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Strange Issues

Guss23

Guss23

Active Member
I just bought a 47,000 mile car out of Virginia. The car was misrepresented to me as it was supposed to be in unmolested near perfect car. After receiving it, I came to find its flaws. The worst is the mechanics of the car. It was very slow starting. It cranked fine but it would takefor five seconds of cranking before it would start. After it started it smelled a little rich but it would go away after a few minutes. It Idled at 1,000 and relatively rough but had a lot more low-end torque than my previous Turbo Trans Am. I change the spark plugs, wires and coil's. I figured it may be bad injectors so I call Eric at turbo tweakand ordered a set of 60 pound injectors and a matching chip. After receiving them we install them as per instructions and now it runs just as rough but the service engine light keeps coming on and the turbo gauge keeps sticking at 10 pounds. As per Eric's suggestion, I bought a scan-master 2.1 that should arrive tomorrow. Is anybody heard of anything like this happening?Any ideas?
 
I would install a fuel pressure gauge and check the fuel pump and fuel pressure regulator. If it is an all original car both those items are likely worn out. The scan master will help diagnose. Obtain the scan master and post all the readings after the car has reached operating temp/160*C.
I am sure lots of guys here can help you figure it out.
 
an " unmolested TTA" is a subjective notion. Depending on what the owner feels is molesting an original car. So, be prepared to find this this was track car that was well maintained or weekend cruiser that was never maintained, and the later is molestation to me.

Just to be a Debbie downer, you may have a wiped lobe, weak valve springs, bad MAF, simple vacuum leak, pre turbo exhaust leak, faulty coolant sensor or IAT or like Jared suggests, a fuel pump issue.

And there is no evidence that the factory dash boost gauge is accurate, you'll need an aftermarket gauge for that.
 
The low end torque is crazy and it does start and run. I got a new idle air and throttle sensor and fuel pressure regulator. I guess I should get a manifold pressure sensor.
 
Even though I suggested a faulty IAT, I've never had one go bad, turbo Buick or TPI and I've never had a MAP sensor go bad in either. I just hate to see anyone throw parts at a problem as it only leads to frustration. I have seen faulty MAFs,coolant temp switches cause problems.

If you are having new issues since the new chip then I'd be suspect of that, I know Eric is the best, and burnt 4 chips for me, one of them had a no-start glitch and needed to go back.

My advice is start with basics and tunnel down till you have found the problem. Fuel pressure is the first thing to check, vacuum leaks and pre-turbo leaks too, those will introduce "false air" into the equation, or air that is unaccounted for post MAF sensor. Your scanmaster will help diagnose lots of stuff too.

On the slow start or "extended cranking", mine did the exact same thing. I tried almost everything, played around with the air gap on the CPS,tried relocating the cam position sensor window, coils, wires, different plugs, more base FP...nothing helped. I have 2 GN buddies and both their cars light off right away, it was very frustrating. I did finally realize that others were like mine and I'd just live with it, and I did.
Till the end of my ownership that is, I found that if I slightly depressed the accelerator on cranking it would light off quickly.
So I came to the conclusion that there was an issue with the calpak chip in my ECM and that it was lean on injector start up fueling, I never resolved the issue and I don't even know if those small calpaks can be re-written but they are basic run or limp home parameters so I figured I'd address it later, well I never got around to it.
 
I have that slow starting issue as well - but only when the car is warmed up and has been running a bit. It will start eventually - it just seems to take a few extra cranks. I have changed plugs, the coil, the ignition module, etc. I also installed a turbotweak and 60 lb. injectors. my fuel pressure is good, the compression is good in all cylinders and the car runs fine. I just learned to live with it as Rich did.
 
OK, just a quick update, We installed the new injectors and chip and the car ran poorly. The idle was all over the place and the check engine light came and stayed on as well as the turbo gage had a tick and would go midrange and stick. I called Eric and he told me that I needed to buy a ScanMaster so I did. We plugged it in and it said O2 sensor failure. We unplugged everything and started the car again and it said coolant sensor failure. we disconnected everything and did it again and it said Idle air control failure. Each time it read something else. My mechanic thought it was possibly a damaged chip from shipping so we installed the original and all of the electrical problems went away but the car was running to rich to drive with the new higher pressure injectors. I decided to sent the chip back to Eric and see if he can diagnose whether or not it is the chip. In the meantime, I did purchase a new O2 sensor, Idle air control, throttle position sensor and fuel pressure regulator to have standing by.
 
