1998 S70 T5 Miss on WOT-MVSOLVED w/VOLVO OEM Plugs

Post by **MoVolvos** » 11 Mar 2014, 01:21

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Inter-cooler hose or potentially Throttle Body hose collapse.
http://volvospeed.com/vs_forum/topic/13 ... is-opened/

http://volvoforums.com/forum/volvo-850- ... deo-61090/

Blessings,

BKM
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Someguy3331 · Post by **Someguy3331** » 10 Apr 2014, 12:09

Turns out it was low fuel pressure, replaced the pump and currently waiting for a fuel pressure regulator that was on back order, and it should be good to go hopefully.

Someguy3331 · Post by **Someguy3331** » 13 Apr 2014, 13:03

Honestly I have run out of ideas completely now, the fuel pressure was low at about 30-35psi. So I changed the fuel pump, the fuel pressure regulator, threw on a new fuel filter and absolutely no change. The car is running extremely rich according to the AFR gauge and it still cuts out and starts to randomly misfire once you make 10psi of boost. I also replaced the spark plugs, wires, cap and rotor. Although that's not going to affect fuel pressure. Compression also tested out at about 170psi on all cylinders. I think the only thing in the fuel system left to replace is the pulse damper, could that cause low fuel pressure? if not, does any one have any ideas? Also the intercooler hoses and throttle body hoses are not collapsing, I have the ipd reverse intercooler piping kit.

SpeedyPete · Post by **SpeedyPete** » 13 Apr 2014, 14:23

What Brand of cap, rotor, wires and plugs did you replace with? Cap and Rotor should be Bosch, Wires OEM Bougie's, Plugs OEM Volvo, 2nd choice NGK or Bosch Copper core gaped at .028. Your best bet is to stay OEM with these. My 98 T5 had a misfire here and there until I went back to all OEM parts. I to thought I had a fuel problem but it turns out it was the after market tune up parts. My car (daughters now) is stock, has 180K on it, runs strong and burns no oil. Running Rich? Check your O2 sensors and CAT. You should be pulling some sort of codes out of the ECU. Your ARD Tune may be playing into this: give them a call. Stay calm and good luck with this. Regards, SpeedyPete

Post by **rspi** » 13 Apr 2014, 15:35

Nothing to do with your misfires but you really should run full synthetic. Better protection for hot turbos.

Check with ARD. Some people play with spark plug gap to cure misfires.

What color injectors are you running? I know some people change injectors with ECU mods.

Yes do check your intake manifold bolts. An intake leak can cause misfires when stresses but usually cause rough running all the time.

How did you get your compression numbers up? Did you do a wet and dry test?

Someguy3331 · Post by **Someguy3331** » 14 Apr 2014, 00:05

Using Bosch cap, rotor and plugs. I am using the ipd blue spark plug wire kit and the MSD ignition coil. I will check the spark plugs and re gap them just to be sure. I'm not getting any error codes when I drive it normal. Only when I get to around 10psi of boost or more it misfires and I just get codes for the misfire. I have an Air/Fuel ratio gauge in the car and that's where I am reading that its running very rich until you let off the gas and just coast or downshift then it will almost go to normal. As far as the cat goes, I have the full turboback ipd stainless exhaust that is only about 3 years old. I am still getting low fuel pressure though, it's around 35psi still (From what I looked up its supposed to be around 40 but I'm not sure I only found one answer). I may get in touch with ARD and see if there has been any issues with the tunes, although the car has had the ARD tune for over 2 years now and I've only recently had this issue

Someguy3331 · Post by **Someguy3331** » 14 Apr 2014, 00:09

rspi wrote:Nothing to do with your misfires but you really should run full synthetic. Better protection for hot turbos.

Check with ARD. Some people play with spark plug gap to cure misfires.

What color injectors are you running? I know some people change injectors with ECU mods.

Yes do check your intake manifold bolts. An intake leak can cause misfires when stresses but usually cause rough running all the time.

How did you get your compression numbers up? Did you do a wet and dry test?

I've been using the Synthetic blend because that's just what the PO told me he always used, and I believe the injectors are yellow but I will have to double check. As for the intake bolts I recently did a flame trap kit on the car and the issue came up shortly after so that might be a possibility. I'll have to make sure they are all snugged up. Forgot to add that it was a dry compression test

Someguy3331 · Post by **Someguy3331** » 19 May 2014, 08:52

It has finally been resolved, I ordered a set of volvo OE plugs and its been fine ever since. On the bosch plugs I was using the gap had kept getting changed on them somehow and that seems to have been my issue.

Post by **matthew1** » 19 May 2014, 09:32

Thanks for the followup, Someguy.

Post by **abscate** » 20 May 2014, 10:36

Someguy3331 wrote:It has finally been resolved, I ordered a set of volvo OE plugs and its been fine ever since. On the bosch plugs I was using the gap had kept getting changed on them somehow and that seems to have been my issue.

Postby ChiNorm » 09 Mar 2014, 15:23

These motors are real sensitive to spark plugs. My IM once tore out his hair for over a day trying to cure a miss on my car, then put in a set of VOLVO OEM plugs.

The miss departed imediately.

Weird, but true.

Good luck.
ChiNorm
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Posts: 211
Joined: 06 Nov 2008, 11:40

ChiNorm - you are indeed Samurai......

1998 S70 T5 Miss on WOT-MVSOLVED w/VOLVO OEM Plugs

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