Car stopps accelerating -SUDDENLY!
#1
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Hello, Just bought a 87 944 turbo, 117000 miles. Stock except for a boost regulator I put in to bypass a failed cycling valve. Worked fine for 2 weeks. but Now the car stumbles and falls completely flat periodically while under hard acceleration. Boost guage(stock) reading about 1.8 bar. Have I got the boost too high and the DME cutting spark or fuel off? Anyones comments greatly appreciated!
Andrew
Andrew
#4
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Maby. I'll check, but when the car decides to stop accelerating it does so comlpetely. There isnt even any na type of push happening. It really does stop. Feels like somebody stomped on the brakes and forgot to tell me. Wouldn't the car keep accelerating but do so at a much slower rate if it was a BOV failure? I dont know? I live on northern Vancouver Island and have to quickly pass logging trucks on a twisty highway. This alone is often hair raising but now with unpredictable acceleration a bit more than just hair is rising!
#5
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Yeah! Thanks ROCK, it must be a overboost protector. It's only happening in 3-5th now that you mention it. Anyway to turn theoverboost protector off? Engine is old and will be rebuilt soon anyway.
#7
Lazer Beam Shooter
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Yeah. Ive been there done that. Unfortuneatly for you (but fortuneatly for your engine) the boost cut cant be turned off unless you change the chipset.
I burnt a valve overboosting it was no fun.
Id just see if you cant open the boost controller a turn. It may just be overboosting by a bit and 1PSI may fix it. Keep in mind the stock turbo is basically useless after 15psi anyway. Intake temps skyrocket and power gain is minimal at best after 15psi.
The reason its only happening in 3rd-5th is thats when the turbo can stay spooling for longer periods. 1st is too short to really get full boost and 2nd if it does get full boost its usually only for a second.
I burnt a valve overboosting it was no fun.
Id just see if you cant open the boost controller a turn. It may just be overboosting by a bit and 1PSI may fix it. Keep in mind the stock turbo is basically useless after 15psi anyway. Intake temps skyrocket and power gain is minimal at best after 15psi.
The reason its only happening in 3rd-5th is thats when the turbo can stay spooling for longer periods. 1st is too short to really get full boost and 2nd if it does get full boost its usually only for a second.
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#10
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1.8 bar on the stock guage, so that would be .8 bar absoulte, or about 11 to 13 psi thereabouts. But I'm aware that the stock guages are notoriously innaccurate. like my spelling.
#11
Nordschleife Master
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I think I'm having a similar problem but I know I'm not hitting over boost protection as I've got custom chips.
It does it randomly and can get really annoying. I mean I can push the pedal to the floor and it doesn't do anything then a few seconds later it just kicks in. I have a feeling its spark related. I a jacobs coil and the wires and plugs are two years old. My cars been running pretty rich so they're probably bad.
https://rennlist.com/forums/944-turbo-and-turbo-s-forum/382738-what-are-the-signs-of-a-clutch-on-its-way-out.html
It does it randomly and can get really annoying. I mean I can push the pedal to the floor and it doesn't do anything then a few seconds later it just kicks in. I have a feeling its spark related. I a jacobs coil and the wires and plugs are two years old. My cars been running pretty rich so they're probably bad.
https://rennlist.com/forums/944-turbo-and-turbo-s-forum/382738-what-are-the-signs-of-a-clutch-on-its-way-out.html
Last edited by Keithr726; 10-26-2007 at 03:17 AM.
#14
Lazer Beam Shooter
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You do realize that if you hit it once, it will cut the boost soon thereafter.
So if you hit it once at like 15 PSI, it will cut out at like 6-7 PSI next time.
It takes time to reset or the car needs to be turned off and on
So if you hit it once at like 15 PSI, it will cut out at like 6-7 PSI next time.
It takes time to reset or the car needs to be turned off and on