97 850 T5 - Stalling, hard starting MVSOLVED dist rotor bolt Topic is solved

[keithf]

Hey Volvo friends - sorry for the long description, I'm trying to provide as much context as possible.

For the first time in 16 years, my 97 850 T-5 died while driving. I had just hit the gas hard when, after maybe two seconds of acceleration, it sputtered then stalled. I made it onto the shoulder and tried to start the car. After a few cranks, it started. I then proceeded to accelerate, but it then stalled out again. This pattern repeated a couple times when I realized that it wouldn't stay running above (approximately) 2000 rpms. Luckily, I was only 2 miles from home so I limped home at 10mph. At low rpms, it seemed to run fine and didn't stall.

Background: A few months ago, it had started 'missing' when accelerating and, in a short period of time, I got a CEL (misfire cylinder 4). So, I replaced the plugs, distributor cap, and rotor. I also took the time to replace the PCV kit, as it was old and the hoses were brittle (it wasn't clogged up though). That was about 1,500 miles ago and it cured my acceleration problem. The engine was running like new.

About 2 weeks ago, I got a CEL and the engine started running rough. I was close to an auto parts store and they read the code - misfire on cylinder 1. That night I ordered new spark plug wires from FCP, figuring that was the only thing I didn't replace a few months back. I got the new wires, and installed them. It was running well, however, I noticed at WOT, I was feeling some hesitation.

Between the time of the new wires, and my current issue, I drove the car over 100 highway miles, with an average of 30.2 mpg fuel economy (it was all hwy miles at 65mph). I had filled up the fuel about 5 miles before the incident, and took it through a car wash. There are 193K miles on the car.

At present, the car is hard to start. When it does start, it'll stay running at idle. When the accelerator is pressed, it stalls at higher RPMs.

Troubleshooting:
- I have spark. Pulled out #1 and #2 plugs, placed against metal, and cranked engine.
- I have pressure in the fuel line. I don't have a fuel pressure gauge, but the schrader valve spits out fuel when pressed.
- I can hear the fuel pump spinning from the tank when the car is turned on.
- Although I seemingly have fuel pressure, I jumped the fuel pump relay. No change.
- I don't see any vacuum hoses or electrical connectors broken or disconnected.
- CEL is on but I don't know if there are any new codes. I didn't reset it between the time of the wires replacement, and the current issue. I usually rely on the auto parts store, but I finally ordered a ODB-II reader on Amazon, seeing that I can't get the car out of my driveway.
- I cleaned the AIC, which seemed to get the car to start a little easier (but not entirely sure).

My plan tonight is to check out the fuel pump regulator, and replace the fuel filter.

Any other ideas?

[phils94850]

Keith... welcome to the site. . Since the car will start but difficult to accelerate I would check to make sure you didn't bust a rubber intake hose, also.. its common for these cars for the cam position sensor or crank sensor to go out but usually you wouldn't get a spark with the cam sensor.

[deepsouth]

When the cam sensor on my V90 went out the car would try to stall above 2000 rpms. It did, however, throw a cam code.

[RussB]

That's incredibly good fuel mileage! 12+ years in my '96 T-5 have never seen more that 28mpg, and only a few times at that


That said, look for torn turbo piping. The misfire codes would make me want to take compression readings for peace of mind. I also wonder if there's a clogged fuel injector? Or perhaps the car is starving for fuel?

[keithf]

Thanks for the replies, guys. I've checked the intake hoses and turbo piping - all looks good. I also changed out the fuel filter this eve, but the problem persists. (The idea of it starving for fuel is why I was thinking clogged fuel filter.)

My Actron code scanner should show up tomorrow eve, so hopefully that will give me some answers. I'll post back what I find.

[phat78ta]

Did you top off the tank when you filled up? Could be you got too much gas in the tank and it flooded into the vapor recovery system. Under load it may be sucking too much fuel in from there and flooding out. Someone smarter than me may have a link to the topic. I've seen it covered on here many times.
Edit:
Do you know the ethanol content of the fuel you filled up with? My wife's n/a 850 ran like crap with gas that has high (10%) ethanol. Had to use refuel treatment and octane booster to make it run decent.

[keithf]

hmmm... I did top off, which is my usual routine, and I always go to a name-brand gas station. The only thing different was that I put 93 octane fuel in, whereas I usually run 87. I can't imagine that would have caused a problem (it should have helped it run better).

Here in central Texas, 10% ethanol is posted on every gas pump.

But, the idea of bad gas....maybe.

[mecheng]

Check your fuel pressure regulator

[E Showell]

A standard diagnostic in these situations is to unplug the MAF sensor and see if that makes any difference to engine running. If it runs better with the MAF unplugged, you may well have a failed MAF.

[850_olaf_nz]

when I had these symptoms, it was the MAF. I hadn't yet replaced the leads and plugs, though.
HTH

I have since replaced CTS, Cam Position Sensor, and other stuff as general maintenance.