2001 C70 convertible. Intermittent crank but no start Topic is solved

[Pmckib]

I bought a 2001 Volvo C70 convertible about a year ago for $1000. Car had 55,000 miles (yes it's 55,000 miles). It would crank but not fire but. For $1000 I figured I'd take a chance. I replace the antenna ring, reset the anti theft system with the unlock-lock/ key to on 5 times and the car fired right up. All was good for about 3 months when the no start returned. Car would start then die after 2 seconds. I have 3 keys and the problem is the same for all three keys. The problem only happens after the car has been driven and then shut off if you try to restart it within an hour it there's a 50/50 chance it won't start. The reprogram procedures works most of the time but sometimes you'll have to do it 2-3 times before the car starts. I pulled the new antenna ring off the car and replaced it with the original antenna ring and the car has the same problem. I cleaned the contacts on the wiring harness but the problem remains. I live in FL and the no start issue seems to be more common in the summer when it's hot

Other Volvos owned
1999 C70 Convertible
2003 V70
1995 940 turbo
1990 780 turbo

[volvolugnut]

What is the state of the ETM (electronic throttle module)? If original ETM, it is likely failing.
For quick check, open the hood and turn key to position 2. Quickly go listen under hood for a soft buzz near ETM. It should buzz for maybe 30 seconds then go silent. Try this after a no start condition.
I had a hot no start problem like this on my 2001 V70. A new ETM from Xemodex fixed it.
volvolugnut

[Pmckib]

I don't think it's the ETM. The car will start but stalls after 2 seconds. If you try to restart it after that it's a crank no start. If I wait 2 minutes and lock then unlock the car 3 times then insert the key in the ignition and turn it from off to position 2 then back to off 4 times, then turn the key all the way to start the 5th time the car the fires up and all is good. The problem is not specific to a single key but has occured with all 3 keys.

[jmartin919]

@Xanthefin may be able to help with his 850OBDII app.