New '87 Owner:

[Tom R]

Hi Everyone,

I just picked up my first 1987 Grand National (t-tops) Monday. It has 58K, the original trans (bumped up to a 2004R SSR), engine and interior. The car was repainted and looks almost exceptional to me considering some minor flaws. Anyway, I have noticed a few problems I'm hoping to get some input about.

I drove the car home about 55 miles and was running about 2000-2200 cruising speed. When I exited the expy, the car stalled as I came to a stop. Restarted it in neutral and off again. Well, it happened several times within the next few blocks. I called the previous owner and he felt so upset he said he was returning my money and coming to get the car; he was embarassed. So he drives 60 miles to my home, apologizes and said he'd take the car back. I told him I called my mechanic and he thought it was something minor. To make a very long story much shorter, we traveled back to his home town plus 15 miles where we met a guy from a pro speed shop that had done some work on the car. He scanned the car for codes and checked everything and it checked fine. He even shifted gears, flipped the A/C on and off and still nothing. We leave after about 30 minutes and make it back about 1/3rd of the way home and it stalls three more times. WE go back to the guy and he talks with the previous owner and tells him he recently had the ECM replaced along with a new alternator and belt. Well, the guy winds up pulling a little rubber boot off what I think is the idle control valve and gives it a half turn. We leave and I make it home and have had no other stalling issues since. However, for the last two days, cold start up has the RPMs at 2000-2200 and it doesn't drop even when goosing the gas or shifting from Park. I shut the car off aftre a few minutes and restart and gues what...it idles at 1000. Any ideas?

The other issues are the A/C is the old R12 and blows warm. Do I have to convert it to R134a or can I recharge to R12? And at what cost if I don't do it myself?

Last, as I said the alternator, tensioner and a new belt was added. There is some loud sqealing from start up adn at idle but it settles just a bit but then more you get on it the sounds gets louder? My mechanic said it's probably the pullies and they weren't cleaned well enough before installing the belt. Any ideas?

Thanks for helping out a new very little but willing to learn G.N owner.

Oh, perhaps I should add that the car has a TE-44, and the other typical upgrades. The ECM has a 93 octane chip in it now. Thanks everyone.

 

[1986TR]

you are going to need a scan tool the "scan master" is a must what this guy turned is what people call the "idel screw" but its not really a idel screw. i suggest you read alot over at "gnttype.org" read the "quick reference" and then the "spring cleaning" and i cant stress this enough "SCAN TOOOL" but your in the right place!!!!!!

 

[bayareaturbo]

Get a scan master asap. You can find them here on the board used or one of the vendor will have them.

 

[Tom R]

There appears to be a scanmaster tool sitting on top of the radio dash. It's got a moroon face covered in black and is about the size of a deck of cards. It says scanmaster accross the top and near the bottom of the face it say something like O2/millivolts on the left and degrees retard on the right and there are little pins sticking out on each side. Is that what you're referring to as a scan toool?

 

[krom]

Thats it.

 

[Tom R]

I guess I've got some learning to do. Either that or I need to find a trustworthy G.N. specialist in the Chicagoland area.

 

[dsa87gn]

that little screw he turned is the idle air control (IAC). If you adjust that properly you may be Ok, since the problem you are describing, stalling when letting off, is commonly caused by out of spec IAC.

Since you have a scanmaster, you have all you need to get started:
go to Vortex Turbo Buick Performance , then basics on the left size. then IAC adjustment and read up. Good luck.

 

[bayareaturbo]

Do a search on scan master and you will find the readout what the car should be running and go from there.

 

[Junior Samples]

Any time you tinker with that screw (IAC) you must then adjust your TPS sensor..... Flip your scanmaster to TPS setting, with key on engine off your TPS should read anywhere from .40 to .44

Mine is at .42

turn scanmaster around on dash so you can read it from under the hood, loosen two screws on TPS on pass side of throttlebody, move it around slowly and note the readings on SM, once you get it at say .42, hold it and tighten screws



Your IAC counts with engine warm and at idle depends on what your car wants,
anywhere from 15 to 35

Mine is at 20

 

[nu2gn]

stalling.

hi there, congratulations on ur purchase, i had a stalling problem when i first bought my new gn in may, i had injector o-rings leaking and sucking alot of air, i heard goog things about a guy that they call boost doctor, his name is surej, he is south of chicago, if u got any questions,let me know, or send me a pm.

 

[djj624]

What chip is in the car? If factory that can be your problem as well. I had very similar problems as you describe when i got my GN and tried everything from mass air to fixing vac leaks to fuel pump and everything in between with no luck. Jumped into a TT chip and then it ran like a dream.

Just a thought.

 

[supramantrm]

belt

noise i recently had sounds like yours ,turns out my new belt was too big ,went to a GAtorback and it went away.
Stalling can sometimes be corrected thru the chip.Depends on what you have ?

 

[nwarky]

stalling issues

Tom,

One other thought on the car stalling when coming to a stop. Consider the possibility that your torque converter is not disengaging when coming to a stop which will cause the engine to bog down and stall (just like coming to a stop in a manual shift car and not letting out the clutch). Don't let this minor - and I do mean minor - glitch detract from your initial joy of purchasing this car.

Dean

 

[Tom R]

Thanks for all the replies everyone. It's a lot to take for a guy that knows little about these cars other than I always wanted one. I dropped the car off today to have the A/C changed from R12 to R134a. I addition, the radiator has a small leak on the driver's side. Will a stock repalcement do or should I invest in something else? I am not going to race the car. It's going to be my cruiser but I will step on it from time to time. The most significant problem, other than the noisey belt/pulley, is that on cold start-up the car stays at about 2000-2200 rpm even in gear. When I shut the car off and restart, it idles between 725-825. I'm not sure what to do there. Oh, and while the guy has my car, I asked him to check the compression and wires. Good idea?/?

nwarky, The trans was rebuilt two years ago and taken from the stock
2004R to a 2004R SSR by Jimmy's Transmissions in Mundeline, Illinois. How would one determine if this is a torque converter issue. From what I was told, Jimmy is top notch and the trans is good for up to 650 HP; not that that matters.

Supramantrm and djj624, The chip is the 93 octane installed in a new ECM.

When I get the car back Monday, I'll check the readings on the ScanMaster and see where I should be.

Thanks again for all the advice to a newbie; it's greatly appreciated. I will take the time to learn what I can so I ensure I give myself the best chance of keeping the car running as well as I can.

 

[TurboRegal84]

It is normal for the cars to idle up a little and then settle into a nice idle. You should not have to shut the car off to get the idle to go down sounds like the IAC is out of adjustment.

Reset the IAC sensor and TPS sensor as previously mentioned. These two small adjustments can really smooth out an idle and make the car run completely different.

 

[GN owner]

Do yourself a favor and get a TT chip for your combo and you won't regret it. I tried several chips for my car but the moment I installed a TT chip in the car it was like night and day.