Starting question for the pros...

[Citizen]

Should be an easy one for the pros out there….

I have owned 3341 for about 10 years now. Except for one episode when it wouldn’t hot start, which turned out to be a bad accumulator, the old-girl has started right up first time, every time.

But today I went out to the garage to start and run it for a while, and this time it started but died in about 2 seconds, and would not restart. Acted like it had no fuel. So I put some starter fluid down the throat, and it started right up and ran fine for some 30 minutes. I shut it down, and it hot-started it right up again, just like always.

I let the car cool down, and got exactly the same routine when I tried to start it again. Ran for about 2 seconds, then quit, but started right up after a shot of ether, and then ran fine.

Each time I tried to start the car, I could hear the fuel pump run trying to prime for a few seconds, then stop, which I think is normal.

Question is, am I looking at a impending fuel pump problem? Or is this a loss of fuel rest-pressure? Doesn’t seem to be a hot-start problem at all. The fuel pump is the new DMCH combo unit, which I put in about 2 years ago, I think.

Any thoughts/advice? Thanks in advance.

Thomas

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[DMCMW Dave]

This one bites me once in a while (we often have cars sitting around with seriously low gas tanks), sounds like a dumb question but how much gas is in the tank?

The reason I ask I that the car will start with almost no fuel pressure due to the cold start valve, but it won't run that way. The fact that you got it to run for 30 minutes would tell me this isn't the problem but I thought I'd ask.

Sounds like the pump has a hard time starting, I'd check things like the RPM relay, the wiring at the pump, and wiring at the inertia switch. Also check the wiring connections on the ballast resistors and coil. Sounds unrelated but believe me it happens.

[Citizen]

This one bites me once in a while (we often have cars sitting around with seriously low gas tanks), sounds like a dumb question but how much gas is in the tank?

[SNIP]

Sounds like the pump has a hard time starting, I'd check things like the RPM relay, the wiring at the pump, and wiring at the inertia switch. Also check the wiring connections on the ballast resistors and coil. Sounds unrelated but believe me it happens.

It has slightly less than 1/2 tank of gas.

I didn't think to check the RPM relay, or the wiring, since the pump seemed ok. Funny you should mention the inertia switch, because I think it has been broken for a while now (I noticed it several months ago). Not broken as in the car won't start, broken as in the car keeps running in either position.

I'll also check all the fuel related wiring. This weekend is about done for, so this will have to wait until next weekend...I'll report back.

Thanks Dave.

Thomas

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[David T]

It has slightly less than 1/2 tank of gas.

I didn't think to check the RPM relay, or the wiring, since the pump seemed ok. Funny you should mention the inertia switch, because I think it has been broken for a while now (I noticed it several months ago). Not broken as in the car won't start, broken as in the car keeps running in either position.

I'll also check all the fuel related wiring. This weekend is about done for, so this will have to wait until next weekend...I'll report back.

Thanks Dave.

Thomas

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This can take some time to rule out things. Generally speaking, an intermittent problem is usually of an electrical nature but it can cause a fuel problem (the fuel pump doesn't run) or an ignition problem, no spark. The place to begin is to inspect some critical places in the electrical system like:
The fuseblock especially fuse #7
The inertia switch (make sure it has a splotch of white paint and is mounted on the footwell wall).
The plug and the connections right by the fuel pump
* The connectors and the terminals on the ballast resistor (this is the one I am betting on. The terminals on the ballast resistor are steel and they rust making a bad connection).

[Citizen]

This can take some time to rule out things. Generally speaking, an intermittent problem is usually of an electrical nature but it can cause a fuel problem (the fuel pump doesn't run) or an ignition problem, no spark. The place to begin is to inspect some critical places in the electrical system like:
The fuseblock especially fuse #7
The inertia switch (make sure it has a splotch of white paint and is mounted on the footwell wall).
The plug and the connections right by the fuel pump
* The connectors and the terminals on the ballast resistor (this is the one I am betting on. The terminals on the ballast resistor are steel and they rust making a bad connection).

Thank you Dave. I will check all those things. I didn't even think of the fuse box (I haven't cleaned my fuses in quite some time now, and I heard somewhere, probably here, that I need to clean them once per year).

T.

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[Ron]

Put your cold start valve in a clear container and see how it acts...

[David T]

Put your cold start valve in a clear container and see how it acts...

That's the one thing we can figure is working because he says the car will start and run (and then die). It is probably starting and running on the cold start valve. No need to waste time messing with that.

[Ron]

That's the one thing we can figure is working because he says the car will start and run (and then die). It is probably starting and running on the cold start valve. No need to waste time messing with that.

I with you... I was thinking maybe "about two seconds" wasn't long enough to give it a fighting chance, so to speak. IE clear out any cylinders that a leaky injector(s) may have flooded/fowled..., which, on the other hand, might be what it is starting on....and it does start when manually priming it.

Just food for thought.

[David T]

I have learned over many years of experience, the less you disturb during your trouble-shooing the better. All too often you can move or otherwise change something and it works but you really never know what you did that "fixed" it. And then the trouble reoccurs soon after again. By understanding the symptoms (the ones observed and the ones NOT observed!) we can rule out systems and some subsystems. With some further testing we try to eliminate things until we are left with the cause. Remember the basics, we need the mechanical to work (the basic piston, valves, and such) fuel and spark all working and at the correct time. In this case all of the starting systems seem to be functioning, it is what needs to work immediately after the starting cycle that things fail.

[Citizen]

... after I had a chance to get to it this weekend.

I inspected all fuses, and cleaned #1 & 7, although they looked ok. I inspected the fuel pump electrical wires/connections, and again all looked ok. Next I inspected the inertia switch. Yes on the white paint splotch, and mounted on the side of the footwell. However the switch was in the down position. So I moved the plunger up, and the engine started up fine, just like old times (which I thought the plunger should have been down).

So I’m thinking the inertia switch is bad. Not broken as in keeping the FP from running, but allowing it to keep running in either position.

Is [down = run] and [up = shutdown] normal operation for the inertia switch? Or is it the opposite?

Thomas

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