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993 c2s not starting if ignition is left "on" for more than 30 seconds
This is a very strange situation that I've had trouble searching and finding more information on.
My 1998 C2S, 73k miles, starts right up, every time, if I turn the ignition to on, and crank it right away.
However, if I turn the ignition to on, but let it sit for 30 seconds or more, then crank the engine, it just cranks and cranks but never fires and starts. At that point, I can turn the ignition all the way to off, then right back to on, crank right away, and it fires up instantly.
My indie mechanic told me to try holding the throttle to the floor as I crank when it happens, but that didn't change anything either.
for what it's worth - I have a focus 9 solid-state DME in it (no fuel pump prime), but the factory DME which still works, had this issue as well.
The prior owner had the immobilizer disabled/removed, but unsure of how - wondering if this can cause similar issues.
Wanted to do a quick check to see if anybody has seen this before. It is now currently with my mechanic being troubleshot, but if anyone has seen this before and has quick suggestions or knows more about potential causes, I'd love to hear them! I thought maybe it was a fuel check valve leaking fuel pressure down while it sat, but my mechanic feels it may be more electrical related. Hmm.
Hi Kertong,
The DME relay is subject to heat as its internal solenoids, there are two of them, are powered when the ignition is on generating heat. It may be a failed solder joint in the DME relay that once warmed up fails to make a connection.
You can just replace the relay or pry the one you have ipen and inspect its solder joints.
This may not be your problem but is clearly the first place you should look.
Andy
Hi Kertong,
The DME relay is subject to heat as its internal solenoids, there are two of them, are powered when the ignition is on generating heat. It may be a failed solder joint in the DME relay that once warmed up fails to make a connection.
You can just replace the relay or pry the one you have ipen and inspect its solder joints.
This may not be your problem but is clearly the first place you should look.
Andy
thank you! yes, i have tried two DME's (one original one, one solid state one from focus 9) and both are exhibiting this issue. My mechanic (a guru i trust with my 993's life) is saying he is leaning towards the immobilzer/driveblock system and trying to figure out how it was removed/disabled.
Will keep this thread updated once we find the solution. thanks!
Sounds exactly like an immobilizer issue. Are you certain it's been disabled? I'll bet if you get a complete relief of symptoms if you get the plug in immobilizer advertised here.
For me, the solid state relay removes the DME concern. I don't think Andy's solder heat situation is likely.
Sounds exactly like an immobilizer issue. Are you certain it's been disabled? I'll bet if you get a complete relief of symptoms if you get the plug in immobilizer advertised here.
For me, the solid state relay removes the DME concern. I don't think Andy's solder heat situation is likely.
-Scott
Ah, thank you Scott. I saw that there's a solution called IMMO BLOCK that plugs into the door chime relay. I may give that a go. I just got this car a month ago so - it is almost 100% stock, but going through the service history, there is paperwork indicating the immobilizer was defeated; not sure if it was via a plug in device or an ECU reflash; or even a hack on the immobilzer unit under the seat. My mechanic is going through this now apparently, will keep this thread posted! Car has been a champ in all other aspects.
OK, "The prior owner had the immobilizer disabled/removed, but unsure of how - wondering if this can cause similar issues."
This may have involved both changes in a controller and or changes in the fuse box. If you can look at the controllers, both the immobilizer and the DME you may get the name of who did the disabling off a label on the box or internal chip and get some insights to unwinding it.
And if you do figure it out the IMMO BLOC is the way to go. I have had it on my car car for quite a while: https://993servicerepair.blogspot.co...p-key-fob.html
Andy
My indie mechanic told me to try holding the throttle to the floor as I crank when it happens, but that didn't change anything either
to me , it looks like it is an immobilizer thingy, but what your Indie said, is un-orthodox in the 993 system. Flooring the pedal to start an M64 is the worst thing to do to the engine managment.
to me , it looks like it is an immobilizer thingy, but what your Indie said, is un-orthodox in the 993 system. Flooring the pedal to start an M64 is the worst thing to do to the engine managment.
oh, interesting. it was something he suggested I try when I asked him if it could be fuel pressure bleedoff related - if that was the case he mentioned the engine could be flooded and this would be one way to confirm the scenario.
if I turn the ignition to on, but let it sit for 30 seconds or more, then crank the engine, it just cranks and cranks but never fires and starts. At that point, I can turn the ignition all the way to off, then right back to on, crank right away, and it fires up instantly.
This is by design, starting with MY96. Curious why you would need to do this?
This is by design, starting with MY96. Curious why you would need to do this?
Whoa, thanks for the info. That's.. unusual, I don't recall this ever happening on my '97 C4S i had previously.
Oftentimes, I'll get in the car, set the ignition to "on" to get the air and radio going, fiddle on my phone, take it out of my pocket and store it somewhere, wait for my wife to get in and buckle up, etc, etc. I don't always crank the engine immediately.
if this is by design, it's minor enough that I can live with it. But I feared it was indicative of something wrong, or failing, and I do not want to be stranded somewhere where the engine is in perma-crank-but-doesn't-fire mode, haha.
04-27-2021, 03:27 PM
993 c2s not starting if ignition is left "on" for more than 30 seconds
