New GN Owner - Few Questions after long searches

[T66Typhoon]

I have a few questions.. the first should be a simple one... what is the stock turbo on an '87 GN... TA60?

The car was overboosting.. so I checked the boost control solenoid and it does not appear to be hooked up correctly.. or at all. Does anyone have a diagram from the service manual, etc. showing the correct way for it to be hooked up. The car was burying the boost gage when I got it... I have it just plumbed from the compressor housing to the actuator for safety sake, just on the actuator it is making about 10 psi, so safe for now.

Last question, how accurate is the stock tach? The car has 187,000 on it, when you stand on it.. the tach goes to 6000 and then shifts.. on the 1-2 shift and the 2-3 shft it never goes below redline on the stock tach... the car is obviously shifting and running though the next gear and then shifting.. is this a common problem...? Also when cruising in 4th it sits at about 4-4200, also seems high.. I know the obvious thing to do is to buy some sort of scanning software and check it, but I am not sure if I am keeping the car, etc.

TIA for the assistance.. this car is fun so far... I did ALL of the spring cleaning items on gnttype.org today....

 

[DJay]

Since I'm as new as they come as well, I can't answer most of your questions. I can however say that my new scanmaster says at around 70-75 mph in 4th, she runs around 2400 RPMS. 4-4500 sounds REALLY high.

I know it's not worth $0.02 but I'd like to think its worth at LEAST $0.005.

 

[Chris Cornett]

Nick, first things first, get yourself a quality boost gauge. 10 PSI is the spring pressure, that is why you are getting that. Not sure in the plumbing, my car is not here now. Your tach is way off, which a lot are. Does the car have an upgraded fuel pump? It really needs one. I would also get a scanmaster ffor ease in tuning and maintenance.

 

[WakkoSS]

Ok...the factory tachs are largely useless. Ignore it. If you're overboosting, you've got a vacuum leak or an incorrectly hooked up vacuum line. The box on the passenger side valve cover has a port on it that looks like it's supposed to have a hose to it...it's not, resist the temptation to plug one in there. You should be running about 13psi with a stock, unmolested actuator.

What'd you pay for the car? What's the condition? Any aftermarket parts?

You definitely need to invest in a scan tool. If you're going to keep the car, get a DirectScan. If you're not, get a ScanMaster or Turbolink. TL is nice since it's usable on a few other cars and has some good information. SM is nice cause it's super easy to sell used. If you pay $250 for it new, you can probably get $225 for it used...so you pay $25 to use a SM for a month or two.

Give us some specifics and pictures of the car, we'll attempt to help you fix it up, diagnose it, or decide to find another TR.

 

[T66Typhoon]

Well to start with.. the car is a 1987 GN.. I bought it from the original owner. It has had immaculate care taken of it mechanically. All the maintenance is documented, etc. The car is bone stock.

Like I said, yesterday I did, Belt, plugs, wires, oil, replaced all of the bulbs that were blow, cleaned the IC, checked vacuum lines, etc. I paid $1500 for the car.. the intent was to get it working well and then sell it.. I figure I can get 4k for it once I straigten everything up. The blue book on the car is around 6500.

I already have a boost gage for it. The car being completely stock I am not sure that I want to put ANY visible aftermarket stuff on it. Like I said, I am probably just going to sell it. As far as the fuel pump, I went with a high pressure walbro from Ron Gregory on the Typhoon and will probably do the same on this.

Here is how the boost control solenoid was hooked up:

So I was assuming that the controller was hooked up right, just that the solenoid was bad. I don't think the WG was even opening as the car would peg the boost gage and then detonate like crazy. Now with 10 psi, of course no problem. The plan was just to use a MBC and run about 19 psi on pump gas, after the fuel pump and pressure regulator were upgraded.

That pretty much sucks about the tach.. I was afraid of that.. the dash in these things is about useless anyway. I don't want to put a big red neck tach in there.. so I will search around for some options.

Thanks again for the info.

 

[jastrckl]

Yeah that solenoid is hooked up right. Check those lines for leaks. replace them if there is -any- doubt. As for the restrictor in the Y, if it isn't there you'll underboost so I wouldn't worry about it much. Worry about leaks, a stuck wastegate, etc. For $1500 you got a HELL of a deal. That guy must've needed the money in a bad way.

 

[T66Typhoon]

Well the guy was not a mechanic, and he knew the car had a lot of mileage on it.

Like I said, WG is operating fine.. I hooked the outlet on the compressor directly to the WG actuator, 10 psi, so all if fine there. I will put the lines back on, but I did not see any leaks... I bought some line, so I will try to reinstall it and see, looks to me like the solenoid is shot though.

 

[Mustang 1]

Hello Nick! It would seem that you got a GREAT but on your GN! The pictures look great. I also have a 1987 and live in Knoxville and Mike is a member here and lives in Knoxville also. I can be reached at work at 865-927-7227 or by cell at 865-803-2555. Just ask for Bill. I have a spare wastegate solenoid if you want to try it. Have a greta day!

 

[VIN7]

Nick,

Those solenoids rarely go bad. Try blowing through one of the ports on the solenoid. Without an electrical signal to the solenoid it should be closed and not allow any air to pass through. If the vac lines are in bad shape they can swell and wreak havoc on boost control. Awesome deal though. I believe the stock turbo is a T3/T4 hybrid. TA60 would be about two steps up.

Mike

 

[T66Typhoon]

Hey guys... I knew there were some locals somewhere. I will check the boost controller again today.

I was thinking I would just put a manual boost controller on there just so I could runa bit more boost. I would like to get it back to "stock" running trim though.

I may take you up on trying that extra one you have.. I will check the one that is on there tonight.

Thanks

 

[1ARUNEM]

Don't completely rule out the solenoid.. My old GN developed an overboost problem.. New solenoid from my local dealer cured the it.. They do go bad at times...

Goodluck..!!

 

[WakkoSS]

Wow, 1500 bucks? What a deal! Car looks good...I'm sure with the help of the locals you'll get it cleaned up and running right in no time. When you get new centercaps, just get em from GM...they're stillavailable and cheap.

 

[T66Typhoon]

I will keep that in mind on the centers... yeah I did get a great price on it... he was asking $3500.. I walked in expecting to pay a little more, but this is where I ended up.

I figure the car will bring 3500 or 4000 ...

I have been driving it everyday since I bought it.. so it is running very well already.

 

[DJay]

someone once mentioned to me that the solenoid on the top of the charcoal canister behind the driver's side headlight is the same solenoid that the wastegate uses.

i dont know how reliable that information is, but might be worth switching them if they ARE the same.

 

[T66Typhoon]

I will give it a look when I get home.

Thanks