My 93 940 Turbo all of sudden can't get out of it's own way. It's usually very responsive and there was no event leading up to this. Just noticed it when I was accelerating on to the interstate yesterday. No problem around town. TD

 

when my 1992 turbo did that, it was the big silicone rubber pipe that goes from the MAF/AMM into the turbo. the turbo end of it was oil soaked and all squishy soft, and under heavy acceleration and upper mid RPMs, it was sucking out from the clamp, and letting air in that was bypassing the MAF... cure was a new silicone intake hose, and clamp.

but there's lots of possible reasons.

 

Thanks Pierce. Good to hear from the Guru! I wish my problem was that simple. Everything's solid at all intake connections. I replaced that hose in 2015 before my cross country "trip of horrors" which you might remember. I installed an aftermarket MAF/AMM at the end of that journey and it solved my flame out incidents. I have had some recent almost-stalling-when-idling & some fast-idle scenarios lately so I'm suspecting that MAF/AMM. Could it be the culprit in this lack of power issue? TD

 

does the turbo boost gauge do anything funny when the power sags ? what about the tachometer ?

 

Pedal to the metal, tach maxes out at 3500 rpm & boost gauge only moves about 3/8" into the boost zone of the guage. Put in a new turbo aprox 4 yrs ago.

 

the boost gauge should move to about 50% of the way from 0 to max

well, assuming its not something mechanical, its either not getting enough air, enough fuel, or enough spark. hard to say which. no error codes on the ECU (pin 2) or ICU (pin 6) ?

 

Read three codes:

311 is no surprise as the speedometer has been intermittent for years but has never affected power but it could explain the idle anomalies.

231 could also help explain the idle although never had any idle fluctuation before installing new AMM/MAF

322 seems like the most likely clue to follow. AMM Term. #4 is obvious and easy to check, what is meant by FI #8?

 

I believe they mean pin 8 of the fuel injection computer, more commonly called the ECU. This is located in the passenger footwell, on the outside wall, just forward of the lower door hinge.

 

Nothing visible regarding wire connections. I still have the old AMM/MAF which only malfunctioned in very hot weather which I concluded, in conjunction with it's close proximity to the turbo, was causing a heat related open circuit to occur. I'll re-install it and see if I get a return to normal power. Having spare CIS & EFI system sensors etc was how I did most of my diagnosis in my shop years ago. Why should "newer" system diagnosis be any different? TD