HI!

im having the exact same issue as Benihana had in this post: https://volvoforums.com/forum/archiv...p/t-24296.html

I have also monkeyed with the wastegate rod, although it seemed fine after i did it (a few years ago). I have replaced just about all sensors I can find, the exhaust system, ECU and remapped ECU, vac leaks, plugs wires, coil 02 sensors, injectors flow tested and cleaned etc, pretty much everything he did all to no avail, i even tried higher flow injectors, that gave me a too lean CEL, factory injectors went back in and no light.

the car is running very rich, i have a wideband O2 sensor and gauge installed and it sits at 10 to 11.5 most of the time, even at idle and it will start to smoke after sitting at idle for about 5 to 10 min.

but on occasion it runs perfectly, the a/f gauge reads 13 to 15 at idle and the acceleration is smooth and boost is quick, then I will stop at a store and when I restart it, back to broke it goes. it seems to run correctly more often when its cold (3 days out of 10 instead of 1 when its hot), and the intermittentness of this issue makes me think its a bad sensor or vacuum leak but all attempts to find these have come up short. Is there a AIT sensor I am not seeing? The coolant sensor went bad on me once and it would barely run, like to the point I smell lots of gas and lots of black smoke was billowing out of the tail pipe when it would start.

when its 'broke', it accelerates rough like its missing and throttle response is slugish, shifts are different, then at about 3500 is clears up, that is consistent.

It was getting O2 slow response with a Bosch sensor, I replaced it with a factory one and the CEL has not come on again but its defiantly running rich.

I am going to try to reset the wastergate rod this weekend, but what struck me is that i was looking for another T-5 or R that was running right to put all my stuff on and I ran across 2 ads where the owner said the car was only boosting to 6psi and it seemed slugish like Benihana's post. Is this an undocumented common problem? Any one else come across this and find a solution?

thank you!

 

My car was throwing a too rich code. I did a couple of things at once that seemed to fix it.

Put ipd plug wires on it.
NGK plugs
MSD ignition from ipd
Also readjusted my wastegate rod back to stock. My friend and i were looking at the add on ipd about wastegate adjustment to try and get a little more out of it and i think he turned it to much. So i set it back a couple of turns to make it longer.
I can't say which one made it stop throwing the code cause i did all these things at once, but no more running rich codes and car runs great.

1995 850 t5r

 

Mass Flow sensor old?
What are the plugs gapped to?
fuel pressure good?
Did the waste gate shaft ride up?

 

What should the plugs be gapped to on our cars?
What do you think is the best plug for the car? Part #?
I have recently been doing alot of driving want to keep it running good.

1995 t5r

Thought i meesed up the front tonight a huge racoon walked in front of us

 

OK so i found a big vac leak, the elbow on the intake leading to the valve for the flame trap system was completely destroyed. I fixed this issue and its running MUCH better, however now its running really rich at startup and sometimes when just cruising. my AEM A/F gauge (separate o2 sensor) reads as follows:

start up cold, 14 .5 to 15.5

once it has ran for about 30 seconds it drops to 10 or less (unreadable on gauge) and you can smell fuel and lots of black smoke when you punch it.

then after about 3-5 min of driving is comes back to 11.5 to 13 for a while then it will drop to 10 or less again

then there will be what feels like a big miss and the gauge will come back up to 11.5 - 13 range.

then it will slowly drop again to 10 and this cycle repeats.

my gas mileage has gone in the crapper.

I have yet to adjust the wastegate rod back and will do so tonight.

Im gonna check the fuel pressure regulator as well, maybe its leaking???

MAF, o2, coolant temp and tps are new (with in 6 months)

i just put new plugs in (with new cap and rotor), but I didn't check the gap, shame on me. What should it be, what Hayne's says or is there a better gap?

wires are IPD with a nology profire coil

 

I checked the fuel pressure regulator and it was not leaking, I also readjusted the wastegate rod, all to no avail. i need to check the fuel pressure next.

I created a vacuum leak at the tree that the idle air valve connects to. the A/F ratio will still drops to 10 after start up but after a few min it goes up to 12. Still while running it drops to 10 again.

i'm wondering if the MAF I got is bad, there was no change in its running condition when i changed it...or could the oil separator on the flame trap system be plugged up since the vac line was busted and its not getting the little extra airflow it needs. i checked the o2 sensor as well and its covered in carbon / soot. Its new, like 2 weeks new, could that cause false readings? the one for the gauge is also covered and it seems to be working fine.

also whats the thing in the fresh air intake called where the flametrap system hoses connect to called? its covered with oil residue on the outside...

what about running with no o2 sensor? I know i'll get a CEL but will it drop back to lookup tables until i can figure this out? 15MPG is kinda hard to take

thank you!

 

All the intercooler hoses good?
Maybe the Mass Flow is bad.

If you are running higher boost gap the plugs to about .028 or so.

 

Thanks tech, I'm ordering a new MAF.

Also the rubber return line from the pressure regulator is kinked. The original was leaking and I replaced it with regular piece but the bend is too tight and it seems pinched now. i have ordered the correct hose from Volvo, however I cant seem to find what the pressure is suppose to be, I'm going to hook my tester up later tonight...

 

OK so I put a new MAF in and no change. I also fixed the fuel pressure regulator hose, no change. the fuel pressure is sitting at 36PSI at idle, it was that way before the hose change and after, that's when it pumping the black smoke the most....I also disconnected the O2 sensors and no change. I'm pretty much stumped now....

I'm ready to take it to a shop and say FIX IT.

 

Check the idle air control valve. You can use a multimeter to check the voltage at from the ecu(open circuit) IAC disconnected and (I did this not to long ago but can't remeber the exact process) you can check it in circuit.