Jonno74

iTrader: (9)

Hi all, I've just bought a 1996 GT as my new toy/dog carrier!

see dirty pictures below , picked it up yesterday:








I love it , very tidy, but it has a few niggles for me to sort - (typically, the ebay listing didn't mention the slipping clutch and running issues!)

I'm keen to learn the ropes with the twin turbo control system - I have a code the 66 + associated 22, and a 23 MAF sensor ,

I will hunt for a replacement purple maf to hopefully sort the 23, and then re-evaluate the situation.
In the mean time I will check all the hoses and boost lines, turbo units and all the obvious, however,

could anybody point me to a workshop/technical manual which gives an explanation of the twin turbo system operation?


I have been reading about the solenoid boxes which appear to be a common issue...


any help greatly appreciated.



Cheers,

Jon

midnight

iTrader: (10)

Hi there and welcome to the forum & glad you are pleased with your new toy.Basically your car has 2 turbos,a small one on the L/H/S iirc and a much larger one on the R/H/S.When you accelerate away the small turbo comes into play,and when you reach about 4,500+ rpm the 2nd turbo 'kicks' in.There is a little bit of lag as the 2nd turbo has to spool up,but after that your motoring.If your car has a drivers manual then this will explain the basics ,if not you can source one off ebay for about £10.00.I had a GTB which was a good car in its own right and a proper wolf in sheeps clothing.
Another worthwhile place for you to get some direct more detailed info on your car is here.

http://api.viglink.com/api/click?for...13284434591533

Jonno74

iTrader: (9)

Cheers!

Sprint Chief

Interesting looking car jonno :-)

A quick word of warning about error codes. Sometimes one code causes another to be thrown, so some of those you are reporting may be red herrings. Also, some may be "historical" codes (i.e. codes from the past which have since been fixed).

Note code 22 is the knock sensor. It is common for these to fail on cars of your age. When this fails, the car goes into limp mode as it cannot determine the safe level to run for the fuel you are using. This in turn can trigger other faults. (But then the same is true for other codes as well!)

Code 66 as you note is the infamous generic "twin turbo system fault". It could be almost anything in the twin turbo pipework.

To attempt to eliminate these, I would recommend an ECU learned data reset. This will clear any current or historical codes in your system so you can test to see which code appears first. You should then tackle them in that order. There are a few ways to achieve an ECU reset:

1. Follow the ECU reset procedure (easily found on the internet, involves going through a sequence of steps with connectors etc., and going for a short slow drive).
2. Disconnect the car battery (means alarm off etc. though) for long enough
3. Disconnect the ECU plug with the 12v memory standby connection on it for long enough

I've never used the above methods (I have ways of forcing a reset much quicker and easier than the above!) so I'm not sure how long things need to be disconnected, I've read people say about 2 hours or so.

Once reset, turn the ignition on and check for any codes. Then run the engine, check for codes; take for a short drive off boost, check for codes, then try boosting and check the codes. This way you hope to catch the first code as soon as it happens.

Code 22 if it is a "real" knock sensor fault will be detected very quickly. Code 66 will only be detected once the car is driven on boost. Code 23 could occur any time the engine is running. Since these will illuminate the CEL you should pick them up quickly, pull over and read the code straight away.

Note: code 66 (and code 66 only) can be cleared by switching the ignition off for a few seconds and back on again.

Happy diagnosing!

Jonno74

iTrader: (9)

Thanks for the detailed info, I will try the ecu reset (using the connectors) and take it step-by-step. The CEL has not been on, so the codes may be historical, perhaps of an intermittent nature - however it is running exactly like the maf is knackered or there is a fuel blockage, or both!

Sprint Chief

Surprised the CEL isn't on? All three of those codes should trigger it if they are current! As you say, one (or more) may be historical and then the CEL would not come on.

Code 22 will make the car drive like horribly as well. Without the knock sensor, the car cannot detect det, and drives as if the car has about 80 RON fuel in it. But the ECU reset procedure should help to narrow down the primary cause. (It certainly could be the MAF, but hopefully we can save you some money by homing in on the right sensor first time!)

madfish

Code 66 is likely to be related to the solenoid box, there are refurbished items available with updated solenoids that cure this fault 99% of the time.