Run problems - '87 GN

[psuog]

I have an '87 GN I bought new. 30,000 original, garage kept. dropped about 8K into it the last three years for parts and paint and am a bit frustrated with idle and run problems over the last few years. cranks and starts fine, idles quite high, then drops to a more normal idle, then almost stalls. I don't even try to put it in gear until it warms up a bit, just stalls if I do. lately, I also noticed what appears to be random hesitation and some apparent missing and/or weak performance. I have a digital dash with no aftermarket gauges so I can't tell what's going on with boost, temp, etc. no warning lights on dash, no codes in the original computer. gas mileage is also down 3-4 mpg.

the garage that's done most of the work is ESP Performance out of Pottstown, PA. they used to run a dual turbo white and blue '86 regal up until a few years ago.

new plugs, one step up injectors, 3 inch exhaust, heated O2 sensor, Kenne-Belle ram-air, ESP coil pack and performance chip. new plug wires, vacuum hoses, many similar items replaced.

any suggestions on what to check would be greatly appreciated.

 

[SS502]

I'd take it back to ESP Performance. Without a scan tool your going to be going in circles. Cam Sensor..Maf.. ECM..Vac. Leaks..ect. It could be a number of things and people will suggest things to try, but will it be the right one? Or invest in a scanmaster so you can at least get a starting point. Going to be hard to help without more info. Just my 2 cents.. lots of good people on this board that really know their stuff, so the more info the better.

 

[3-5.0]

No warning light or codes...hmmm. Would a header crack signal the check engine light or a code.

 

[PSID6]

I feel your pain,I can't bring myself to buy these babysitting computers and add ons like Scanmaster power logger translator pro etc.For the sole reason that some guys that have this stuff still can't figure out what's wrong with their cars. I think I am going to bite the bullet and buy a stand alone EFI system and bring the electronics into the 21st-century. My car has many of the same issues and is driving me insane! I don't mean to steal your thread but I guess I have to vent I am very frustrated also. I have waited almost 20 years to own one of these cars. But with all the trouble I've had thus far,it still puts a smile on my face every time I open the garage LOL.

 

[turb]

As pointed out above, it could be a number of things causing the problem. I chased a problem for a year before finally finding the cause. It was the cam sensor. Didn't show any codes and didn't show up in computer analysis. For my money, a check of the cam sensor is a must whenever your car starts to run bad. Why? It's easy quick and free and will at least rule out the sensor as the culprit if not identify it as the problem.
So, start the car. Then disconnect the cam sensor. Drive the car and see if it performs better. You must reconnect the sensor before starting the car again.

In my case the car ran normal with the sensor disconnected so I pulled the cap, cleaned it (only a tiny bit of dust in there that I could see) and the car runs like new again.

Good luck!

 

[GNONYX]

I feel your pain,I can't bring myself to buy these babysitting computers and add ons like Scanmaster power logger translator pro etc.For the sole reason that some guys that have this stuff still can't figure out what's wrong with their cars. I think I am going to bite the bullet and buy a stand alone EFI system and bring the electronics into the 21st-century. My car has many of the same issues and is driving me insane! I don't mean to steal your thread but I guess I have to vent I am very frustrated also. I have waited almost 20 years to own one of these cars. But with all the trouble I've had thus far,it still puts a smile on my face every time I open the garage LOL.

I think you're missing the point of what SS502 is trying to said, without at least a ScanMaster you can't troubleshoot any type of problem to which you are having now. Even if you change over to the 21st Century scan tool, it's still going to be call ScanMaster, Power-logger, etc.

Get a ScanMaster read the easy instruction, install the scan tool, idle the engine hot, write the numbers down and then give the reading numbers to board so other experience members can help and guide you to your present problem.

I myself was one like you with problems until one member told me to invest in a ScanMaster as a starting point to troubleshoot these cars.

 

[GNONYX]

As pointed out above, it could be a number of things causing the problem. I chased a problem for a year before finally finding the cause. It was the cam sensor. Didn't show any codes and didn't show up in computer analysis. For my money, a check of the cam sensor is a must whenever your car starts to run bad. Why? It's easy quick and free and will at least rule out the sensor as the culprit if not identify it as the problem.
So, start the car. Then disconnect the cam sensor. Drive the car and see if it performs better. You must reconnect the sensor before starting the car again.

In my case the car ran normal with the sensor disconnected so I pulled the cap, cleaned it (only a tiny bit of dust in there that I could see) and the car runs like new again.

Good luck!

What mileage was your GN when you had your problem with the Cam Sensor?
At 30,000 original miles almost everything is still brand new including the cam sensor.
I'm in the process of replacing the (90,000mi) timing chain, and also replacing the cam sensor since it started to make a ticking noise at start up and then it got quieter when the engine warm up to normal temp. Invest in a ScanMaster as a starting point of troubleshooting.

 

[NorEaster]

My car started idling weird the other day. Cycled thru my scanmaster, saw my blm had jumped up to 140, knew that I had a vacuum issue. Popped my hood and found that I had blow the line off going to the egr. Popped it back together and after the next cruise, blm was down to 128.

