'95 850 t5-r Running Rich and Stumbling after short drive Topic is solved

warmblood58 · Post by **warmblood58** » 08 Mar 2016, 23:35

Finally got the new to me 850 T5-r running and decided to take it on a drive so I could evaluate and change oil. It idled for about 10 minutes and as this car sat for six month, I moved the auto trans selector through different settings slowly and noted good lockup. I drove off slowly and car felt smooth with no hesitation. My confidence was up so I took it up and over a hill and after clearing the top and driving at about 55, I heard a backfire and then engine started to stumble. I was able to limp home with car surging and stumbling and occaissionally dying at stop lights. Tank was about 1/3 full and as this car had sat so long with bad gas, I had previously drained tank and cleaned out pump basin and installed a working pump and added a bottle of Techron Complete fuel treatment and some Startron enzymatic cleaner. My first thought was perhaps the fuel treatment which had sat in tank for the past 2 weeks had freed up a bunch of crud and had fouled the new fuel filter. I stopped at a gas station and filled tank to full. Prior to driving car, I did the following -

Installed autolight copper plugs and gapped to .28 (autolite was all local Flaps had in copper)
Rotor and cap had some serious carbon tracking so I cleaned them up knowing I would buy a new cap and rotor after I had car running
Cleaned intake (very dirty) with intake cleaner
Cleaned MAF with MAF cleaner
changed vacuum lines to turbo (the old lines were completely degraded and crumbling)
Plug wires were new according to previous owner and they appeared new
Top end was done at about 180,000 by a volvo dealership - car now has 209,000

Any ideas? The backfire seemed to trigger the stumbling/surging as prior to this, the car was running quite smoothly and pulled strongly up the hill which is quite a grade. Thanks!

Post by **tryingbe** » 09 Mar 2016, 06:40

6 month old gas or fresh gas?

FastYellow · Post by **FastYellow** » 09 Mar 2016, 08:04

I would flush out the fuel tank completely. Any codes show up?

Post by **erikv11** » 09 Mar 2016, 08:18

Codes, agreed.

I would check all of the rubber, especially the intercooler hoses. And test the MAF, it's free (unplug it, then start the car).

Post by **Ozark Lee** » 09 Mar 2016, 08:41

What brand are the new ignition wires? I tried to run a set of Advance Auto Parts house brand wires and the car behaved much as you described until I bought a new set of Bougicord wires. Even Bosch wires gave me trouble.

Like others have said, codes are your friend be they OBD-1 from the button boxes or OBD-II. On a '95 you should have both OBD-I and OBD-II. If you pull the OBD-I codes be sure to post them back with the port letter and number included. For the OBD-II codes be sure to post the actual Pxxxx number. Many scanners try to give a diagnosis for the code but more often than not it is an incorrect diagnosis. The actual code number is much more meaningful.

...Lee

warmblood58 · Post by **warmblood58** » 09 Mar 2016, 10:41

Thanks, yes, tank was drained completely, new gas added along with fuel treatment and fresh fuel was pushed through fuel line before reattaching to fuel rail. The pump basin was full of this red brown ooze (modern gas = junk) which I cleaned out. Have not checked codes yet, will do so if it does not rain hard today (no covered garage). I think I might have heard a pop before backfire last night which might mean I blew off a vac line somewhere - either way I will check all vac and intercooler connections. I have been reading a lot about the o2 sensors (the first sensor) going out and causing these run rich problems . . . . learning about this car fast! Today, I am picking up a small part at the volvo dealership that did the top end work and am going to see if I can get a full report of past work by submitting vin so I can see what was done in the past. The emission system seemed fine (I would think they would have done this work when head was pulled at 180,000) as I pulled oil filler cap and had some suction vs positive air (using glove) Thanks all!

warmblood58 · Post by **warmblood58** » 09 Mar 2016, 10:43

I believe they are bougicard, I will double check - so these wires could be fine for 20 minutes or so and then cut out and create a rich condition?

warmblood58 · Post by **warmblood58** » 09 Mar 2016, 16:48

Always nice when it is a easy problem, in this case, a lower intercooler hose was not tightened and blew off . . . I doubled checked everything else and drove car, power back but I can tell plugs are junked up a little and need a good long hot freeway drive at 70mph +

Thanks all

FastYellow · Post by **FastYellow** » 09 Mar 2016, 16:55

Glad it was an easy fix!! Drive her like you stole it!
I also just stumbled upon a vaccum line that was causing gnarly fumes and continuing smoke out my t5R tailpipe plugged it in. Smoke gone!!

warmblood58 · Post by **warmblood58** » 09 Mar 2016, 18:18

Nice! I was surprised how soft and crumbly the vac lines were on the turbo side given that a dealership at done the top end 29,000 miles ago- boost must have been week. Gave it an oil change this am ( 10/30 Mobil 1) and now 20 miles from home. Going to hit the freeway shortly, flushed brake system yesterday (fluid was actually super clean) Tomorrow, flush coolant system, add Zerex G5 and Subaru coolant additive( good stuff!)