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Discussion Starter · #1 ·
My 850 turbo started cutting out and going again a few weeks ago and it's beginning to get worse. It started under heavy load at higher rpm, and under load going over bumps. Now, it's under load at almost any rpm and frequently over bumps. The Check Engine light comes on the moment the engine cuts and goes away immediately on restart.

I had a throttle position sensor code-- I replaced the sensor and cleared the code, and it hasn't come back since.

I replaced the fuel filter. The fuel pressure is fine.

Haven't looked into the coil yet but I plan to.

I'm beginning to think, mostly because of the weirdness of it happening over bumps, that there is a loose ground somewhere, or there's an electrical connection issue/loose relay or something like that.

Anyone have any ideas?
 

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there are probably 5 or more grounds on the engine taking them off at each end and hitting them with a wire wheel will help ensure good connections
also checking your connections at the battery and starter and power supply to the fuse box are also good thing to look over to ensure its not the source of your issues
 

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Whats your fuel pressure at?
 

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Discussion Starter · #4 ·
there are probably 5 or more grounds on the engine taking them off at each end and hitting them with a wire wheel will help ensure good connections
also checking your connections at the battery and starter and power supply to the fuse box are also good thing to look over to ensure its not the source of your issues
Thanks, I got pulled away from this car for a bit. I am pretty sure you're right about the connection issue. I hope to tear into it here shortly.
 

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Discussion Starter · #5 ·
Whats your fuel pressure at?
I believe it was 36psi... don't remember now. it stayed pressurized for quite a while after turning off. I looked up several threads and the psi and longevity after shutting off were consistent with what people said was normal.
 

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Is the check engine light coming on still after you replaced the TPS ? If so you need to check codes. Ignition coil would be highly unlikely. Impossible to diagnose with such little info but I'm leaning towards a mass air flow sensor, Or secondary ignition, Plugs wires, Dist. cap, And rotor.Loose grounds, Connections, Or an odd wiring problem is possible but unlikely unless someone has been working on the car and caused it.
 
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