Just purchased my GN and am having all kinds of problems but my new issue is vehicle hesitation.
When I accelerate to about 3000 RPM's and the turbo kicks in the car jerks and hesistates really really bad!!
Does this sound like a major headache or more less a common problem? My mechanic thinks there's a bad oxygen senser and clogged fuel filter??
Your suggestions will be appreciated....
A clogged fuel filter is a possiblity. I doubt the O2 sensor is the cause here.
I would suggest looking carefully for leaks in the entire intake tract. Especially after the turbo. If the amount of air the MAF (Mass Air Flow) sensor sees isn't what's really getting into the engine, what you describe can happen.
A bad MAF is also a possibility.
This mechanic sounds like he's sort of grasping at straws. You might want to find someone more familiar with these cars, or start studying up on the way they work. Either way, I would suggest considering the purchase of a scan tool so you can read and analyze data about what the car is doing. Well worth the investment!
It's probably a good idea to do the Spring Cleaning and the IAC Reset procedure as a good start.
Then you have a solid baseline to start your trouble shooting.
Just how much does the MAF sensor run in case this is what the problem is?
So in your opinion, this doesn't sound like a major deal....
I failed to mention that before I brought the car into the shop for repair, the GN was leaking, no not just leaking, pouring transmision fluid right from pan like water. The shop observed the same thing but they said the leak could be coming from the front pump; needless to say, they will need to pull the trans pan to determine if the converter and pump is the culprit or if the car just needs to be re-sealed. If any event, could this problem be related to why the car hesistates so bad when pushed to 3000 RPM's or could that be as stated above a different issue altogether....
TODD DEFINITELY INVEST IN A SCANTOOL THE MAF IS ABOUT $80.00
I recently purchased a 84 GN and the car runs pretty well. I have a problem though when the car is warm (like after being on the expressway for an hour or so), at idle the engine revs up a few rpms and when you try to go the engine trys to stall and will stall. Then when you try to restart it will just turn over and over. I have found that when you let the engine cool off for an hour or so it will start up and run fine. There are times though when you may be at a intersection it will stall and you have to unplug the eletric fuel pump to restart?? Is this just a cooling problem? Thank for any help. James
Todd: Can't see the transmission being the cause of the hesitation. MAF units are not available from GM any longer, and remanufactured ones in the aftermarket are hit-and-miss on quality. Many use the LT1 MAF and the Translator unit.
James: You may also have a bad MAF. I can't see how unplugging the fuel pump would help start your car. It obviously needs to be running for the engine to run. I'm assuming you reconnect it at some point before starting? This is another case where access to a scan tool would really help diagnose the problem.
How long has the fuel pump been on the car? I have heard that a pump on it's way out will sometimes quit pumping when it gets hot, & then once it cools down, will run again. If the pump hasn't been changed, you may want to look at that as being a possible solution. Good luck.
I actually start the car with the fuel pump unplugged, once it finally starts I have to run back and plug it up again. It is as though the system is delivering too much fuel and flooding out. That is the reason that I unplug it. The fuel pump was changed by the original owner within the past couple of years. I ausume that when a MAF is referred to, that is Mass Air Flow sensor? I also have a 91 Century, and it starts very easy. the 84 GN sometimes needs to spin over several times before it will start (usually hot). How do I test the MAF and what is the range it should be in to perform properly?
Thanks, James
I recently purchased an 87 GN.Found out it needed an engine rebuild and am now looking for a cam. I intend to keep it mostly stock , other than a stage 2 chip and mild porting on the heads. I was looking at roller cams, but seems the expense and amount of work is high and the problems of getting through inspection may be a problem. What is the best selection for a good streetable aggresive flat tappet cam?
Greetings,
I recently purchased a 1987 Grand National. When I was checking the engine I noticed that the belt was only making contact with half of the power steering pulley. Is this right? Or is there a wrong power steering pump installed?
I recently purchased a 1987 buick gn as well, im looking into a serious engine rebuild but i want to soup it up just a bit, im looking a good camshaft, heads, and pushrods setup. Also what are
the better pushrods out there, and are comp cams really worth the expense? Also what are the difference between champion heads and regular stock heads? WHat are some good parts stores in the USA I can use and be referred to?
At the risk of being negative....these cars will run well into the 11's with stock short blocks. Unless the car is already at 11.5 or so, you might stick with stock configuration and save yourself some potential grief until you know a bit more about combinations and so in order to be sure you end up with what you want.....
These cars are a bit different from Chevies and Fords when it comes to performance enhancements.
i just rebuilt the engine in my 86 GN at the shop at school and it runs great except when it idles. It idles fine but it hops around alot, can anyone help me out?
Not sure why everyone keeps stringing new questions into the same thread, but...
For the belt question (is that really an engine mechanicals question?), yes - only the 'back' of the belt should be in contact with that pulley. These cars came with a belt routing diagram on the core support. Though mine did not, and I know of one car with two of them, so anything is possible...
For the recent question: Can you be more specific than 'hops around alot'? Is the motor physically moving and seems to be out of balance? Is it misfiring?
Its very easy to get the cam sensor to be 180 degrees off, thus causing poor fuel flow particularly at idle.
In the future, I'd suggest those using the board post individual questions as new topics to avoid confusions in answering them.
Hello to all TR lovers. I am new at this so your help is appreciated. I live in Toronto, Can. and will be putting alot of work into my car over the winter during storage. Have a ton of questions for then, but for now. I'm freezing!!! My car no longer blow's hot air. Heater core? If so how do I replace it?
http://www.gnttype.org/techarea/techpage.html
http://www.gnttype.org/techarea/airconditioning/acpage.html
Thanks Ken. I see your name all over the place on this site. Glad you haven't gotten sick of " dumb questions " from us begginers.
It could possibly be missing, it shakes from left to right idling in park, but runs smooth as silk when it is being driven. I think i might not have torqued the balancer bolts down enought, ill go do that and get back to ya. Sorry for the beginner questions. There is the driver's side crack, but i dont see how that would cause it. There is also a small oil leak coming down from the bottom of the oil filter adapter. just small drips, its just been bothering me. I did replace the oil pump. ALso is the poston exhaust manifold (driver, passenger, and crossover) a good buy? Is there something better. I checked out atr and thats a pretty nice system. thanks
I blew a head gasket and have decided to embark on changing it myself. Removing the accesories from the front has been quite a chore so far. I started yesterday and I feel like I am in shop class in High School...So far I have removed the turbo, alternator, power steering and valve covers. My question is how does it go back together? LOL, hope to get car back together soon, still haven't got the heads yet to change the gaskets, hopefully today. Does anyone have a service manual they can send via ZIP.file?
Thanks
James