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Discussion Starter #1
Hi everybody

I am having this wierd problem that has happened twice already. I went for a long drive and came back home. 20 minutes later I go out and start her up to go to class. The whole car shakes and feels like it is running on 3 cylinders or something. In fact, it probably is since I felt the exhaust pulses coming out the tail pipe and it was really uneven. I was wondering what could be causing this? It runs fine otherwise but this problem has come up once before. After I rev the engine hard it will clear itself out and return to normal? :confused: Any input on this? I would really appreciate any help!!

Lawrence

ps
Its a 97 900se turbo
 

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I hate to say it but the first thing that comes to mind is a failing DI (direct ignition cassette). If you have done no ther maintenence that is. A cracked or otherwise bad sparkplug COULD be the culprit. So, check that first. But, when my car got to the 3 cyl mode, the DI had just a day or 2 left...
 

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Discussion Starter #3
Thanks for the reply bkrell!
Just to clarify things, do you think it is still the DI if the shaking/running on 3 cylinders things goes away when i rev the engine hard? If i floor it when it starts doing this it will go away. How wierd huh? Just making sure it isn't a fuel related thing or something. thanks again for the reply!

Lawrence
 

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Yeah, it still could be. The two times I've run on 3 cyls (in this car) are running together, but I would wager one of the two choices. Of course, there's always the odd sensor that goes out, but it should throw a CEL...


Have you gotten any CEL's yet?
 

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This is exactly what happened to mine.
it'll do this for a while, and then you won't be able to "fix" it by revving.

Mine took something like 10k miles from the first time it happened to complete failure.

Start Saving your [email protected] $325.. it's one of the more expensive one-piece things you'll ever have to buy.
 

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Before you get confident that your DI can last thousands more miles...


As seen in my post, the death of a DI doesn't seem to follow any set pattern. For some people, the process is slow and drawn out. For others, they crank the car and...nothing. As I mentioned, mine went from slight hesitation, to 3 cylinders, to dead on the side of the road in about 48 hrs.

There is also the danger, as I can again relate from personal experience, that you will ruin your catalytic converter and have to pay for a new one of those as well as a DI. I was confident I could make it to work on my daily commute and ended up rolling to the side of the road and burning catalyst shot out the tail pipe. When I had it replaced, the cat's internals were a melted mass. When your car is misfiring due to a lack of spark, that doesn't mean that your injectors stop spraying fuel. This extra fuel ends up collecting in the cat and can catch fire.

Upside-I got a Magnaflo high-flo cat!

Downside-In addition to $300 for the DI, I paid $100 for the new cat and its installation plus $200 to get my car towed 30 miles back home...:cry:

So...just keep in mind that DI cassettes have a way of being unpredictable.


Now, as I mentioned earlier, the fault could also be a spark plug. On a seperate occassion, a wayward radiator hose shot coolant all over my calve cover, sending some under the DI and cracking a plug. This caused the same problem. I had a spare DI which didn't improve the situation, this led me to all sorts tinkering before I realized the coolant had cracked the plug, shorting it.

Either way, a misfire that severe should be causing a P0301, 2, 3, or 4 code. That is the OBDII code for a specific cylinder misfire, with the 1-4 indicating which cylinder.
 

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Discussion Starter #7
Thanks for all the replies guys. I will definitely buy a new DI cartridge soon. Do you guys know who sells them for cheap online? Interestingly enough, I never get CEL's when this happens. Probably the spark plug didn't stop firing completely so the car didn't register it as a misfire. Who knows?
 

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it's a toss-up between eeuroparts And Ebay.

they're both about the same price....
 
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