my car is a 1996 volvo 850 Turbo
When i bought this car it was from the first owner, and everything that was on the car was done by a volvo dealership since 1997, never taken anywhere else.

when i first had this car it ran great, but as i've put parts on i've been getting more trouble!!
Engine Modifications:
IPD CHIP
MSD ignition
IPD 8.5 mm wires
Eurosporttuning cold air intake
VDO boost gauge(holds 10 psi, over misfires)
Re-done all Boost solenoid vac wires
bosch +2 spark plugs
volvo fuel pump, + filter as of 3 months ago
cap and distributor(done with new wires and MSD ignition*)
I run MOBIL 10w 30 synthetic

I installed the europsport intake first then re-did vacuum lines.

Then when i put on the new IPD chip(117k) i got a misfire, real bad in the top end, solution: new wires, cap, rotor.
I also asked my mechanic to change the length of the turbo on the top to hold longer(dont know if this has anything to do with this) It also smells rich ever since i got the chip, especially now.
I had installed the platnum +2 plugs when i put on volvo cap and rotor and msd ignition which i had to take the end off and install new crimp for MSD ignition myself and also instal the IPD wires at the same time.
My misfire did not go away, it just is less of a misfire. So maybe it was the plugs, so i put in the volvo plugs for a week or so. Compared to the bosch plugs it runs rougher and misfire is worse.I have even switched volvo plugs to cylinder 1 and 3 barely a difference. The misfire code is p0301 and p0303 and multiple misfire code. This is ONLY on those two cylinders. also this misfire is only from the range of 4200 to 5700.
Then i bought the VDO gauge, and when i take off it will hold 10psi then about 12, when it gets to 12psi its around 4 thousand RPM and anywhere past is misfires. If i hold the petal down the misfire will go and come, then usually it spikes to just under 15psi (14.7 ipd spec) and the next gear and up it will hold 10/11 psi almost never over still misfiring around the same RPM. it also burns a little more oil.
I have also went back and used electronic cleaner on the cap and rotor to make sure everything is as clean as could be!

Do you this i should re-install the bosch coil?? Do you think it is a leak from somewhere? do you think i should get colder plugs?? Should i try re-installing original turbo box? Do you think it could be the wires and try to return them??
I dont think its the MAF because i get no code from that, though i havent cleaned that yet....I do not want to pay a mechanic to fix this problem for lots of money when i could do it myself. I am waiting to get a air/fuel gauge and oil psi gauge to help in this problem. The car runs perfect otherwise, perfect. What could it be?? This is my dream car and the ONLY problem is this misfire!!!! Should i get colder copper plugs?? Bosch/ngk/other?? Ive gone through alot of different peoples forums and i dont find my exact problem follow with every one elses.....bummer huh!

Peter

 

I always use the bosch platinum single electrode plugs.
With the exception of the MSD and IPD wires I pretty much have the same setup and am running 12 PSI all day long with no problems.
I have heard these cars don't really like the MSD. I have never tried to run one or even a highoutput coil. Was thinking on maybe giving it a try but haven't gotten around to doing it yet.

What brand was the cap and rotor?

I use Bosch cap and rotor and bougicord(wires)

 

I used volvo cap and rotor. IPD wires. Decided to go 8.5mm since i was putting in the chip.
Should i go back to the original coil?? this is my next step! should i go bosch copper plus??

 

I would try the OEM coil and see if it makes a difference. You still have the original one?
I haven't used the Copper plus yet so unsure.
I have the platinum and have them gapped at .025 thousands.

 

Sounds to me like a spark plug/coil issue. Try the easy stuff first.Could be a bad ECU chip flash (very rare) but I'm betting plugs

 

Were you able to fix your problem? it is very similar to mine and I'm wondering what helped. I only replaced the distributer and button and the spark plugs with iridium core autolites, the coil and wires are original. I get a missfire on cylinder 5 only but it feels really bad when i press the gas peddle any more then half way down. if I don't try to accelerate any more then moderatly, I'm usually fine.

Thanks in advance.


Daniel
1996 850 turbo wagon with 120k

 

What are the plugs gapped at?