Hello everyone! I just bought a stock 87 GN from the original owner and I'm having serious problems, the biggest being my own ignorance. I've never experienced another GN and therefore don't know if mine is acting normal or not. First of all, how are these cars (stock) supposed to respond when you're at a dead stop and floor it. My GN doesn't do anything but slowly accelerate to 60mph in about 10-12 seconds! My boost seems to max out at 10-11 psi. Aren't they supposed to go up to 14 stock? My car has new plugs, wires, coil pack, MAF sensor, and a freshly rebuilt tranny. The car has 79k miles on it. What could be causing these symptoms? Also, If I floor it, the RPMs gets to 5k and just sticks there. I have to let off the gas to shift or wait about 5-7 seconds for it to finally shift, sometimes it doesn't even matter how long I wait -it just won't shift. The car has had about 300 miles put on it in the past 5 years and was sitting for about 6 months out of each year before I aquired it a couple weeks ago. I would really appreciate it if someone can tell me what the 87 GN unmodified is supposed to act like (I can't peel out or do anything fancy) and what is wrong with mine. One more thing I almost forgot!! What boost are you supposed to get at what RPMs. If my car is in park and I floor it to 5k, the boost goes to 3 or 4 pounds max. How long is it supposed to take to get to full boost? My car seems to max out at 10psi and takes a while to get there. Thanks for all the help guys!!
I would check the CAT,... and the air filter.
When I bought my car with 60k miles on it the CAT was almost totally plugged and the air filter looked like it had never been changed.
I was stuck with 7 - 9 psi and it shifted somewhat the same as you describe.
The air filter is new too -haven't checked the cat. By the way, I got some e-mails: When I say I'm flooring it, I mean at a streetlight and in drive. In park I rev it up to 5k by flooring it and then let off when it hits 5k -I'm not just flooring it forever in park as someone has seem to got that notion from my first post. In park, once it hits 5k, I'm at 3-4 pounds of boost -should it be higher? How do you launch with higher amounts of boost?? Thanks!
What are you reading the RPM with? If it is the stock tachometer, it is way off.
I'm reading it with a stock tach. Everything on the car is stock. Why do you think my tach is way off? Thanks!
You need to load the motor in drive and foot brake it to build boost so once you let off the brake, you should take off at around 8+ psi depending on your tires and brake quality.
It sounds like your turbo is hardly doing anything (definitely if it takes 10-12 secs to reach 60!), or you are simply not putting the boost into your motor. Check all the hoses on and around the turbo and intercooler. Man..there's so much to check - you should really try to find a fellow GN guy to help you out on this car, or pay a shop to help out. It can get expensive, but its part of the investment in the car. A guy who knows what to look for could probably isolate all of the car's problems in an afternoon.
You may need a new wastegate solenoid or actuator, fuel pump and fuel sock, fuel filter, vaccum lines, throttlebody and intercooler hoses and clamps, fuel pressure regulator, the new MAF you just got can be bad since they're all rebuilds, you could have a bad/broken turbo or broken fins on it, oil in the intercooler, restricted air filter or inlet, etc.
Dont mean to scare you, but there are a lot of things that *could* be wrong on that car. The shift problem sounds like the cable detent wasn't set right which makes me wonder how experienced the trans rebuilder is..which makes me wonder if he used ALL of your original tranny parts (valvebody), or just gave you one from a monte SS or something and put the wrong governor in, etc.
Lots to check Kevin..you need to find some help once you've tried everything to the best of your abilities. We're here to help, but with so many potential problems, and not being able to isolate them ourselves - it could get VERY expensive VERY quickly just throwing on parts that are unneeded.
By the way - just about ALL factory tachs are way off. They are completely untrustworthy..not even in the ballpark sometimes.
There are good tips here so far - try to work on as much as you feel comfortable with and try to find a buddy that knows GN's in your area. Where are you located?
You really should not rev it up in park, especially to 5k. You will not build much boost in park, as there is very little load on the motor. To launch with higher boost just hold the brake while you bring up the rpm's in drive.
Thanks for the tips so far! I'm located in Ft. Myers, Florida and will be at Keesler Air Force base in Mississippi in about two months. Any big GN guys in those areas? What kind of response should I be getting from my stock GN by flooring it from a dead stop at a light? Also, can a stock GN with nearly 80k miles on it handle power braking for a launch without damaging the car? Thanks for everything!
From a dead stop on a stock GN with stock tires you should start going until around 15mph then the turbo will start spooling and you should start to hear the tires breaking loose. By the time 1st gear is almost up, the tires should be spinning into 2nd gear. If the tires aren't spinning or at least bark into 2nd gear - the car is tired and needs it's diaper changed.
