Trouble starting after rolling the car forward/backward?

[jawn101]

This is a weird one, but it's the second time it's happened. My garage door spring broke today, and I had to roll the car slightly forward to get access to it for replacement. It was all of 2 feet, so I just released the parking brake and pushed the car, in neutral. Then, once the door was moving again I rolled it back into place - again, just in neutral. A few minutes later I needed to start the car to let the repair guy get at the opener at the center of the garage, and it wouldn't turn over. Took a minute or two of cranking and stopping, cranking and stopping.

This happened once before recently on a day trip with David Proehl, where we rolled our cars into position for a photo opp and then I had trouble getting it started afterwards.

My car *NEVER* has starting problems normally. Cold or hot, regardless of engine or ambient temperature, running time, how long it's sat - even after a whole month of sitting it fires up after only a second's crank. Unless I roll it around, that is...

What on earth...?

[NightFlyer]

That's really strange. I push mine around in neutral frequently and haven't ever noticed anything like what you're describing. I wonder if maybe the way in which you're pushing it is having an adverse effect on the inertia switch??? That's about all I can think of that makes any kind of sense. Hopefully someone else will have some better insight into this situation for you.

[Bitsyncmaster]

I would guess you have an intermittent electrical connection and it's just coincidence it showed up after pushing the car. Way to hard to find those intermittents without more data (did the fuel pump prime?, did it fire at all?, etc).

By the way, "turn over" and "cranking" means the same thing to me. So I guess your engine cranked but did not start.

[jawn101]

Thanks guys. No intermittent electricals, I know that for sure!! Well, as sure as anyone can. Every single connection in the car has been gone over and shored up, stem to stern. :) Your RPM relay is in there Dave and yes, the pump primed every time I turned the key.

[Jonathan]

Just an idea Jon, and coming from an automatic owner as I see your car is a manual...

The cars won't start unless the gear shifter is in Park. Is there something similar on the manuals? I don't know, that's why I ask. I did the roll forward for some photos at one point and learned about the car not starting when I hadn't put it back in Park.

If it isn't a particular gear versus neutral, perhaps there is some common electrical aspect that isn't getting confirmation for whatever reason.

It does sound like it's related to an interlock of some kind that gets activated after moving the car when it isn't on. Is there any old alarm system remnants lingering in your car anywhere?

[jawn101]

Good thinking, but no - the manuals have no shift interlock. No alarm system. It's not like a binary "no start" - it tries and sputters.

[Jonathan]

Ok, understood.

So another odd coincidence thought... when you roll the car forward or backwards, who is doing the pushing and where are they pushing on? Not sure how this might work, but perhaps where they are gripping the fascia or door frame it is inadvertently pinching a wire, or like others said, somehow messing with the inertia switch? If you're doing the pushing and driving and braking with one leg and one out, maybe you reaching a leg in for the brake is bumping something you didn't realize under the footwell? Not saying any of these are too likely, just some more ideas :)

[djdogbone]

If this was a newer car, I'd say it's the Drive shaft positioning sensor

[jawn101]

Ok, understood.

So another odd coincidence thought... when you roll the car forward or backwards, who is doing the pushing and where are they pushing on? Not sure how this might work, but perhaps where they are gripping the fascia or door frame it is inadvertently pinching a wire, or like others said, somehow messing with the inertia switch? If you're doing the pushing and driving and braking with one leg and one out, maybe you reaching a leg in for the brake is bumping something you didn't realize under the footwell? Not saying any of these are too likely, just some more ideas :)

Great questions Jonathan, no harm in brainstorming with something this weird. It's always me, I just release the brake and push from outside the car, on the plastic infill panel around the front door striker. That way the brake is in easy reach to stop it. If it was the inertia switch, the failure to start would be more binary and wouldn't go away on its own. Once I get it started again, the issue doesn't recur. Like I said, this is only the second time I've seen it in 4 years of ownership.


If this was a newer car, I'd say it's the Drive shaft positioning sensor

LOL, well there's a pickup and a sensor... but they don't go anywhere... :)

[Jonathan]

So if it goes away on it's own once you get it started, it would almost imitate a hot start problem, without the hot part? And what I'm getting at is, could there be something getting jostled that would make your car lose it's fuel rest pressure? How much time needs to go by until it heals itself?

That's possibly just as far fetched, but knowing it goes away on it's own as opposed to you taking some sort of action might help narrowing it down. Unless there's some step that's easy to gloss over as forgotten that corrects the issue unknowingly.

Do you roll it forward with the key in the ignition? I would assume so to stop the column from locking. If not, would "cycling the power" so to speak reset anything? It still stinks of inertia switch to me for some reason...

EDIT: hand brake or foot brake you're using?

[jawn101]

So if it goes away on it's own once you get it started, it would almost imitate a hot start problem, without the hot part? And what I'm getting at is, could there be something getting jostled that would make your car lose it's fuel rest pressure? How much time needs to go by until it heals itself?

