EDIT 96 volvo 850 turbo flattens on acceleration

Post by **JimBee** » 04 Sep 2017, 16:44

Okay, day 2. I didn't get codes read but test drove and found that it does actually try to kick down, but won't take hard acceleration. With a light foot, gets up to highway speed and cruises there easily enough. The rest below is accurate. Seems like the engine is starving. I'm thinking the fuel pump might be failing.

When I'm rolling and hit the accelerator the revs just flatten out. Engine doesn't stall, though does seem to shudder slightly when I ease up the accelerator, then resumes as normal. All upshifting from startup seems correct, smooth, but positive. The dreaded arrow isn't lit.

Post by **tryingbe** » 04 Sep 2017, 17:57

There is a connector at the throttle cable at the firewall, make sure it is secure and plugged in.

Post by **rspi** » 06 Sep 2017, 13:25

When mine was doing that the fuel pump failed in about 2200 miles. No issues after I replaced the fuel pump.

Post by **bmdubya1198** » 06 Sep 2017, 18:45

Yeah, this sounds more fuel or sensor related than transmission related. Lucky you!
Fuel pump doesn't sound unlikely. It almost sounds like the throttle position sensor could possibly be an issue.

Post by **JimBee** » 07 Sep 2017, 12:10

I have a Walbro fuel pump cartridge and a complete failed pump that I need to assemble. I'll put that in. Even if that doesn't fix it, the installed pump is pretty old so that will be a good update anyway. If that is the problem, it's nice that it's still driveable but with notice that it's heading south.

Today, I'm getting it on a lift to check out the infamous suspension knocking sound and while I'm there I'll ask the tech to put a fuel pressure gauge on the rail. I guess fuel pressure should be about 43 psi.