1991 Turbo Grand Prix... motor

[Turbo6000se]

Hello everyone, new guy here with some questions.

I have a project I have been working on for way too long and have come close to giving up one many times. It now seems to be finally working out but I need some answers first and I'm hoping someone here can help.

I have a 1991 Turbo Grand Prix motor and tranny both rebuilt with only about 50 to 60 miles on them. These two reside inside a 1987 Pontiac 6000 S/E wagon. I had this engine rebuild and swap done professionally back in '08 but the car never ran right and the guy closed shop, so I have spent the past 4 years or so trying to find someone who can work on this thing before I give up and crush it! I stored it for a few years too. Anyhow, I found a good place and they just did some work on it to get it running and without any tuning it put down 191hp at the wheels. Now they are in the process of getting a chip made for it but need some information on the cam that was used. The only thing the guy that put it together told me back in '08 was that it was a little more aggressive than stock. Never gave me a name of the manufacturer, grind, etc.. The guys tuning it need that. Any of you guys know of any manufacturer who made cams for these motors? Summit doesn't have any, Comp doesn't make any. I was all excited about this project back then, but after paying a good amount of cash just to drive a car home that stalled every 2 miles, I was not happy and almost gave up and took it to the junk yard. This is it's last chance.. Someone please help me save it from the crusher.

Thanks!

[WrathOfSocrus]

I'm no tuning expert, but the computer doesn't know what engine it is controlling, only what the sensors tell it. If he used a 'slightly more aggressive' cam, it was probably something like the Edelbrock or perhaps a Comp cam. Without knowing or taking the cam out and inspecting it then it is pure speculation. I would ask people here or try the WOT-Tech store (banner near the top that is invisible for a few seconds during its cycling) and find someone who knows these engines to straighten out your tune.

Also, are there any particular circumstances while driving that make it prone to stalling? If there is something physically wrong, like a vacuum leak or faulty fuel pressure regulator, tuning wont fix it.

Since there are wagon fans around here, and you speak of a turbo wagon, I have to say it - Pics or ban!

Welcome to the site!

[Turbo6000se]

Actually, today I found a few examples of cams that are sold for those motors and I took the specs to the guys working on it. Hopefully it will help determine what's in there, at least come close to it. As far as the stalling, after I got it back the first time and it kept stalling, I spent months looking for a mechanic who would work on it. I finally found a guy who went through it and he found it had tons of vacuum leaks on the intake, the hoses, you name it - it was sucking air in all the wrong places. So he sealed all of those up and then I was at least able to drive it without stalling at every red light. But it still ran like a pig and I didn't want to damage it by driving it so I parked it for a few years. Now it's driveable but hesitates a bit when you first step on the gas, then it's happy. It also has a few lean spots throughout the rev band that they want to correct. Also the speedometer which was working just fine, didn't work when I got it back.. Two new gauge clusters later - the guy who tracked down all the vacuum leaks discovered that the speedo wasn't getting a signal from the ECM any more. So now that has to be corrected as well. She needs new struts, and the tires dry rotted from sitting all that time. The paint on the roof also has taken a turn for the worse in the last 2 years or so. Other than that, the interior still looks pretty much brand new and everything except one window motor works - even the ERC! It now has an intercooler in the lower air dam area beneath the front bumper. Half of it is visible - I wish it was hidden but, it doesn't look bad. Here's one picture, I hope it comes up. I'll post more when I get it back.

[carbon]

Awesome... I had a silver '84 Olds Cutlass Cruiser wagon in college. Yours looks to be a heck of a lot more fun than the Iron Duke and 3 speed auto mine had. My favorite thing about that car was the full rally cluster it had in it, even if the tach went orange at 4500RPM... LOL

Try and figure out what ECM is running the engine and then ask some questions in the Tuning section of the forum. There have to be some connections you can make on this site in Colorado.

[timg]

Before trying to tune it, make sure everything is 100% mechanically. If there are any other lingering mechanical issues like those vacuum leaks, it will make it impossible to tune correctly. Since it's no longer close to stock, your best bet is to find someone local doing OBD1 GM tuning (or learn how to do it yourself). I've never been a big fan of tuning modified cars over the internet. It's possible, but it requires you to make a significant investment of time and hardware (to enable data logging). If you're interested in tuning and don't mind investing the effort it takes to get multiple sets of data logs, internet tuning can work well. If you just want it to work, use these forums to seek out someone else who can tune it in person.

Tim

[Turbo6000se]

Thanks for the post Tim,
It is being tuned by a good shop and they have the data logs etc.. They did a base line run on the dyno to see what it was doing and now they will tune according to those results. They went over it beforehand as well and made sure that it was in good mechanical order before doing anything. The motor and tranny are fresh rebuilds with less than 60 miles on them, and for having the wrong chip in the ECM, it drives fairly nice. But I'm sure with the correct chip, it will be much better. I didn't want to damage a freshly rebuilt motor by driving it lean or anything so, that's why I parked it for several years. Now that I found someone that can get it running properly, I'm pretty excited.

[Turbo6000se]

Carbon,

The ECM on the car is the under-dash version of the ECM in the Grand Prix. Same part number actually. The chip is different though and I believe the harness connectors are different on the GP too.

[carbon]

Now that I found someone that can get it running properly, I'm pretty excited.

That'll be fun... talk about a sleeper My wagon had 92HP, yours will have well over 200HP. Kinda makes me wish I still had it to do a swap on...