i just got a 89 iroc for my birthday
it dident make it home
every time i went to excellerate it would bog down
luckily i make it to the garage and the fuel filter was changed
thinking everything was fine leaving this dream car at the garage on my birthday the day i got it was not a easy thing to do
needless to say the same boging down thing is happening again after first half hour of driving
the cat/converter has never been changed since new
my thouht is that the cat is closing up when it gets too hot
is this possible?also it now is sitting because that half hour time is gone it bogs down right when i turn it over
and noticebly alot of engine shaking
any advise would be greatly appreciated
thanks mark:confused:

Mark,

Congratulations on the IROC and Happy Birthday!! :thumbsup: The third gen 1989 & 1990 IROC-Z models are the best for performance over their 1985-1987 and even 1988 brothers. IMHO, The 1988-1990 models look the best.


In 1989 Chevy went to a dual catalytic converter system for the IROC's. I think all 350's had them. I'm not sure about the 305's. I believe only some 305's had them.

In any case I would recommend getting a paperclip and checking for fault codes by jumping the a to b terminal where you would plug a scanner into. Or have someone with a scanner check for fault codes.

I have seen a Throttle position sensor, Coolant Temperature sensor and MAF (Mass Air Flow Sensor) cause these problems when the vehicle has been warmed up over a 1/2 hour. It is best not to guess on a 1989 model. It's not like a 1980 & earlier (before ECM's) where you can say it's a fuel pump or a carb, or a choke or a tune up. Those items were cheap. Especially on a 1969 where there are no electronics.

Bottom Line: I would take it to a reputable repair station or dealer in your area. It could be something simple or it could be something more costly. I would rather spend 1 hour of labor for diagnostic time and know what it is, as opposed to spending several hundreds in guessing.

Good Luck!!

SSG&H

Hey
Thanks for the advice,
I spent $508 for a new MAF today.
Dropped the car off at 9 am got it back at 5 pm and returned 5 minutes later
with the same issue.
the shop said they will look at all day tomorrow.
They said they had it out on the highway today and it was fine
When i took it back the mechanic took a ride with me and said "oh no it wasn't like this.."
So they diagnosed the wrong part and replaced it,
or diagnosed it right and did not install it right
so they want my car for another day. WHAT!?
They also said no charge, so i guess so
if not, do you think i should get my money back?
Now when i step on the gas it just wont kick in,
the sound that normally comes out the exhaust sounds like its coming out the cat ,the oil pressure gauge goes up as i accellerate,theres still back pressure from the exhaust tips,it almost seems like some limitation or something
thanks
mark

So they diagnosed the wrong part and replaced it,
or diagnosed it right and did not install it right
so they want my car for another day. WHAT!?
They also said no charge, so i guess so
if not, do you think i should get my money back? markIt reads like you found an honest shop, good for you. The shop makes an offer like they made, they're good on ethics.

It will be interesting to read what they find. It is unfortunate to see your birthday present sitting there and not driving it. Kindda like having ice cream and not being able to eat it.

Have patience and see what the shop has to offer. Points for you taking tham for a drive and the car screwing up.