8289ta said:
I have that slow starting issue as well - but only when the car is warmed up and has been running a bit. It will start eventually - it just seems to take a few extra cranks. I have changed plugs, the coil, the ignition module, etc. I also installed a turbotweak and 60 lb. injectors. my fuel pressure is good, the compression is good in all cylinders and the car runs fine. I just learned to live with it as Rich did.
Click to expand...
Starter wearing out? Or low voltage to it?
 
Not for me anyway, I did the LT1 starter upgrade,new cables, etc. It's something to do with the ECM and how it gets crank sensor or cam sensor of crank fueling information, I believe.
 
It just takes longer to start. It also idles rough and variable.
I just heard from Eric at turbo tweek. He tested the chip in his car and had no issues. So, the original chip makes the car start slowly and idle poorly with no check engine lights and no there issues and with the new chip still starts slowly and idles worse with the idle bouncing between 900 and 1600 rpm with violent random changes and after a few min the check engine light comes on. With the new chip I also get a tick in the boost gage and it sticks in one position (roughly 9,000 rpm) while driving. When turned off it resets itself. When hooked to the scan tool it gives a variety of sensor failures that are never the same. Wtf is going on
 
Where do you live? You need to put a call out for some help in your area, maybe you live near a member here or on Turbo Buick.

Now, I'm starting to think about the ECM as the culprit so please list the SES codes it threw out. And how it acts when it's first started (cold) and how it acts when it's fully warmed up.
 
Guss23 said:
It just takes longer to start. It also idles rough and variable.
I just heard from Eric at turbo tweek. He tested the chip in his car and had no issues. So, the original chip makes the car start slowly and idle poorly with no check engine lights and no there issues and with the new chip still starts slowly and idles worse with the idle bouncing between 900 and 1600 rpm with violent random changes and after a few min the check engine light comes on. With the new chip I also get a tick in the boost gage and it sticks in one position (roughly 9,000 rpm) while driving. When turned off it resets itself. When hooked to the scan tool it gives a variety of sensor failures that are never the same. Wtf is going on
Click to expand...
 
Its really strange, The low end power that this car has is much, much greater than my previous TTA and is about the same on the high end which is impressive. It breaks loose very easily and, while driving, sounds great. I live in Indianapolis. Unfortionatly, I have not found any GN people around here. Does the TTA share the same ECM as the normal GN? Where do I get a new one??
 
The turbotweak chip goes into closed loop and open loop differently. Could be why it operates differently if there s an issue.?
 
What do you think my next step should be? Find a new ECM? What is the part number for the right one? Anyone know? There is a nos one on eBay right now
 
Try a used ecm first if you can find one on ebay.
When I first installed my turbotweak chip it developed a miss I never had. I thought possibly a blown head gasket because it was running so bad. It turned out to be one of the NGK spark plug screw on tops had loosened and caused a miss. A set of AC plugs and she was running good again. Don't rule out other issues and blow a lot of money on a new ecm.
 
Why would I get the check engine light with the new chip and not the old one? Why would the boost gage act funny with the new chip and not the old one?
 
There are guys here who can help you better then I can. I am still learning as well. Not sure of the part number but it should be on your ecm.
 
The ECM for the TTA and the 86-87 GN's are the same, part # ends in 148.

And somewhat related by generational ECM design (OBD 1), years ago a friend purchased a 30K mile IROC, it was beautiful but had gone through 2 owners since the original and all sold the car because of re occurring drivability and numerous trouble codes. It would throw MAF codes, burn off codes, TPS codes, you name it, it would buck and snort and fall on it's face. never all the same never predictable, the only thing predictable was that it was all "closed loop" related.
I tried everything till an older service tech told me that when one of "those" ECMs would throw random multiple codes it was a bad ECM, till then I never even considered that it was bad so I put a new ECM in with the original calpak and chip and it solved the problem. Here that car traded hands 3 times and countless of hours of work and parts thrown at it for a bad ECM on a car that had under 30K miles and never saw any serious driving.

So yes, it's not a bad idea to have a spare ECM for your car, they're becoming rare so you'll always get your money back.
 
I had one in my 88 iroc and my TTA fail for similar stalling / hard start issues. You can get from any local parts store. CARDONE 777148 and STANDARD MOTOR PRODUCTS EM7148 .
 
So, have you pulled the trouble codes yet? I am leaning toward a faulty MAF as suggested before. We're the plugs fouled up? Lots of carbon.
 
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