book, new air filter, new PCV valve, and I think thats it. I have removed the smog pump, charcoal canister, and the EGR lines that run across exhaust manifold. I also replaced the relays for the MAF and Fuel Pump. After replacing all this, what do you guys think?

oh! this is on a 1986 Trans Am LB9 w/auto.
Any help on this would be much appreciated.

 

There is a TSB out for 86's for the computer chip, I cant remember the symptoms but MAF related sounds right to me. Check that first, Vader has the bad prom part number listed in a post of his somewheres, you can do a search and find it.

 

thanks.. I'll do a search for bad prom then

 

The SB is for false code 34, cold drive away problems, torque converter lock up and Idling too low.

~M~

 

The car also has a tendency to have a variable idle when cold but after she warms up, it smooths out.

 

For all the info on the bugged prom check it out here.
My question is why does it only affect firebirds? I though both camaros and birds had the same computers and chips....

 

It does affect both Camaros (what I have) and firebirds, they may have had a SB for each car for the same chip though.

~M~

 

Thanks for posting the link, I'll be pulling my comp out today to see which chip it does have. with there being a SB out on it, do you think Pontiac might replace it at no charge seeing how it's GM's fault for creating a bad chip?

 

Heh, no they won't replace it for free, I tried it too. They said it isn't a recall, just a bullitin. Cheap bustards.

~M~

 

Hey,

I

I just threw out a 86 ECM too. damn, I woulda shipped it to you..
I don't normally toss this stuff, but I was making room for 2 new cars I'm buying/stripping this week.


-- Joe

 

ACK! Don't do that I'm looking for 165 ECM for a possible swap.

If you want to throw them out...throw one my way.

~M~

 

Unless i have a complete TPI setup, I don't get any money for them.. noone pays for parts anymore

-- Joe

 

I'd buy it, I'm leaning towards replacing my 870 with a 165 ECM, since I haven't been able to find much on burning an 870 prom.


~M~

 

hey guys, I checked out the prom and computer in the car. the prom is a 3587 and it's a refurbished GM computer. Something else that threw me off was that there is a yellow box that is attached to the comps case. It says that it's the Spark control module? I'll take pictures of it later in the week when I can get ahold of my brother digital camera.

 

Well, I didn't get ahold of my brothers camera but I did get fed up with it's problems and finally replaced the computer(not the prom). WOW!!!!! WHAT A DIFFERENCE!!!!! All the problems that I was having just disappeared!

Before, I was never able to light the tires up unless the road was wet or I was in a slick parking lot and powerbraking. All I have to do now is step on the gas and she spins 1st and breaks loose in 2nd with an auto! Before I got my butt kicked by a STOCK 1990 Ford Probe V6 w/200,000+ miles. When I mean getting beat, I mean I might as well just sit still while the probe walks away!

Now I'm ready to do some more mods. I found a 400ci sb w/ a 4-bolt main that I will hopefully be purchasing in a couple of weeks and will be in the process of other major upgrades from there.

I want to thank all you guys that have helped me out with this issue. If it wasn't for you guys, she would have been sold and I would be driving a 1989 Mercury Cougar XR7(supercharged V6 w/5-speed). Because you have helped me out, you all saved me from switching to the darkside.

I will be taking her to Dinwiddie(Virginia Motorsports Complex) to see what she runs. I'm not going to expect miracles but I want to see what she does stock and where I end up after the mods. I'll post the slips on my website, www.hrhosts.com/slo86ta and will create a page to list any mods from now on.

Once again, thank you SOOOO much!