87 GN having problems need Diagonstic Help

[nash87650]

Hey everyone,
I have an 87 GN and have been having problems with the car since I bought it.

I bought the car in June, after it had been sitting for 2 years, and when test driving everything seemed to be running fine. However as soon as I bought the car and drove it home the car started having problems.

When driving at a steady speed (about 35) the car seemed to sputter and stop and go as I was pressing the gas. The turbo boost I think was going crazy as well. Also, at times the tranny shifted kinda weird when it shifted to second or third gear. It's kind of like when your in manual and you shift gears too soon from 1st to 2nd gear.

I thought maybee a good fuel injector cleaner and a tune up might fix the problem and it seemed to work for a while. However recently the car has been doing the same type of thing but not as badly. Now it does it after I've been driving for a little while.

Also, now the brake light turns on while I'm driving.

I replaced a damaged master brake motor from the master brake system when I bought it so I don't know whats going on, but I do hear a humming noise from that area that won't go away. Not sure if that normal. The noise starts and then stops as your driving, and you can also feel it on the brake pedal.

I also checked underneath the hood and it has an oil leak on the hose that goes from the turbo to the intercooler.

Has anyone had these problems? Or can anyone help? I would greatly appreciate it.

Thanks

 

[TurboDave]

Your bucking and so forth under accleration is usually indicative of a bad MAF (if it does it under any kind of acceleration), or a bad coil/ignition module assembly (if it requires more throttle) like as in getting close to, or into boost.

As for the brake light, you probably replaced the wrong part by replacing the motor. The humming you're hearing is the motor running (too much) most likely because the accumulator (ball mounted on the side) has gone bad (most common problem).

DON'T CONTINUE DRIVING WITH THE BRAKE PROBLEM, you'll likely cause even more costly damage to the system.

 

[mikestertwo]

Your shifting problem is most likely a bad TCC solenoid in the transmission. It's cheap and easy to replace.

 

[MajorBoost]

Replace fuel filter(under car behind driver door). Next you may need to replace the fuel pump especially if it's the original.

 

[nash87650]

Anyone know of a good mechanic in the San Francisco Bay Area?

Thanks for the info guys.
Will check into that, next time i see my mechanic.

I tried driving it to my mechanic and from looking at it he told me it might be a bad EGR sensor and told me to do a couple of things to check it to see if it was bad. He told me next time i had the problem to park and turn off the car then stick a screw in the egr hose and then plug it back in and start the car again.
That was last week when the car used to drive pretty nicely through the city. Most of the problems were on the longer drives after I got back from about 30miles ther and another 30 back. Recently though the problems happened after I got about 10 miles away though.

Idle used to be good also at all times.

However recently, last Friday, I drove the car about a mile parked for an hour, then drove back. While driving back it got really bad. The car seemed like it was choking really bad as I was driving. Parked the car and the idle was bad, it would run then slow down for a second then go back. Turned the car on today to see if it still was idleing bad. Still does. Driving it home was bad, it seemed like every block the car would choke and then go.

I tried getting a hold of the mechanic who last looked at it but had no luck.

Does anyone know of a good Grand National mechanic in the san francisco bay area? Everyone I've tried talking to seems like they don't even know what kind of car it is.

Last, don't know if this matters but there's an oil leak on the hose that connects the turbo and intercooler. Checked the rest of the pipes as the go to the intake and they are all really dirty, very black an greasy and there was a small pool of oil inside of the hose that connects the intercooler to the pipe that goes to the intake.

Also, I believe the car has 44k miles from the carfax reports but can't be sure. The last owner had the car sitting in a garage untouched for two years. Got a complete tune up about 900 miles ago in June. Fuel Filter was really dirty.

 

[Junior Samples]

Theres a hose that runs from your pass side valve cover(front) to turbo. they sell a bypass kit. Its a breather to stick in its place and cap off the inlet at the turbo so its not sucking oil from valve train into the turbo...down into intercooler through the up pipe then into your motor which could be casue for most the problems your having.

pull intercooler and clean as well as pipes and ad bypass kit

 

[Clark6]

As Dave said above borrow,swap,buy another MASS AIR FLOW SENSOR or just go get the translator, harness & Lt-1 sensor from FULLTHROTTLESPEED.


Cheaper to swap but thats what MY problem was when i was having these issues.

Id still do a complete full fuel sytem change filters, even the sock one in the tank and up todate fuel pump.

I havent had to change the TCC solenoid in the trans but they do say it will make it buck & surge whan coming to a stop or taking off if i can remember.

