My 1996 850 morning cold start is getting harder by the day. After starting and hitting accelerator, doesn't catch up. After driving car runs great. Hopefully she can make it through another Chicago winter. If not she has served me well and for that I am grateful. Any tips on where I should begin troubleshooting would be appreciated.

 

Coolant temperature sender is a known common problem on these cars. You can plug in to the OBDII port with a scan tool and you can see the temperature the car thinks is correct. You can second guess easily, where the car cannot. it doesn't have a backup reference. You could just replace it if you don't want to figure out whether it's okay.

 

I would start with the basics. Worn spark plugs will cause hard starting. How old are the rest of the ignition components? Then as others have suggested a scan with a compatible tool, and compare live data with the real world.

 

Thank you....

 

Had all parts associated with a tune up January of 2020. I need to invest in a scan tool. Any suggestions. Had the car scanned at Auto Zone and came back with the
same code prior to tune up.

Thank you.

 

you should be able to find date codes on your spark plug wires - if they are older than 5 years time to replace. If you are a new owner to the car and don't have a good maintenance history, doing a "stage 0" is a good idea - plugs, wire, cap, rotor. My only tip is you may want to pop off the air box for easy access to the screws that hold the distributor cap. Don't spend extra on plugs, good ol' copper cores work fine, and if in doubt, go genuine Volvo. Take note of what your plugs look like - wet/oily black or tan/brown? Are all the plugs looking the same?

Next is you may want to simply do preventative maintenance on the cooling system. Since you need to pop off the thermostat cover to reach the ECT, I'd simply replace the sensor, thermostat and the coolant reservoir cap. That should run you $75-100 US if you shop at a Volvo friendly site and can be done without draining the radiator. worse part of the job is figuring out how the ECT connector unhooks :-).

After that, you may want to rent/borrow a fuel pressure gauge and make sure you have proper pressure at the rail. Check Youtube for RobertDIY's video on how to do this and what the correct values are.

 

Thank you for taking the time.

 

A lot of people use torque app, but I personally cannot because that is android only. Very popular. You could get a scangauge. They are desgined to use full time, but for the money, they're pretty darn nice as a scan tool. but anyway you could use it to display coolant temperature, that's what it's designed to do. Not sure what other good options there are.

Personally I use an autoxray; they were bought buy SPX service solutions years ago, so not the same. Can't recommend an actual tool. I suppose lots of them are good. Innova looks good for the price.

I am not a fan of codes and code readers. Not at all. As you can see, the car doesn't set a code for being wrong about coolant temperature. It doesn't have anything to check against.

 

Just ordered the torque obd II from Amazon...very affordable.
Thanks again...

 

It will if it takes too long to warm up (thermostat stuck open in winter is a common cause) or if it stays too hot too long you will get a temp sensor code. .

That said I have replaced a few temp sensors that would make the car hard to start cold - only after making sure everything else is perfect. This was usually the 2001+ cars, maybe for earlier cars also, but that was a long time ago...........

 

I did the watch the temperature gauge after turning key in the morning test....low and behold the gauge moved....I think that's where I'll start...thanks

 

start by unplugging the ECT on a cold engine and measure the resistance. It should be 2500 ohms give or take (assume ambient temp is about 70F). On a hot engine, the resistance will drop to something in the 200-300 ohm range.

 

Thank you for the advice.

 

Yes sir, you were correct. It was the temperature sensor. I had to stop and collect myself because I was afraid of stripping the screws that secure the housing. I went ahead and changed the thermostat also.. The thermostat had to be the original because it was beautifully detailed. I knew that had to be the issue because once installed and I turned the ignition key I didn't get that instant bump from the dashboard temperature gauge. Thanks again for pointing me in the right direction.

 

You were correct. Thank you again.