Without a scanmaster you might as well just throw money into the car. Even if you think that people with them still cant figure out their problems, they are worth their weight in gold. I would think buying a standalone efi system is just throwing tons of money into a car that might just need a new iac valve.

 

[dennisL]

I agree with the advice to get a scan tool. Without one, you just end up throwing parts at the problem.

Also you say the warm-up idle is crap which is primarily controlled by the chip. I'm not familiar with a ESP chip but if they left the chip's IAC settings stock or changed them without really understanding what each is for, then the warm-up idle will be crap. I know because I spent more than a year programming just the IAC controls. Also the target idle rpm in and out of gear is determined by the chip. Talk to ESP about your idle after you're sure there is no vacuum leak.

 

[3-5.0]

I feel your pain,I can't bring myself to buy these babysitting computers and add ons like Scanmaster power logger translator pro etc.For the sole reason that some guys that have this stuff still can't figure out what's wrong with their cars. I think I am going to bite the bullet and buy a stand alone EFI system and bring the electronics into the 21st-century. My car has many of the same issues and is driving me insane! I don't mean to steal your thread but I guess I have to vent I am very frustrated also. I have waited almost 20 years to own one of these cars. But with all the trouble I've had thus far,it still puts a smile on my face every time I open the garage LOL.

HEAR,HEAR!. lol.

 

[3-5.0]

The only thing a low mileage car does,is the bolts are easier to get to out to fix everything.

 

[broke]

The only thing a low mileage car does,is the bolts are easier to get to out to fix everything.

 

[TurboBuRick]

I feel your pain,I can't bring myself to buy these babysitting computers and add ons like Scanmaster power logger translator pro etc.For the sole reason that some guys that have this stuff still can't figure out what's wrong with their cars. I think I am going to bite the bullet and buy a stand alone EFI system and bring the electronics into the 21st-century. My car has many of the same issues and is driving me insane! I don't mean to steal your thread but I guess I have to vent I am very frustrated also. I have waited almost 20 years to own one of these cars. But with all the trouble I've had thus far,it still puts a smile on my face every time I open the garage LOL.

The problem is that most have no business changing brake pads let alone fixing and making the car run.

Find someone close who knows the cars and can teach you the ropes.

My car is still a stock ECM with a Tpro, scanmater and powerloggger. My car runs better than any other GN I have ever come across. Starts up nice, idles nice, cruises nice, lean cruises nice, makes more power than I could ever need on the street and never skips a beat. You know why? Because I know how it all works.

Educate yourself.

RL

 

[psuog]

thanks, guys! I appreciate the input.

the original cam sensor died the day after my 6 year warranty ran out and that was 19 years ago (about 12k miles). I'll have that checked out right after they run the complete scan and check for vacuum leaks, etc.

after all the work done on it over the last 3 years, I guess just about anything is possible at this point.

maybe it is time I learned a lot more about how this thing runs. I've been reluctant to dive into all the electronics, etc. since I'm much more familiar with carbs, points, etc. than I am with computers, fuel injection and all the sensors. I'd rather rely on people that are much more familiar with the current tech (or old tech as the case may be) and there seems to be a lack of those types of people around here, especially those that are familiar with turbo buicks.

 

[Red C5]

It can be real frustrating chasing problems, been there done that. But unless you have the proper tools to find the problem yourself, you have to rely on others to do it right. I would at least get a scan master.

 

[kidglok]

what chip is in there?

 

[psuog]

I have three chips for it. the stock factory chip, a Kenne-Bell stage 2 chip and an ESP performance chip. the last one is the one currently in the car but the idle problems began before we installed that chip two years ago. I also tried the original chip again but that didn't help either so I'm inclined to believe the chip is not causing the problems.

 

[dennisL]

Well just so you know ...
the warm-up idle in the stock chip is horrible and all the KB chips use the stock IAC settings. As I indicated earlier, I'm not familiar with ESP chips so I don't know if they corrected the problem.

Several years ago, Eric (TurboTweak) and I spent a lot of time getting the IAC settings right and although I don't have one of his latest versions, I'm sure you would be pleased with the warm-up and hot idle with a TT chip over what you're used to.

Oh, and I also was a "adjust the carb, change the jets, adjust the distributor" car guy before I bought my GN. A forum similar to this one was instrumental in educating many of us. Its not too late to learn.

Dennis

 

[JimG]

I have three chips for it. the stock factory chip, a Kenne-Bell stage 2 chip and an ESP performance chip. the last one is the one currently in the car but the idle problems began before we installed that chip two years ago. I also tried the original chip again but that didn't help either so I'm inclined to believe the chip is not causing the problems.

I am no expert here, so no offense if this is an obvious statement, but when changing the chips have you disconnected and reconnected the ecm wire next to the battery and then had a drive to allow the computer to relearn the new parameters?

 

[blackdeathtrap]

yes and x2 on tt chip