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Finally got my first TGP Project Car! I need some help? runs rough?


jongrappin
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A little background, I bought the car today. I just got it home on the Tailer. Its a 1990 Black, tan leather with moonroof. 141,000 and its in decent shape. The car is for the most part complete, there engine has a miss? and the tranny doesnt have a second or third gear. I was told it might be the crank sensor of the coil pack?? what causes these to miss? Also to sweeten the deal the guy included a complete tranny and engine(non-turbo) that runs good with 80K on them? Should I just swap the whole engine and tranny out? Or should i try it get the miss figured out? do you think it would matter if i was to keep the vehicle all numbers matching or swap the engine and trans since the milage?

Please help, any advice or comments please. I am debating if i want to fix this and keep it, sell it as it is?

 

I will post pictures tommorrow.

 

Thanks,

Jon

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get the TGP trans rebuilt. it would come out a much better project with a fresh 4T60HD.

 

numbers matching no but transmission matching yes.

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Missing on these engines is a road most TGP owners have been down. How long was the car sitting befor you got it? If it was long, did you start it with fresh high octane gas, or just whatever was in the tank? Have you ohm checked all 6 injectors? 12.1 and up is good, 12.0 is borderline, 11.9 and down is bad. Have you checked what type of spark each coil is putting out? Weak spark is just like no spark under compression. Have you replaced the spark plugs with the correct, and correctly gapped, spark plugs?

 

I think that about covers the biggest problems. Start with those and let us know!

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Thank you both for the advice. I will start with fresh gas and checking the spark and coils. how do i particularly test a coil/spark to be considered weak or strong other than visual? I will try to check the ohms on the injectors but i would rather not take the plenum off. Can i test these otherwise? I have not looked at the plugs yet, does it really matter to have specific plugs and gaps? also it it has some auto zone plugs on there that were new, will these do? other things to consider, it starts every time and runs but it idles high and also the gauges do not read correct, the rpm is pry double what it is suppose to? also to consider the kid i bought it from seemed to have some mechanical experience but little, and even less motivation. does the high idle or gauges reading wrong indicate a bad sensor or what?

 

Also the car doesn't shift into 2nd or third? is it possible its a vacuum line or simple or linkage? or have can i be sure the transmission is done for?

 

I will tear into it tomorrow and i will post pics for those who are interested or want to help.

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Make sure the plugs are gapped correctly. When i changed the ones in my park Ave last fall they were WAY off, whoever did them last must have just put them in and never checked the gap. Might be the same thing in your situation. The gauges reading incorrectly is completly normal for TGPs, there is a resistor on the back of the cluster that degrades over time and causes the tach and speed to read higher then they should. The boost gauge reads incorrect on most of them as well.

 

Oh and, :showpics:

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Good news! The car is running much better now. I checked the plugs and wires and found that only 3 of the plugs and wires were changes at some point in time and that one of the plugs was like new, never fired because of a wire was bad.

 

I replaced all plugs and wires. I used duralast wires, and autolite plugs because AC/Delco was not available, I gapped the plugs to .45. Are these plugs and wires decent?, is there anything I should know of them?

 

I disconnect the battery for a min to reset the computer. I then started the car and it ran a little rough for a few minutes and then it started to idle and run very smooth. Lol, there is still old gas in there, so it should be even better when I change that. :dance:

 

:think::think::think:

Next Issue, the engine idles and runs good. when i get on the gas it accelerates good and the turbo spools up well, then it shifts to second gear and turbo starts to boost real well again and then when it should shift to third the car then kicks..out of gear as if it was in neutral, it then free revs like its in neutral until you slow down to a speed where first or second gear kicks in...

 

Is my third gear shot? or could it be something easier such as a vacuum line or fuel cut? The original boost controller appears to be attached properly and all lines ran properly. should I bypass the stock boost controll and if so how?

 

Any ideas about the tranny issue? the kid that sold it to me said the second and third gear were shot but second seems to work fine, also he though the engine missing issue was a crank sensor or speed control sensor, lol it was a bad plug wire....

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I am no help with the tranny issues. I dont think the Vacuum modulator can do this, but maybe someone with more expertise can help more..

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[/b]

 

 

Sorry to hear that.

ha, I never used to have that attitude until the last year or two. I got my first one in 99. old black/grey/sunroof... still got it but it don't run, its getting put down sadly. lately everyone's tgp has been acting possessed it seems. all mine have been unhappy lately. My buddy Jim just got his back on the road. it sat for a good year under a car cover.

 

they were a dime a dozen for a while there. but now they are few and far between it seems lately. just in like the last year or so.

 

In my experience, they are good reliable transportation. that first one I put like 80k on it. got up to 194k or so before I gave up on it.

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Hello everyone Here are the pictures I had taken on April 22, 2010 This is before I did any work to it other than washing it, and airing the tires up....

 

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So after taking a week to decide what I wanted to do, I decided I am going to do a full restore on this car, tt is all there!

