94 850 turbo - internmittent engine die at low rpms

Turbolena · Post by **Turbolena** » 30 May 2015, 20:08

Hello,

I have been doing a lot of hunting and have come across other drivers in this forum having similar issues. The car idling at intersection or having low rpms while driving has been peridoically causing the car to power down, much like running out of gas. The car has power and boosts great.
Recently the car has been running a little rougher, and having some smoke out of the tail pipe. Some posts seem to place this on the MAF, but I found an obscure post about the EVAP code 315 which I have that is linked to a purge valve issue, causing a lean mix perhaps .
Here is the sum total of the codes I pulled:

Port A2: 5-2-1 front HO2S preheating
4-1-4 Boost pressure regulator
3-1-5 EVAP System
1-4-3 front knock sensor HO2S signal

(these codes have been around for months, they came back after I did the two O2 sensors, but the car seemed to be smooth and powerful so didn't follow up.)

Newer codes:
A7 1-1-3 Fuel guage open circuit
1-2-2 Outside temp sensor open circuit or shorted to 12v

There has been a complete and well done over haul of pvc and tube system in the past 30k, but it is the original fuel pump. So I am wondering if these codes could indicate a fuel pump going bad?

Your insights are appreciated .

B

Turbolena · Post by **Turbolena** » 30 May 2015, 20:08

It is a turbo wagon.

Post by **abscate** » 31 May 2015, 04:16

Those codes aren't pointing to the fuel pump but the pump and relay are known "high mileage" problems on these cars. Search for threads on jumping the relay for a week to see if that solves the problem or try a junkyard relay swap

Turbolena · Post by **Turbolena** » 13 Jun 2015, 19:08

Thanks everyone. I replaced the purge valve, and fuel pump relay and that seemed to fix the problem, as well as eliminate all the codes including the knock sensor. I appreciate the info.