I don't know anything about how the cold start works but from what i understand it's like a choke for more fuel at first, anyway the car starts ok and idles fine but if you push down on the pedal it spits and sputters and you need to fight it to get any rpms but after it warms up most of that goes away but even then it acts like it wanting more fuel so my thought is the cold start is not working i don't know what else would cause this, i would appreciate it if someone can tell me how it works and what to look for, i would expect this condition in winter but it is not cold now i am puzzled. thanks ron

 

This sounds like a bad MAFS (mass airflow sensor). Does a 960 even have a cold start injector? It is an old 240 thing.

 

Yes more fuel is needed when cold. That is controlled electronically. Engine temp, air temp, mass of air going into engine, RPM, throttle position, cam position. - With all of those parameters the engine control unit determines when and how much fuel to inject.

For your problem - There are many possibilities, could be a bad temp sensor, computer thinks it's 150 degrees outside or engine is 220 degrees when cold - then it will deliver a lean mixture. Maybe a simple bad intake manifold gasket, or a leak in the pipe from the air mass meter to the throttle plate, or a bad air mass meter. It just needs to be diagnosed. Start with checking for self diagnostic codes, checking for intake air leaks - simple things first.

It's a common fuel injection system - are you trying to fix this yourself?

"Does a 960 even have a cold start injector?" - No it does not.

 

you can also test your temp sensor's resistance with a simple volt-ohm meter. Google for a resistence by temperature table.

 

thanks lev i had the MAF go bad once long time ago and it showed up in codes right away, this has been a very difficult vehicle to work on to begin with it id very difficult to find info and especially correct info i have sent back a lot of parts that were wrong 92 and 93 are pretty much the same but that is about all. My codes tell me cam sensor and front knock sensor and i replaced both about three times and it ran well with those codes for many years, it starts easy and idles smooth but when you move the pedal it spits and sputters like it is short on fuel my pressure stays right at 44 lbs,it has now taken to idling fine for about ten or more minutes then dies and will not start until it sets for about the same amount of time so something must be getting hot and quit. I have really had to rely on you folks for info the manuals are vague and often incorrect. thanks again ron

 

The OBD1 system on these cars is unreliable, better than nothing but not by much. Rarely can you get a code, change what it says is wrong on be done. I am not great with 960s, and they are generally unloved because they are complicated and as they aged they became unworthy of being maintained. What I like about Volvos was their simplicity and reliability, the more involved a car gets, the harder it is to keep it alive as it ages. Today's techno luxo boxes won't fare well. I digress. The symptoms you experience are spot on MAFS failure for a B230 Volvo motor, if that helps.

 

Codes do not mean a part is bad - they mean the computer does not like the signal from that part. The signal is outside normal parameters and might make the car pollute. For instance the OP "replaced his front knock sensor about three times" - I guess he got a code and - yep let's replace the part (even though I've never seen a knock sensor make a car run bad, they are not that powerful, and can't change the timing very much)

Had a car once started setting knock sensor codes after it was overheated and a valve job/head gasket was done - engine was noisier than before, maybe piston slap - and set knock sensor codes. Customer didn't understand why we could not fix it with out spending a whole lot more - because they had just spent a bunch fixing their head and the coolant leak that caused it.

Actually it was the driver that "just drove it to the next exit" that caused the blown head gasket.

 

Ev I am sure you are right about the MAF, when i disconnect it the car starts running a lot better so i am going to get one but there is another issue i think because the car will run for 15 min and die and will not start back up until it has sat about 15-20 min that tells me something is sensitive to heat, i am thinking ECT sensor but i would like to have your idea on that; fuel press is fine plugs are good i don't know what else to check right now. thanks again Ev i appreciate your help

 

thanks mt6127 I think the temp sensor is a likely problem with this car one reason i think so is the car will start and run about 15 min then die and will not start for another 15-20 min this telling me something is sensitive to heat, i have found the MAF sensor is bad but i don't think it would relate to heat. thanks again ron

 

Honk I have found the MAF sensor to be bad but the car will run for about 15 min then die and no start for about 15-20 min that is telling me something is heat sensitive so i am going to check the temp sensors, i don't know what else right now. thanks again ron

 

Have you checked fuel pressure? Put a gauge on it and see if the fuel pressure drops off right before (or slowing goes down) it dies?

Temp sensor for air is in the AMM, water temp sensor will not make the engine stop running.

 

hoonk thanks for getting back to me, fuel pressure is right on, is there anything in the system that would restrict the fuel injectors themselves because when the car is running it acts like it is starving for gas, i have not gotten to check the temp sensors yet i hope i find something that is causing these problems. thanks ron