Definately do the Maf sensor first though.

 

[Chuck Leeper]

My $.02...

Clark said: "Id still do a complete full fuel sytem change filters, even the sock one in the tank and up to date fuel pump".
I completely agree w/ that suggestion. A car that has been sitting for 2 yrs, and then started and driven, has likely pulled some NASTY gas, dirt, rust, and who knows what else, into the fuel system.
On car cleaning in this instance, is pretty much a waste of time and $$.
Start at the rear of the car, and:
1. Drop the tank, clean it, replace the pump and sock.
2. While the tank is down, CAREFULLY inspect the rubber hoses at the tank area. [Should be a shield over them, above the axle.]
3.When changing the fuel filter, disconnect the lines at the engine, and blow clean. Inspect the lines at the ft of the frame to be sure they are not kinked.
4. Add a hotwire kit from CASPERS.
5. Check the electrical system to be sure the voltage to the pump is correct.
AND: GOTO gnttype.org, and do a spring cleaning!
Also, of PRIME importance are some tools:
Fuel pressure gauge.
Scan tool.
VOM.
LOTS of patience..
The other guys have good suggestions..Heed them, and you'll have fun w/ your car.
Back under my rock...

 

[zeus87gn]

You're brake issue is of MAJOR importance.
As TurboDave said, STOP DRIVING THE VEHICLE before you run into a stationary object...like a KFC or a mustang.

The brake light is on because there is low pressure in your acc ball.
The humming is NOT normal. You should not hear the brake system at all.
Your killing your motor by overworking it.

You need to run the diagnostic tests before you go further.
Look here: Brake System
Get a good time piece and figure out your problem.
Most likely it is the acc ball, but you need to determine if you have any internal leaks. If you do, a new acc won't do you any good. All that time sitting, and guessing old black brake fluid isn't good for it.

Email me if you like. The PowerMaster is it's own animal....and discussion.

 

[nash87650]

Parts and Troubleshooting

Thanks Again for the info guys,
Just had my old mechanic take a look at it again and agreed that we should clean the tank, change the fuel pump, replace filter, and clean the injectors.

Will also troubleshoot the brake system.

As far as the bypass breather kit, I found one ebay:
eBay Motors: Buick Grand National PS Valve Cover Breather (item 230180107903 end time Oct-16-07 14:27:10 PDT)

Is this all I would need?

Also looked for a hotwire kit, but only found one on Jegs for an LT1-equipped car.

Will see if I can borrow MAF sensor from a buddy to check that as well.

Thanks again guys, I really appreciate all the help.
Will keep you posted.

 

[Chuck Leeper]

You..

Thanks Again for the info guys,
Just had my old mechanic take a look at it again and agreed that we should clean the tank, change the fuel pump, replace filter, and clean the injectors.

Will also troubleshoot the brake system.

As far as the bypass breather kit, I found one ebay:
eBay Motors: Buick Grand National PS Valve Cover Breather (item 230180107903 end time Oct-16-07 14:27:10 PDT)

Is this all I would need?

Also looked for a hotwire kit, but only found one on Jegs for an LT1-equipped car.

Will see if I can borrow MAF sensor from a buddy to check that as well.

Thanks again guys, I really appreciate all the help.
Will keep you posted.

put that stuff in "file 13", aka, the junk pile, and install the breather.
As for the hotwire kit:
Casper's Electronics

 

[nash87650]

Still having problems

Hey guys,
Just wanted to update you on the problems with my GN.

I ended up changing the fuel pump and sock, got a new fuel filter, cleaned the injectors and changed the Mass Air Flow Sensor as well as clean out the intercooler and pipes.

Unfortunately I'm still having the same problems, the Scan tool reads an error 33 and 34 or 32 and 33. MAP and MAF.

Also, the Service Engine light is on and the car still idles wierd and has that bad chocking problem.

Besides that, I rechecked the cleaned pipe from the intercooler to the intake after a short drive and It showed puddles of oil.

Any Advice???

 

[olds443]

Vortex Turbo Buick Performance
Go here or gntyype.org. You will find what all your codes mean.
I would also suggest maybe a trying another ecm and make sure your alternator is putting out full voltage. It's odd that you are having all these problems at the same time.
I know I had an alt go bad that showed alot of these symptoms too (btw, replace your belt if it's been on there awhile. They lose tension.)
I also had an ecm going out that did some funky things that would come and go. Then one day it just literraly went up in smoke.

 

[olds443]

As for a mechanic... try Mizzi's in Fairfield. I posted just the other day with his info. He is the best around here.