Man - i forgot how much fun stock tires are on these cars! Makes me wanna throw my stockers back on and see if I can get 'em to rip loose at 60mph. :P
Once the car is running right, you'll want drag radials to put all that power to the ground otherwise these things just beat regular street tires into oblivion. Ahhh..good times..
Loading the brake is fine as long as the car holds still while you're building boost. It's not harmful to anything but the rear brakes, and those are cheap to repair. It's a small price to pay to go fast in these beasts. Building boost by footbraking the car is *how* to launch a GN. Flooring from a dead stop if for V8's..our cars need to build boost 1st. Get sticky drag radials, and try launching at 8lbs boost off the line. You'll be smiling from ear to ear.
oops..forgot..
the only shop i know of in florida is Rick Harper's. I bought a lot of stuff from Rick - great guy. Here's a website to get a hold of him. They're in Ft. Lauderdale so it's not exactly right next door for you, but maybe someone that lives closer to you from this list knows of a closer place.?
http://www.harpersracing.com
Sounds like my car needs its diaper changed.
My tires do chirp into 2nd, but I think it is because the transmission shifts hard. They are Perrelis (sorry about spelling) -not drag radials. The car seems to accelerate faster if I gradually go down on the gas rather than floor it. Any explanation for this?? I was reading a previous posting about rough idling. My car idles consistantly at a grand, but that's on the stock tach. Is this ok? Every once in a while when I start it, it will jump to 2k and gradually go down to 1k. Does anyone know if there what the differences are between the American GNs and the ones that were shipped out to Canada (mine)? Thanks a million!!
Before the turbo kicks in - it's still a monster-puss V6. If you ever get the joy of driving a regular V6 regal, cutlass or something with a 3.8 - you'll then see how pathetic these motors are without turbos. I had the joy of having my wastegate arm pop off the turbo (lost my clip that holds it on)...hoooboy! Talk about a perfect time for the spectators to take bathroom break at the dragstrip..
I always attributed that to the load placed on the motor. Full throttle from a stop loads the non-torquey motor down so much it can't get out of it's own way fast enough. A slight hesitation gives time for the motor to get the initial shock of all that fuel dumped in burned, and out of the exhaust and change from the high vaccum state. V6's from the mid 80's arent known for ANY power off the line (or higher up either really), but the lack of low torque sure keeps the excitement to a minimum when ya just stomp on it. Add a 3600-lb sack of potatoes on the sucker, and that poor V6 poops its pants. Get on it gradually, and the load increases more gradually allowing time for the motor to keep up with the demand of moving a heavy object.
Of course - i could be 100% wrong, but thats how it was explained to me. Without the cheap comedy of course ;)
As a good general rule, the stock tach and boost gauge are wrong. I've heard that brand new they were ok but it doesn't take long for them to start to go south. Somebody explained it to me using a rubber band that you can stretch back and forth for only a certain amount of time before it gets weak. You can get it redone by Caspers Electronics. I usually just use a scantool when I really want to know what's going on.
As far as going better if you slowly put your foot into it, this is just a guess, but if the car is somewhat rich it can cause this. If you put your foot down then it tries to dump a nice amount of fuel down it's throat, which it needs once the turbo comes up but until it does it's just choking. My car used to put out two big flumes of black smoke and then watch out! Good luck.
I heard the Canadian ones say things like "Door's open Ay" and when you hit the pedal "Get outta the way hosers!" hehe, couldn't resist.
Keith,
I've got an 87 Canadian GN. It runs like a raped ape! Sound like you need to really fine someone close to you that knows how to tune it. You may need to put it on a scan tool (scanmaster, Turbo Link, etc.) to really see what's going on. Have you taken off the hose between the turbo outlet and the Intercooler to see if you can oil? Probably do. Either from the turbo or the valve cover breather hose. Do you blow smoke at WOT?
A few things off hand, reset your transmission pedal position cable, mine was out of tune and made my car shift wierd. Also your TPS.
I see you are in Ft. Myers... I'm just north of Tampa. Me and a few other GNs and T-Types are getting ready to do a Test n' Tune at Bradenton Dragway in the near future. That might be a good time to see what others have done and get some tips. Also, KDK Performance in Orlando, and Cal Hartline in Melbourne are also good places to take your GN.
Let me know if you need any help!
See my GN at...
www.dalehutchinson.com
Keith, i'm in Greenville, Mississippi. Not sure how far it is from where you will be stationed but we race here every Saturday night till midnight. QTR mile "street racing". As many passes as you wanna make! Race who u want or solo. Sundays are 1/8th mile bracket racing(for money). Let me know if you wanna come race/test/tune. Will put you up for a weekend. Take care, Jay.