1996 850 GLT Random surging/loping at idle and while driv

ERO1 · Post by **ERO1** » 30 Jan 2015, 08:39

One other question on the FPR...if the car is running when you unhook the vacuum line shouldn't it make a difference in how it runs? When I unhook the vac line with the car running it causes no change in how the engine is running...so I think I will order a FPR and see if that will straighten things out.

Think I need to invest in a scanner...

ERO1 · Post by **ERO1** » 30 Jan 2015, 12:19

Just talked to FCP and they said that pulling the vacuum line from the FPR wouldn't really make a difference....so back to square one...

Post by **kahl** » 30 Jan 2015, 13:00

Advance said it was missing on two cylinders. If you have an intermittent ignition problem with two cylinders it would produce the systems you are describing. Plugs, wires, distributor cap or rotor. Have these items evaluated before you go any further.

ERO1 · Post by **ERO1** » 30 Jan 2015, 14:39

How long would it take for these problems to show up....The timing belt was replaced a year and a half ago.....the CEL came on within approx. 150 mi.. It was another few months before I had it checked, but at that time it seemed to be running fine and the Volvo manual said the CEL was an emission issue. Also the light has gone off on occasion for a few hundred miles and the came back on.

Post by **erikv11** » 30 Jan 2015, 15:33

First post says new plugs were installed, and that the old ones were sooty.

It is true that wires, cap and rotor need to be good, and I agree they should be inspected at this time. But they seem unlikely cause any surging as described here. Reads more like fuel or vacuum don't you think? The misfires may be red herrings.

@ERO1 I don't really understand your last question, how long does it take for what to show up? For ignition problems?

I'd get a look at the top of the fuel tank, it is pretty easy to remove the cover over the fuel pump and peer in there. 4 or 5 small nuts.

ERO1 · Post by **ERO1** » 03 Feb 2015, 13:15

Ok..problem solved I hope ! Limped it into town and had it put on a scanner , to the tune of $45.00 !!! ( Think I really need to buy one of those !) Anyway the scanner only showed the missing, which I already knew and the MAF , which since I had it unplugged would show a code.....however the guy at the shop did something to check for cracks in the pressure regulator and said it seemed fine, then he unplugged the MAF and low and behold the car smoothed out and if not perfect ran a whole lot better !!! The only thing that I can figure is that when I unplugged it at home is that the car was cold... so I have ordered a Mass Flow Sensor from FCP and hopefully that will be the end of this..... ! One other thing , since I had replaced the plugs ,I ask him to clear the codes and see if the miss came back, it did not! only the MAF which was unplugged.

Thank -you erikv11 and kahl for responding and for hanging in there with me ! Very much appreciated, for sure!

ERO1 · Post by **ERO1** » 03 Feb 2015, 15:34

eriikv11...sorry, I never saw your last post...my internet is REALLY poor, however , I just want to reiterate how much I appreciate your knowledge and help !

Post by **kcodyjr** » 26 Sep 2016, 19:05

Sooty plugs suggests running rich.

Did you do a fuel filter? Could be close to plugged.

Also, sticking injectors is a possibility at this age.