ok so im looking for some help with a 1994 volvo 850 turbo that is a backwards nightmare.it is my father in laws car and used to be mine, so here is the story, bought the car and was great for about 2 years, about 3 months ago the fuel pump went out (ie no fuel pressure), so i went to my local junk yard and pulled one, installed and ran great again, now here's where things get funny about 2 weeks ago i was in the cars passenger seat and noticed it running a little rough, so i scanned the car and to my shock there were 12 codes from the obd2 port with a generic scanner(codes listed below), so in law took it home because it honestly only seemed like a misfire at idle, and about week goes by the car was driven home and parked for about 2 days, and the 3rd day the cars battery was dead so the battery was put on the charger, the car will not start since the and now the only code that shows is P0120 along with a blinking overdrive light(arrow light). the car cranks and there is fuel pressure, but no spark from coil i have a pretty vast supply of parts from a awesome local mechanic that has his own volvo junk yard, so i have tried and tested a lot of things, one of the weirdest things i have found so far is the fact that the car has a obd2 port and a obd1 port and when a volvo scan tool is used it will not communicate with the car from ob2 and sadly we could not find the connector for obd1 for the scan tool, and here is what i have done so far...

tested spark from coil:no spark
tested connector to coil (3 wire) tested fine
tested crank sensor tests fine

swapped
ecus
coil packs
cam sensors
fuel relays(by fan)

i'm completely lost on what to look for next, i saw on another post that it could be an acceleration sensor but i cant find what that sensor actually does or if it will effect starting? every tec i talk to saw cam sensor but i have swapped 3 different ones from junk cars, i have ordered a new one but have yet to receive and test it, but i don't think it is the cam sensor, and for some unknown reason i wanna test wires from ignition cylinder on steering column, but haven't found a schematic for it yet,anyone got ideas?


12 codes from above

P1418 Secondary Air Injection System Relay 'A' Control Circuit High
P0400 Exhaust Gas Recirculation Flow Malfunction
P0300 Random Misfire
P0302 cylinder #2 misfire
P0303 cylinder #3 misfire
P0305 cylinder #5 misfire
P1310 Igniter Circuit Malfunction No. 3
P0172 over reporting" Mass Air Flow Sensor
P0103 Mass Airflow (MAF) Circuit High Air Flow and High Voltage Output
P0137 O2 sensor
P0141 O2 sensor
P0120 OBD-II TPS sensor

 

what codes do you get from the ODB1 diagnostic port (the LED with jumper box in front of the #1 cylinder)?

Check out volvotips.com for a list of diagnostics

 

which jumper's should i check? on youtube i saw a video on how to check and they used jumper A2 for engine codes i believe, and was pretty straight forward said to turn key, insert jumper and push button for a sec or 2 and release and the led would blink a code, however when i tried that, as soon soon as jumper was inserted the led was dimly lite, and when button was pressed the light got normal brightness and when held for many different intervals of time(ie 1,2,3,4,5,6,7,8.9.10 seconds each time) the light never blinks a code. so yes i have checked can not get a code

 

No problem.

First, the main fuel injection relay was built with torpedo-shaped plugs which use the volvo wiring plug that is famous for disintegrating. The first volvo that I ever saw with no spark, this was the problem. Old age. This causes no spark. It also causes the OBDI port to fail with a dim light which is only bright when you push the button. What a useful diagnostic. I don't mean swap the relay. I mean you have lost the ability to plug it in and actually get power. That is your current problem, no question.

After you fix this for 10 cents, whatever you come up with, you may also have to fix the original problem, of course.

 

so which is the main fuel relay then? cause i have tried swapping the ones on the fan shroud, to no effect, and i will try on saturday and can report back just don't know which one?

 

OMFG thank you that's exactly what it was I traced the wires for relay and found the bad wire car then fired right up, it still only produced the p0120 code and I was able to clear it so I guess we will see what pops up if any codes do, I was able to test obd1 port and on A2 to gave me code 111 even though no check engine light was on, but what jumper is to test engine codes??

 

yes socket 2 is for check engine codes. if you get a 111, there are no stored CEL codes.