:laugh::laugh::laugh:

 

To start the restore, I decided to pull the engine and transmission out of the top of the car. It had taken friend and myself approximately 3 hours to pull them. After that I disconnected the transmission as well as the cross-over pipe and turbo. I plan to crack the transmission open tomorrow to investigate the issue.

 

Other concerns, Does any one know have i can test all my sensors in the engine while its out, I dont know what everything should ohm out to??

Is there anything that i should address while the engine and transmission are out of the car?

Also is there any way to test all the A/C components while the engine is out. I want this ready to go for the summer :dance:

 

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More questions to consider:

 

How can I tell if the Crossover pipe has been repaired or if it is currently cracked or just good to go. I did not notice any exhaust leaks when the car was running.

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Both rear quarter panels dented in... ouch! This one is going to take a good amount of work!

 

If the exhaust crossover is still the factory unit, it is very likely leaking and should be R&R'd. Factory x-overs have a heat shield on them and accordion style flex bellows on them. Here's a factory one with the heat shield removed:

TGP020.jpg

 

Ones that have been redone look like this... (this is my refurbished x-over for reference):

TGP002.jpg

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Post up the VIN number + build date for me when you get a chance. Send me a private message(click my user name, then the "private message" option that shows up there) if you don't want to post it publicly for whatever reason. I'm compiling a database/registry for these cars. The build date will be listed on the "ASC" sticker on the driver's door(jamb area) if the sticker is still there.

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Hello everyone, I am back and i want to get to all of your questions and comments. I'm in Michigan and my name is jon.

 

I have started some major updates and I need your guys help!

 

My VIN is 1G5WP14V8LF225101 , I will look at the build date tomorrow

 

Updates!

I Just had the original transmission completely gone over by a professional that had his own transmission shop for 25 years, and Pontiac's are pretty common around Bay City, Michigan.

 

So what was the verdict on my transmission?

The third gear Skag? blew up and damaged the gear basket. Otherwise the transmission was in great shape. All of the special heat treated parts were in there and in excellent shape. all the gears and clutches looked excellent. The transmission appeared to never had been worked on before, but he said that he was surprised how good of condition everything was in. the clutches were all excellent, he also resurfaced them, the overdrive clutches were wore so we put in new ones. Also New Shift kit installed and a few other hardened parts were replaced as well as a few other goodies, Also bought a new torque converter. So all in all the transmission has been completely overhauled along with extras. The transmission is straped to the engine and they are handing together right now. I will drop them in the car in the morning. If you guys want me to check any casting numbers or anything please let me know before i drop it in.

 

as for the crossover pipe it seems to be stock with the heat shield on it. it seems good to go but i dont know??

 

and finally. I hope to have the engine in today, so that means the next step is paint!:dance: I have decided to do a complete restore of this car. So can you guys please tell me the part numbers of the front valance, the front driver fender, and the front driver fender molding thingy, (also what is this called). Please let me know the best places to find these parts. either new or used.

 

other thing is how can i figure out what my option codes are so i can put in a stock CD or tape player. Or i was thinking or putting a newer CD player in but i do not what to loose the steering wheel controls... does anyone know if they still have or what those things were that allowed you to tap a pioneer deck into the steering?

 

Also then the tuning? any recommendations on chips or hooking up a computer, where do I buy these new or used.

 

thanks for all the help, I apologize for asking some of what my be obvious answers but i am not familiar with the TGP, the special parts and where to get them?

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good to hear that your trans will be alright now. your crossover might be okay yet, but they all fail sooner then later. can you hear exhaust leaking in the engine bay? GOT2B GM is working on rebuilding them so he would be a good person to go to for a crossover.

 

http://www.compnine.com/vid.php?vin=1G5WP14V8LF225101 looks like your car initially had a cassette deck.

 

Also check your turbo oil return line, the inside of it might be pretty shot by now. I know mine is in the process of failing, but its not too bad yet.

 

Also one of the most common chips has been the old "Jeff M" chip, however those have not been made in a long time. I'm working on getting a dump of mine so new ones can be made from it.

 

if your oil pan gasket looks leaky replace it now. its a pain with the engine out of the car, I can't imagine how bad it is with the engine in the car.

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All you need to make the steering wheel controls work with a aftermarket radio is a interface. Axxess makes one that thats easy to install and works with most cars and radios, its called a ASWC. You can prolly find one for $60-80 or so.

 

As far as the body panels go, i dont know any part numbers, but i doubt they can be found new anywhere. The valence especially you will have a hard time find a good one.

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hello I am in need of the gaskets the go on both side of the turbo. I cannot find them anywhere. any help?

 

Is the TGP front valance the same as the SE or LE model? or was it special??

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are you speaking x-over to turbo and turbo to downpipe gaskets? if so there is no gaskets needed for that.. 2 machined surfaces do not need gaskets and do not leak..:thumbsup:

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Is the TGP front valance the same as the SE or LE model? or was it special??

The valence panel was TGP specific for 1989-1990. You can however use one from a 1991-1993 Grand Prix with B4U bodywork.

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