hey just bought a 1994 turbo wagon and it runs awesome before it gets warmed up. after its warmed up it goes into limp mode and throws codes:
A3 155, 135, 235
A6 224
B3 122
Does anyone know where there's a complete code redout? i searched but with limited results.
PS. thought it was the o2 sensor so i pulled the turbo. o2 was completely fried because the turbo was blowing oil out both ends. rebuilt the turbo and wired in a 3 wire o2 sensor. Things i'm going to check next will be the maf sensor, knock sensor and the grounds i guess.
Not really sure where to go next its gotta be some faulty sensor cause like i said when its running in closed loop mode (cold engine) she runs wild but after its warmed up and in open loop its in limp mode.

 

ok so here's the codes i could find as per https://volvoforums.com/forum/volvo-850-16/list-diagnostic-trouble-codes-dtc-9856/

Using Motronic 4.3 system A2 shows...
155 - faulty no 5 fuel injector
135 - faulty no 3 fuel injector
235 - EGR controller signal absent or faulty
224 - ?
122 - ?

This confuses me because there is no cylinder no5 does this code mean something else? i will go and clean all the injector connections tonight, and will see if i can find a set of new ones somewhere. Anybody have other suggestions of what to check? thanks!
going to try the oil trap clean and then we'll see...

 

I believe you are looking at the Motronic 4.3 which was used on 850's hence the 5th injector...You need to be looking for codes for the LH Jetronic. Invest in a Bentley manual they have them at www.amazon.com and I believe www.ipdusa.com

I assume that codes were checked fairly recently, meaning while this problem was happening?

Here are the steps I would take if I had the car in my shop, and unfortunately, unless you have some specific test equipment, this may be something that is best left for a good independent Volvo shop. I know that you're looking for a quick magic-bullet answer here, but most times, there is none, but I can at least get you pointed in the right direction.

1. read out codes from LH injection system (socket 2)
2. read out codes from ignition system (socket 6)
3. If any 3-digit codes are stored, I can direct you through some troubleshooting steps related to that specific code
4. if no codes are stored, then I would connect a fuel pressure test set, and monitor injector rail pressure as the problem is happening
5. if fuel pressures are correct (about 43 psi while idling with regulator connected), then I would start looking at the ignition system for a good clean spark

I can guarantee that there is a problem with one of the 5 items above. In order to help you further, I will need to know which item has failed.

 

i plan on replacing the cap/rotor and spark plugs(just cause they're relatively cheap), i have the throttle body apart and am cleaning this and the oil condensor. Reason being is the turbo was blowing a ton of oil through the whole system and i thought maybe it was caked on these parts.

ps. i also found a vacuum hose i thought i had fixed that was cracked in half.
also there is a hole on the block above intake runner 3 that looked suspicious like it had a hose connected to it? I'm new to volvo's and have no idea if something was supposed to be here. its about 1/4" dia and on the flat top part of the block next to the valve cover. i'll keep posting updates...

the injector rail pressure i was assuming is good just because it runs amazing before it gets warmed up but i will check to see if the pressure is good.

 

Changed the cap, rotor, spark plugs and wires, cleaned the throttle body and tps sensor, cleaned maf sensor, cleaned out oil condenser, pulled out the charcoal canister cause it was completely clogged and just capped off the two vacuum lines going to it. Found a vacuum line split in half i thought was fixed and an injector that wasn't plugged in all the way. also cleaned knock and a few other connectors. Not sure which one in particular was causing the problem just that its fixed

she seems to run awesome. still throwing some codes but the ac crap is toast and the brake booster went out. but at least she hauls *****! i will post a pic so you can all see her. considering i bought it for only 600 i dont think i came out too badly.

 

Got this for my gf from a guy in derby, ks for 600$. put a battery in it and turbo rebuilt. he didn't even know it was a turbo. so all in all i'm in for about 900-1000 dollars. not too bad i dont think. and she likes it and its safe so i'm happy. thanks erbody.

 

You are letting your girfriend drive a $600 car?...J/K...she's lucky she has a car and yes it's a good deal if it runs...

 

I think the 940 Turbo wagon is a thing of beauty. My '94 still turns heads, either in amazement at the body lines or wonderment why I would ever drive something like that. You bought a true classic and worth putting the time into.