Cranks ok but no start 98 V70 turbo

[jmartin919]

Duhh. I'll do that and report back.

[jmartin919]

Yes, the ECT sensor is used by the dash temp gauge. Any guesses as to why a scanner might get a very different value than what shows on the gauge?

[abscate]

The dash gauge is very coarse. It’s basically a cold hot too-hot gauge

The ECU divides the voltage returned by the ECT into 255 bits and returns real information

[jmartin919]

It was 50 degrees. The car had been sitting over night. The dash gauge showed minimum as it should but the scanner said something like 114. When I try to start the car it revs up and immediately dies. I was thinking the ETC may be bad since the scanner shows 114 which would explain the condition. I thought the dash gauge would at least show that temp, maybe not.

[abscate]

Yes, that’s a bad engine coolant temperature sensor. Bit tricky to get to but easier on a 98 than a 99!

[Chuck W]

So, I think we may have a confusion about what the "dash" gauge you're referring to actually is. At least it sounds like it to me.

Are you talking about the coolant temp gauge, or the gauge in the little trip-minder, clock, temp gauge screen at the bottom of the cluster?

The coolant gauge uses the ECT, as does the ECU for temperature. The LCD temp "gauge" get's info from the ambient/outside air temp sensor, which is located in front of the radiator in the open air. This also is used by the ECC for the heating/cooling.

[jmartin919]

Yes I'm talking about the coolant temp gauge on the dash. If I unplug the ECT the gauge bottoms out and the scanner reads -40. The ECT seems to be erratic. Yesterday morning it scanned the correct temp, about 45 F. Day before it said 114. I'll continue to check for the next few mornings.

[Chuck W]

Ah, OK. Just checking.

As mentioned, the coolant gauge is pretty coarse, and 100*F is still fairly "cold" as far as a factory coolant gauge is concerned.

The issue does sound like a pooched ECT sensor.

[erikv11]

Back on topic there, regarding the no-start V70 in the thread title:

Today I drove it home for lunch, then back to work 20 minutes later, like 10 miles total. Came out to drive home, no start. So this episode shoots holes in my heat soak speculations. Tried unplugging the MAF anyway, still no start. Checked fuel pressure: 0 psi. Swapped fuel pump relay, still 0 psi. Car is sitting in the lot at work.

I'll grab a for-sure working fuel pump relay from my 850 and try it too, and eventually put a voltmeter to the connector, but it's now looking like a fuel pump failure.

That would mean this O-Reilly Auto Parts fuel pump (maybe Import Direct brand?) lasted a mere 8,100 miles and two years (26 months)! Good thing I just got the car back from my daughter.

[Chuck W]

erik-Have you tried waving your hands over the main FI relay up by the fan? (I didn't see that in your posts). Is it at least clicking when you try and start it?