Hello guys,

Recently bought a volvo 850 GLT (1992) 2.0. The car ran fine but the previous owner didn't use the car to much, and it was stopped for a while.
After a few days of use, the lambda light turned on. The car began loosing rpm when it came to a stop, and the engine would die sometimes. If the car was on the move it worked fine.
I did the required maintenance, oil filters, and checked the car overall. Also replaced de o2 sensor to no avail, as the car still showed the lambda sign.
Now i know that the lambda sign can mean a multitude of problems, i checked beforehand the cars codes and the ones related to this problem. The codes were:
A7:
1-2-2 - Air temp sensor signal.
1-3-2 - Battery voltage
2-3-1 - Lambdfa adjustment
A2:
4-1-1 - Throttle switch signal faulty or missing
These codes are according to this website Volvo – TroubleCodes.net.

Now since i replaced the o2 sensor, and cleaned the codes, the lambda light is still on but the car ran fine without hiccups. Until recently when i was accelerating and the car started loosing power and almost cut off. The car is still running, but as soon as i start giving to much gas it stars loosing power and the rpms go down. I also noticed that it might be backfiring a little and running on 4 cylinders instead of 5 for a few seconds.
I assume that the problems is related with injection, i will start by changing the spark plugs as they are a little used, but i don't thinks that's the cause.
If someone could point me out in a direction of what stuff i should be looking, for what might be the cause of these issues it would be great.

Besides this stuff been loving the car, nothing like a 5 cylinder purr.

 

If you erased all the codes and the warning light is back on there are codes stored - what codes came back?

 

So i went to check the codes, and the car wouldn't start. Tried it multiple times it almost ran but didn't have enough power to continue. Anyways the codes that come up now are:
A2:
1-2-1 - Mass airflow sensor
2-2-3 - Idle valve signal
A6:
4-1-1 - Throttle switch signal faulty or missing

 

You might have a big vacuum leak. Or in particular a big leak between the air flow sensor and the throttle. The first volvo 850 I ever had experienced exactly this problem. One of the rubber sections of the intake piping developed a big hole and the car lost control of its air measurement entirely. It quickly got worse enough that it wouldn't run.

 

Is there an easy way to find a vacuum leak? The codes that are showing up could be because of this?

 

start with a visual inspection - check around the vaccuum tree first (its under the throttle cable spool cover) then track backwards from the throttle body inspecting the big air intake hoses. If nothing obvious shows up you need to do a smoke test. Most shops have a machine to do this but you can go on Youtube and search for RobertDIY's vid on how to make a home made smoke machine and do some basic tests.

 

Yes a smoke machine is best - but you can use carb cleaner - pinpoint spray areas possibly leaking with the engine idling. The idle will change sometimes only momentarily (due to the auto air valve correcting) if the engine ingests carb cleaner.

 

+1. One place to check with carb cleaner is around the injector seals. 20 year old OEM seals are probably hard as a rock!