Saab Link Forums banner

Intermittent check engine light at full throttle

2604 Views 13 Replies 5 Participants Last post by  tuner4life
I am getting a check engine light that comes on for about 2-3 seconds only after going full throttle through 2nd gear, or into third. It never comes on any other time and only stays on for a couple seconds then disappears. It is hard to diagnose the CEL since it goes away so quickly. Has anyone had anything similar to this happen?

The car is a 1992 9kt 100% stock.

Any help is much appreciated
1 - 14 of 14 Posts
Just checked for Codes, Nothing came up... So whatever is going on, it is not storing in the ecu.
I just changed out the plugs, they looked good still, but changed them anyways. The problem is still there. I am going to try a different DI Cassette and see if that makes a different.

The odd thing about this is that the CEL only comes on when in 2nd gear, I can boost hard in any other gear and it doesn't come on, but in second gear it does?!?!?!?

Anyone have any ideas?
Sounds like a fluke.... lol If it's not the plugs or DI - perhaps it's just the ECU being tempermental...
Does it have a tuned ECU?

Not sure what to suggest... sure it's not a TCS light? lol
Nope, the car/ecu is 100% stock. It is definitely the Check engine light, not tcs. (although could tcs be a problem? It has never given me an issue before.)

I just tried it with a different DI and it is still doing the same thing.

It doesn't effect the way the car drives in any way, it is just worriying me.
What octaine are you running? Possible knock maybe - but I do no know why you would not get that in other gears @ the same RPM/Load.

It could just be the TCS freaking out and making the CEL flash on. I'm really just guessing here... lol I have no Idea.
Well, thanks for the ideas.

I always run 92 or better octane in it and it doesn't cut boost like if it was knocking.

Maybe this is just a sign that I should finally delete the tcs, lol
eh - just remove the CEL bulb :)
Maybe you have bad engine mounts and its pulling on a sensor connector. I have seen that happen before.
Maybe you have bad engine mounts and its pulling on a sensor connector. I have seen that happen before.
Actually, you might be on to something here...

when getting on it in 2nd, the shifter till move a bit under load, but not in the other gears. Now I figured it was just something in the trans. I already replaced all the engine mounts (torque mount and 2 lowers) with solid mounts, but the trans mount is still stock....Maybe a poly trans mount will fix it. hmmm...
Well, the problem went away. Could have just been bad gas?
Potentially. When exactly did it stop? Could have been false knock as well, tripping a code but not doing enough to cut boost. Bad gas will knock like hell sometimes, so that's a possibility.
What are you checking codes with, just the CEL *blink blink* with ignition keyed on?

The TCS/ETC computer has a memory to store intermittent faiults, but you need to get them read with a Tech2 with the proper software (and you need the funny little SAAB 10-pin diagnostic connector for it) or an ISAT.

The ETS computer will store (I think) 6 codes even after the battery has been disconnected, that might point you in the right direction.

Otherwise, do the above, try fresh fuel, plugs, maybe try a different DI, and see where you get.

New plugs and different DI were all tried during that tank of gas to no avail. But within 50 miles of refilling the tank the problem went away.

I do want a Tech2 or ISAT.
1 - 14 of 14 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.