This is the second time I have posted for this problem and I really could use some advice before I give up and take it to the Volvo Service Dept. The problem started during our cold weather (<20 Deg F). The starter cranked over fine, and it would fire once, then nothing. Each time I let off the key and tried again it would do the same thing. I tried until the battery went low. I recharged the battery and tried again, no luck. Went out the next day and it started immediately. I have replaced the plugs and wires. Seemed OK for a week or so then it did it again. I found when it did this, that if I alternately pushed the pedal to the floor, tried it, let off the pedal and tried it again a few times I could usually get it to start. Once it started, it would run rough for a couple of minutes then would be fine. I have since noticed another symptom I feel may be related. Whenever I have had this problem, I notice the (radiator) cooling fan is running, even after I remove the key. When I finally get it started, the climate control fan comes on full blast right away (it usually does this after the engine has warmed up). It seems that if the cooling fan is running when I shut the car off after a drive (keep in mind it's well below freezing outside), the next time I try to start the engine cold I have the problem. If the fan shuts off with the engine, the car starts fine the next time. Questions:

Does the engine temperature sensor tie into the air/fuel mixture for starting?
I suspect I may have a vacuum leak (P0192) but would this lead to intermittant problems like this (Iv'e had this error for a long time with no apparent start/run issues)?
I have searched this site and never seen a temperature sensor affect start/run. Has ANYONE ELSE HAD THIS SYMPTOM?
I'm going to try finding a vacuum leak today before the next snowstorm arrives, but my gut tells me this is not the solution. HELP PLEASE!!!

 

Intermittent No-start or stalling is difficult to diagnose. My suggestions:

1. Get a code reader and read any codes stored in the system.

2. A common culprit is the Fuel Pump RELAY.
When dealing with no start and suspect fuel relay, Jump terminals 15 and 87 of the Fuel Relay Connector (driver's side fuse box under the hood, near the windshield):
http://volvospeed.com/vs_forum/index...t-be-bypassed/

If the car starts nicely after you jump terminals 15 and 87, then your Fuel Pump RELAY is bad.

3. I recently had similar symptoms. Truned out to be bad Air Mass Meter: code P0103.
Bought a new BOSCH (yes use Bosch only) Air Mass Meter from "germanautosupply" ebay seller for $145.
All is good now.

4. And Yes the Coolant Temp Sensor (CTS) located right on the thermostat housing can be bad too. Use only Volvo CTS.

HTH

 

Thanks HTH! I have thought I was getting fuel, but that is worth a try. I'll post attempts & fixes (hopefully) so that this might be of use to someone else too.

TX

 

Sounds like it might be a bad ECT to me as well.

 

Forgive my ignorance, but what is an ECT?

 

CTS = Coolant Temp Sensor
ECT = Engine Coolant Temp (Sensor).

Basically the same thing, different terms!

 

I had 2 problems biting me at once. First, I found 2 vacuum leaks, on either end of a vacuum line to the cruise control and another one which which I think goes to the exhaust recycle/fast warmup. When I replaced the lines, the engine no longer raced right after starting (it's done this for some time). Second, I replaced the engine temperature sensor. By suggestion of another post, I disconnected the battery about 20 min prior to replacing the sensor. Since doing this I have not noticed my cooling fan coming on when the engine is cold, and no problems starting the car. My Check Engine Light has gone off too! It has warmed up outside, so I suppose I should wait until we have another really cold night before I officially call it fixed, but no problems for a week now.

 

Glad it is better now!

 

I love a happy ending (hopefully).