keep having problems with 850 starting

idigvolvos · Post by **idigvolvos** » 30 May 2012, 22:00

My 1996 850T has had numerous times where it has had problems starting. It has happened about 5-7 times over the last year. It will crank but won't start. The first time it started by adding starter fluid. The next two times I had it towed to 2 different volvo repair shops and they got it started and said that it happens a lot with this model, if you start it and run it for a short time. I did back it out of the driveway and turned it off one of the times and it wouldn't start the next day. One shop did replace a temperature sensor that they said could make the engine think it"s running colder and then it would add more gas causing problems. They also checked the fuel pump and said the pressure was normal. Seemed fine until it wouldn't start again (about a month later)and then starting fluid did get it going again for a day and then it wouldn't start again. This time the starter fluid would get it going but it would die shortly after, even while holding down the gas pedal if you let it get below 3000 RPM. We did disconnect the gas line to the engine and there was no gas coming out but the car started right up after wiggling the line and then died again after it was reconnected. The fuel pump relay was also replaced but didn't seem to make a difference. Anybody have any ideas? COuld it be the fuel pump? Help is much appreciated!

Post by **jblackburn** » 31 May 2012, 08:39

There's a grey fuel injector relay on your 850 on the fan shroud near the battery.

The wiring to this relay can become tempermental as it wears out; sometimes providing power to the relay and sometimes not. If it acts up again, poke at the wiring a bit and see if the car will fire up on its own.

idigvolvos · Post by **idigvolvos** » 31 May 2012, 21:24

I tried wiggling the wires to that relay, but nothing happened. Any other suggestions? Thanks!

Post by **Ozark Lee** » 02 Jun 2012, 14:56

If you can get your hands on a fuel pressure gauge (you can buy one at most auto parts stores for around $30.00) hook up the gauge and check the fuel pressure with the key turned to position II.

If you are getting good pressure then leave the gauge hooked up and turn the key off and observe the pressure. It should not fall rapidly to zero. If it does quickly fall to zero then there is either a problem with the fuel pressure regulator or with the check valve in the fuel pump.

...Lee

jgray850turbo · Post by **jgray850turbo** » 04 Jul 2012, 19:43

I would try the fuel pump.
I have a 95 850t and have had several starting/running issues for the last two years, especially warm and after stopping. Replaced vacuum lines, cleaned everything, tune up, small improvements but still persistent problems. It finally began to not start on occasion, checked relays, traced it to the pump. I replaced it, expecting it to just help the primary starting issue, but wow, what a difference. It fixed all my symptoms, including what I thought was a failing or weak turbo. Now she is really accelerating. One thing I noticed was that the pump had lowered inside of the 'cradle' or case it's in and the hose was barely touching the fuel line. I think it may have been causing intermittent delivery issues and allowing back flow. Their not very expensive, pretty easy to fix, and at the car's age, really couldn't hurt.