That's possibly just as far fetched, but knowing it goes away on it's own as opposed to you taking some sort of action might help narrowing it down. Unless there's some step that's easy to gloss over as forgotten that corrects the issue unknowingly.

Do you roll it forward with the key in the ignition? I would assume so to stop the column from locking. If not, would "cycling the power" so to speak reset anything? It still stinks of inertia switch to me for some reason...

Yeah, key is usually in the ignition. It goes away after I fight and struggle with it to get it started, then subsequent starts are back to normal, non-tempermental goodness. Turning the key on, off, on, to power cycle doesn't do anything to help.

I can't imagine what could possibly get jostled by a gentle roll forward, there's no movement there that doesn't happen when the car is under its own power - and it's far, far more gentle.

[Jonathan]

Cylinders don't move in the engine unless it is in gear, right? Don't know if them moving down a revolution or two would "suck" fuel through the injectors and lower the rest pressure.

If it has only happened a couple times in 4 years, can you recall how much gas you had in the tank at the time? Maybe if it was low enough, your rolling the car sloshed what was left in the tank enough to starve the fuel pump/pick-up hose/tuna can somehow?

Otherwise, it's almost bedtime... and us East coasters will chat with you West coasters tomorrow!!

[Rich]

I doubt anybody can come up with any relationship between hand-pushing on the infill panel, intermittent e-brake deployment and a non-start episode - and episode that later disappears.

While I know you did a thorough job on the wiring connectors and grounds when you first got the car, Jon, it's difficult to rule out something like a balky ignition switch, no? Or the connectors to it? Since the engine cranks and the f.pump is running have you tried checking the input voltage to the ign. coil during any of those episodes?

I'll put myself down as claiming that the rolling back and forth, in and of itself at least, is coincidental with the non-start, not a cause of it.

Always tricky to diagnose intermittents like this one but good luck anyway.

-Rich

[vwdmc16]

Even as a professional mechanic I have to ask WTF are you taking about?




If this was a newer car, I'd say it's the Drive shaft positioning sensor

[vwdmc16]

Wow Jon you are sure getting all the tricky things I need to come over a fix.

Have you started the car since you got back in town? within a week of pushing it?

[Bitsyncmaster]

Do you roll it forward with the key in the ignition? I would assume so to stop the column from locking. If not, would "cycling the power" so to speak reset anything? It still stinks of inertia switch to me for some reason.

Now that's a good thought. When the key is turned on the idle motor eventually moves to full open (I think) if the key is turned that far. Maybe the idle motor gets stuck full open.

[jawn101]

Wow Jon you are sure getting all the tricky things I need to come over a fix.

Have you started the car since you got back in town? within a week of pushing it?

Lol! Yeah, I start and drive it as often as I can. It had run just the day before.

[jawn101]

I doubt anybody can come up with any relationship between hand-pushing on the infill panel, intermittent e-brake deployment and a non-start episode - and episode that later disappears.

While I know you did a thorough job on the wiring connectors and grounds when you first got the car, Jon, it's difficult to rule out something like a balky ignition switch, no? Or the connectors to it? Since the engine cranks and the f.pump is running have you tried checking the input voltage to the ign. coil during any of those episodes?

I'll put myself down as claiming that the rolling back and forth, in and of itself at least, is coincidental with the non-start, not a cause of it.

Always tricky to diagnose intermittents like this one but good luck anyway.

-Rich

Haven't had the chance to check voltages when this happens, no. Both times were at the worst possible moment and the focus was on getting up and out rather than real troubleshooting. In fact, I have yet to confirm that I can replicate the issue on purpose, maybe I will try that tomorrow.

[valdez]

I have nothing useful to post other then perhaps the
tire gaskets moved when pushing it?

[DavidProehl]

Haven't had the chance to check voltages when this happens, no. Both times were at the worst possible moment and the focus was on getting up and out rather than real troubleshooting. In fact, I have yet to confirm that I can replicate the issue on purpose, maybe I will try that tomorrow.

Definately start with replicating the issue. As you know, if it can't be replicated, you don't really know what is going on. My guess is that this is unrelated to rolling the car and is the loss of fuel pressure for some unknown reason.

[Jonathan]

Agree with David on trying to replicate.

Or at least noting down in a list exactly what the things you are doing when it has happened. Then compare that list to what isn't quite the same when you're driving, i.e. everything is powered up and running.

It sounds like a strange one to chase, but since it hasn't happened often, I'd also not worry yourself too much about figuring it out. For now. If it starts happening again, then you've got ideas to think of to spot what the problem is.

If it does happen again and you're not in a huge rush to get in and out of where you are, tackle it like the usual won't start stuff. Are you missing fuel, spark or air, or some combination of the three. The intermittent stuff is a PITA for any type of car and not just DMCs. Luckily you don't have the Generous Motors mechanic giving you a bill for $100 for him trying to figure out your "well, it was doing it when I made the appointment" problem :)

[rdarlington]

I promise you that it had nothing to do with the parking brake and rolling it. I do it all the time. It's something else. Cold start issue, hot start issue, electrical issue, but definitely not from rolling in neutral!

