Looking at buying a 90 GP Turbo ASC McLaren

[carsofchaos]

Hi All,

Had a lot of Pontiacs, but never a 90 GPT McLaren. I have the opportunity to buy one that looks to be in good shape as far as body and interior, but there's a catch (always is, isn't there?). So the car in question had a small electrical fire under the dash. This has caused almost everything electrical on the car to not work (dash gauges, windows, seats....everything). While the visual damage isn't too bad, my big concern is how to fix this. The car still runs and drives (though it needs brakes and a few other things to be roadable), and I've been doing some research on how to fix this. A few guys have said this is not that big of a deal, just swap out the wiring harness for one form another GP 89-90 and all should be good. Others have said for me to avoid this car like the plague. My buy-in price is quite low. Any thoughts/opinions/ideas would be greatly appreciated.

Thanks,

Keith

[l67ss]

Hate to pry, but how cheap is cheap? What some people think is cheap is actually a rape me price. It all depends on how much work you wanna do. Are you gonna go custom or factory stock? A lot of time in an electrical the components end up with damage too.

Hi All,

Had a lot of Pontiacs, but never a 90 GPT McLaren. I have the opportunity to buy one that looks to be in good shape as far as body and interior, but there's a catch (always is, isn't there?). So the car in question had a small electrical fire under the dash. This has caused almost everything electrical on the car to not work (dash gauges, windows, seats....everything). While the visual damage isn't too bad, my big concern is how to fix this. The car still runs and drives (though it needs brakes and a few other things to be roadable), and I've been doing some research on how to fix this. A few guys have said this is not that big of a deal, just swap out the wiring harness for one form another GP 89-90 and all should be good. Others have said for me to avoid this car like the plague. My buy-in price is quite low. Any thoughts/opinions/ideas would be greatly appreciated.

Thanks,

Keith

[l67ss]

Oh btw welcome to the site

[Heartbeat1991]

That price is not low. It's about double or more what its worth. The brakes alone could cost $1500 for a new master cylinder. The dash wiring isn't completely interchangeable with other GPs. I am not sure what's involved in the swap. Just getting this car road-worthy and electrical components fixed could potentially cost a bunch. Unless you've either negotiated him way down on the $2000 asking price, or you don't mind throwing a ton of money at it, it's probably not worth it. It's fixable. But you have to decide if you're ready to lose money on it and just have it for yourself as a toy.

 

For reference, I recently bought one for less money that needed less work. And I already had quite a few parts for it. I have spent about $500 in parts thus far.

[carsofchaos]

I hear you. I wouldn't pay anywhere near the asking price. I looked at the car in person and I wouldn't go over $1k. Also he did mention that something was "wrong" with the master cylinder, that the diaphragm was no good, something along those lines. I was shocked when I saw one for sale online for like $1500! Thought it was a mis-type.....guess not. Interesting about the wiring swap. Like I said I've had some people tell me they change over with the other GPs from that year, others said "no".

[Psych0matt]

I guess I'm either tired or I can't find it, but what's the asking price? Basically, if it runs and drives it's worth around 1k. If it needs repairs to be ready for the road, I'd say closer to $500

[l67ss]

Think asking price is 2k

I guess I'm either tired or I can't find it, but what's the asking price? Basically, if it runs and drives it's worth around 1k. If it needs repairs to be ready for the road, I'd say closer to $500

[runt]

Honestly if it is a PMIII problem those are VERY hard to find. We have a user here who is doing some repair to them but I'm not exactly sure what.

 

As exciting as a TGP is I think you should wait to find a better condition one.

[White93z34]

2k for a car that needs a bunch of electrical repair..... rest of it better be MINT.

 

As for PMIII if you are pulling the dash to replace wiring harnesses you could head off ever fixing the PMIII and swap the firewall plate and put standard vacuum brakes in the car.

 

But lets be honest at the end of the day decent TGPs can be had for that without the electrical damage.

 

link to the advertisement?

[carsofchaos]

Hi Guys,

 

Thanks for all this info. The other main thing that's scaring me is the Master Cylinder. The guy said "the brakes don't work...there's something wrong with the master cylinder". Okay I thought, not a biggie, until I found one for sale for $1500. Seriously? $1500 for a master cylinder? I did look at this car in person, it's in okay shape I'd say a 6.5 out of 10. Here is a link to the ad, he's at $2k but obviously I wouldn't buy it for nearly that much. I think I've kinda already decided to just wait until a nicer one comes along.

 

http://newyork.craigslist.org/wch/cto/4231948808.html

[Euro]

Ha, I'm on that topic on the FB group. Welcome, you'll get all your answers here!

[White93z34]

Yeah the brakes on those can be a bit of a bastard. It was a early attempt at a compact ABS master cylinder. I've had my rounds with them and more or less have a reliable setup now.

 

The problems with them range from:

Rear pump housing cracks/leaks

Accumulator ball depleted (wear item that pretty much no one has ever changed in the cars 24 years)

Pump motor relay bad

or pressure switch bad

 

The housings I don't see broken that much

the Accumulators can be had new for about $130

The relays are no longer available. However I just modified/rebuilt a bad one this spring and ran it all summer with no problems

The pressure switches are also no longer available, I've been on and off again working on a solution to that, nothing yet

 

Now the unit itself can be rebuilt by SIA electronics but they cannot get any of the above mentioned parts and you'll have to send yours in as they don't keep cores anymore.

 

It also *really* helps to have a Tech1 or equivalent scan-tool to diagnose this system.

[Heartbeat1991]

http://newyork.craigslist.org/wch/cto/4231948808.html

[Heartbeat1991]

I wouldn't pay more than $500 for it. He could keep the Cavalier. I am not sure about the wiring, as far as what cars you could get it from. My concerns would be the HUD and the Boost gauge working. I'm sure it could be done. That's one hell of a lot of work. The brake fix is a lot of work, and could be very costly.

[Psych0matt]

$500 tops

[carsofchaos]

Yep I'm going to pass on this one. I'll keep looking. What do you guys think these are worth in really good to showroom condition? I never see these for sale, but I did see one back in the summer in my hometown of Billings, MT that was a "showroom condition" car they were asking $12,000 for it.

[Heartbeat1991]

It varies all over the place. There is another one in NY right now in nice shape for $4500. I know of another one in very nice shape in NC for $8500. They pop up on here from time to time. I have my eyes on another one and will likely sell the one I have or the one I am looking at. Not sure yet. For me, I prefer to buy ones that need work and bring them back to life. I tossed around the dash fire one, but he's way too high on the price for what it needs.