I haven't been on here in a while, but I have a problem. I have a 1994 850 wagon with 2.4 N/A and it won't start. I had problems starting it last Saturday, but on the second attempt it started fine. It ran fine on Sunday and Monday as well, but on Tuesday, it would crank but not fire up. I checked the trouble codes and got the one for the crank/RPM sensor. I am sure this was from the last time I had a problem as I replaced that part less than 7,000 miles ago and I don't think I cleared the code. I then cleared the codes and cranked it over for a minute. I now get the 1-2-3 code indicating a faulty ECT sensor. Would that make it not start? I checked for fuel pressure and I can hear the pump run when I first turn on the key so I know it's not a fuel problem. I have no spark. Can anybody help guide me if the ECT is not the cause of my problem? I did notice that the check engine light blinks at me when I crank it. I have never seen this before. Any clues? Thanks for any help.

 

I have never had a ECT sensor problem but if you don't have spark you could have several issues. If the code said ECT I would replace it.

 

[QUOTE=wyd-open;339958] I checked for fuel pressure and I can hear the pump run when I first turn on the key so I know it's not a fuel problem. /QUOTE]

Did you actually check the fuel pressure to make sure you have some or did you only listen for the pump ?? Hearing the pump run doesn't guarantee you have any pressure or volume up at the rail.

But no spark is no spark.
A flashing CEL usually means that a serious misfire of one or more cylinders is currently in progress. Did you check for spark at the end of one of the spark plug wires and or from the coil lead ??

The coolant temp sensor should adjust the timing and fuel delivery according to the map in the computer. If the sensor fails you should still have fuel and spark but you would likely be running richer as the computer is designed to go rich if the ECT sensor fails.

 

If you have a bad ECT, the car will have difficulty starting. Timing advance and fuel curves are indexed against coolant temperature in most vehicles. Most ECT failed sensors that I have come across not only give an incorrect tempt reading but they give the ECU a value that is way off (my old DSM used to give -64*F for example! when the ECT sens failed) so when the ECU tries to use this value, the cold start enrichment is way off causing hard starts. My 850 would start eventually (with a bad ECT sens) but it took almost 5-10 mins of cranking. This immediately went away after replacing the ECT sensor

 

I did take the cap off the schrader valve and pressed it with a screwdriver. It sprayed out with pretty good pressure. I checked for spark off the coil wire and got nothing. I will try changing the sensor to see if that solves the problem. Thanks for the info.

 

Check your fuse box under the hood. check the top few (top as in closest to passenger side) If one of those is blown, replace it, then lock the car with the key twice, then unlock with the key twice. If the car went into some sort of security mode it blows a fuse when you try to start it, and cuts spark and power to the injector.

Given the circumstances I'm doubting it's that, but its something that only takes 30 seconds to check out. keep us posted.

 

I just checked all of the fuses and they are good. Thanks for the tip though.