[Mike A]

I'm no mechanic, but I had a similar issue with my automatic. It turned out to be the Thermotime switch. The plastic around the connection was cracked. For some reason when I would push the car in or out of the garage it would cause a gap and not allow for full contact.

[DMCMW Dave]

You never mentioned it but when you go to roll it are you turning the ignition on (perhaps to unlock the steering ) without actually starting the engine?


Sent from phone

[jawn101]

You never mentioned it but when you go to roll it are you turning the ignition on (perhaps to unlock the steering ) without actually starting the engine?


Sent from phone

No actually, I hadn't bothered since there was no steering required. Just straight forward and back again... Should I have?

[DMCMW Dave]

No actually, I hadn't bothered since there was no steering required. Just straight forward and back again... Should I have?

No. I was thinking that if you did that, and had a leaky injector or two, you may have flooded the engine slightly.

There's nothing that pushing a turned-off car across the floor can do that could cause a starting issue.

[jawn101]

No. I was thinking that if you did that, and had a leaky injector or two, you may have flooded the engine slightly.

There's nothing that pushing a turned-off car across the floor can do that could cause a starting issue.

Well that clinches it, as far as I'm concerned... just a bizarre coincidence. I will try and replicate the issue over the next day or two but I'm guessing it won't happen.

Thanks Dave! :)

[jawn101]

Had a bit of a starting issue this morning as well too. Looks like it's actually just a common and transient cold-start issue. Not my first time at that rodeo, so I'll be checking out the usual suspects here when I get some time. The connector to the TTS looks like one of the pins may be backing out a little, that's where I'll be starting.

[jawn101]

So I confirmed just now that my issue is a pretty typical cold start problem. Couldn't get the car to start just now. Plug swap between CPR and CSV got me going right away, and then it started up again 5 minutes later with no issue (warm)

So that means my CSV is good at least. My TTS is only about a year old. I will test the resistance of it in a little while. Anything else I should check?

[David T]

So I confirmed just now that my issue is a pretty typical cold start problem. Couldn't get the car to start just now. Plug swap between CPR and CSV got me going right away, and then it started up again 5 minutes later with no issue (warm)

So that means my CSV is good at least. My TTS is only about a year old. I will test the resistance of it in a little while. Anything else I should check?

The main system that runs during a cold start is the CSV. Very rare there is a problem with the actual valve itself. Most of the time it is one of the following;
A bad TTS
A bad/dirty electrical connection
The plug was forced on wrong and burns out the TTS
A wiring problem
Anther system that runs during start-up is the ballast relay bypass. Not all that important but worth checking.
There are all of the vacuum hoses going to and from the CPR, vacuum leaks, and the vacuum advance system, all of which have an effect on starting cold.
Lastly, if the car is in need of a tune-up, besides having crummy gas mileage, you will have trouble starting cold.

[jawn101]

CSV obviously works, since the plug swap fired the car up. May be a backed out terminal in the blue plug though, not ruling that out. TTS is new and the connector was not forced on. No damage there. Engine is in perfect condition other than this issue that just cropped up suddenly. I will test the TTS electrically and will pull the CSV to see if it fires with the blue plug attached.

[jawn101]

OK, just had a moment at lunch to test some things out.

- Pulled the plug off the TTS and tested the pins. One read dead on 30 ohms, the other read 0.01. So the switch appears good.
- Pulled the plug off the CSV and inspected the pins. One is pushed back slightly so I tried my best to get it to re-seat and put the plug back on.
- Tried to start the car. It fired right up on the first crank. Except I accidentally hadn't reconnected the TTS. That switch is electrically odd since it gets ground from the body and the pins actually power the internal heater. Would a disconnected (open) TTS act the same as a connected and functioning yet open one?
- Reconnected the TTS. Car fired right up again
- Pulled the CSV and put it in a jar, cranked the motor. Gas in the jar, sputtering start as expected.

Wondering if that partially backed out pin on the CSV is to blame. Not really sure how to address that short of removing the connector and putting new pins on, which I understand are a little tough to find. Dave, do you guys sell or have these around?

Still wondering if the disconnected TTS works like a normally functioning yet cold one.

[alexwolf1216]

I did the exact same thing. I forgot to plug my TTS back in, and she purred like a kitten. Let it sit for 2~ hours, plugged it back in, started right up. Havent had a chance to start it again, but hopefully my parts come in this week and I can get it fired up. I am super curious if it will start right up like last time.

[jawn101]

I did the exact same thing. I forgot to plug my TTS back in, and she purred like a kitten. Let it sit for 2~ hours, plugged it back in, started right up. Havent had a chance to start it again, but hopefully my parts come in this week and I can get it fired up. I am super curious if it will start right up like last time.

Weird, huh? Last time this happened to me it was definitely a failed TTS. That was only about a year ago though. This time I'm really thinking it was that pushed out pin in the CSV, and I just need to find a reliable way of making sure that connection stays solid.