Driving home from class tonight and the engine sputtered and died on me a few neighborhoods away from my home.


Here's what happened :
At a stoplight and noticed the idle speed was dropping suddenly and nearly died. I revved it up to keep it running, and tried to get the rest of the way home.

As I was driving the rest of the way home, the engine was surging and jerking whenever I stepped on the gas more than a small amount.

I pulled off the main road into a neighborhood and there the engine finally gave up and totally quit.

Trying to restart, the engine just turns over and over.

I checked the usual suspects and looked for anything obvious in the engine bay. Couldn't find anything. Once or twice the engine fired up for a short time, idled somewhat ok for 10 secs or so, but then dwindled off and died again.

A long time spent diagnosing and still nothing.

I switched the two main relays on the relay board with each other, and the engine again fired up for a short time, idled and revved up ok, then dwindled and died after 30 secs or so.

Trying to restart again, for a split second it sounds like it's trying to start as the engine turns over, a quick sputter but never fully fires.

That's where I'm left at now.

A few things I do know:
- It started raining today. I've been out and about with no rain tray on, not a good idea but I did it. It was running around fine all day with no symptoms until this.
- Been running perfectly fine for the 400+ miles now since I installed the engine.

This hiccup came suddenly from nowhere.

Engine is a 1.7 djet from a '72....

Could something electrical be shorting out from the water, causing this intermittent and choppy running? I've looked at everything and there's nothing I can see that's a culprit. The only thing I noticed was the switching of the two relays helped it fire shortly.

Is it maybe fuel? I don't know the symptoms of fuel starvation. The pump is pumping and appears to be working fine. Clogged filter? The filter only has 400 miles on it.


Any help MUCH appreciated... I'm going back in the morning to try and get it home.

Is your gas gage accurate? Sounds like fuel starvation symptoms. Happened to me once and my gage was showing 1/8 tank left. Hey , the gage is over 30 years old.
Tom

Thanks. I was thinking that too but I put gas in it earlier today and the tank is showing 1/4 full. I haven't driven near enough for it to be empty though.
That's happened to me before though.... never suspected an empty tank.

Check the points, and the point plate ground strap. The Cap'n

And while you have the cap off, check for condensation in the cap. Water + heat = steam and that can get in the cap, shorting the spark to ground. WD-40 and a clean rag can fix that .
Tom

Thanks.... shoulda mentioned it's a pertronix unit inside.

The condensation thing still applies though right?

Go get a can of starting fluid and see if it fires up.

Can you hear the fuel pump running?

A kink in the fuel lines maybe? Check your fuel pressure. You didnt make the mistake of 'upgrading ' to extra long fuel lines at the tank did you?

No, lines up front under the tank are to the right length as far as I know. I did them a while ago - No problems at all for 4000+ miles (on a previous engine)from the hoses up front. Could they sudden kink out of nowhere?

I can hear the pump running when I turn the key on. I looked as best I could at the fuel pump and lines going to it, nothing seemed kinked.

Forgive my ignorance, where do you spray starting fluid on a FI car?



One thing I didn't mention - I've run the tank down to reserve a few times recently. In fact I run it down low pretty often. I never had any problems with my previous carbed engine, but maybe with the new FI engine the FI fuel filter its getting clogged from whatever debris on the bottom of the tank??

Take off the air cleaner and spray into the throttle body. Doesn't take much. Crank the engine at the same time.

I'm no expert but water shorting to ground somewhere seems reasonable. Also my car died simularly not long ago. Engine pretty much cut out real quick. Fuel pump gone. You could still hear it run though. That was my second pump. I'm on my fourth now.

May be nothing to do with the rain... just coincidence. Mine did something like that when my MPS failed, IIRC (20 years ago). Try sucking on the hose to see if it holds a vacuum.

Jim

There was a thread a while back about a fuse that went bad. Given that you got a little joy when you fiddled with the relays maybe your fuse is giving you problems? Fits with the sudden onset. Try a volt meter across it terminal to terminal. It should be 0v - if you get some voltage across it you may have your culprit.

Hey Hammy,

Check the fuel filter. It sounds llike the car wants to fire AFTER it sits for a few.

If the filter is clogged it will starve the engine. When it sits, some of the particulate that is clogging it moves away to let fuel by. it will restart for a bit and all the particulate collects again and reclogs the filter, starting the cycle over.

I totally agree with toon

the same thing happened to me with my carbed engine. turns out i had some rust in the tank that got into the fuel pump and jammed it (yeah, i jammed a facet pump)

the fact that you said you just filled it up tells me that you have gunk in the tank thats getting stirred up by adding new gas, that's what did it to me

it's also possible that running the tank down sucked some junk off the bottom of the tank into the fuel lines and clogged it

pat

Mine did this exact behavior and it was the braided ground strap between the advance plates in the dizzy that broke.

Funny coincidence... I was also driving home in the rain, the motor popped, started running like crap, I pulled into a parking lot, and it died and wouldn't fire again. I'm also running Pertronix.

Have you checked the spark? Pull a plug wire, put a plug in it, ground it to the case, crank, and watch the spark.... It needs to be bright and strong. When mine was having this trouble, the spark was intermittent weak and yellow. After running a temporary ground wire from the top advance plate to the outside of the dizzy I got a fat blue spark and it started right up and ran perfect.

(Beware, if you keep cranking and start smelling gas like you think it might be flooded... Don't keep cranking until you verify strong spark or you could get a nasty backfire that might even blow your muffler open. Don't ask how I know.)

Just walked down to get the car and she started right up ... I got it back home now.

I'm going to put in a new fuel filter and go over all the electrical contacts...

that was frustrating.

My car did a thing where it died everytime I turned right. Turned out to be a clogged filter.

Rust for me. See if you still have the mesh filter in the tank. Its the one that sits inside the baffle thing. The mesh filter thing is suppose to stop debris from coming from the tank and into the system.

When I had the FI, the fuel pressure was very erratic. 2 years later with carbs, like everyone else has said. Now have a filter before and after the pump.

I'm still thinking something electrical since you should be able to push / pull some fuel through the system.

Like advise to me in the past, check spark and fuel.

Check the coil wire or around the distributor. Wife had a car that used to have a similar issue what happened was that the boot around the coil wire on the dizzy had a crack that you couldn't see, but if you had someone else crank while you were looking under the hood, you could see the arc across the wire to the dizzy. (obviously easier to see when it was dark) It would do exactly what yours is doing where if it sits for a while ie: a day it would dry out enough to run. ( cuz there's no water to conduct the arc from the wire. Also had similar issue with my 81 Mercedes. The wires would heat up and expand and then arc to the valve covers. solved this by getting some fuel line a little bigger and split it and wrapped it around each plug wire. Just a thought??

1

I had the same problem on my old 911SC. The car ran fantastic on dry days but H2O in the engine area from washing the car or driving in the rain would cause a short with the spark shorting out through cracked ignition wires. I would get stranded in the rain and have the car towed to the shop for repairs. The rain would stop, car would dry and mechanic could not duplicate the problem. I finally figured it was the water in the engine area causing the problem. I tracked down the short by taking a spray bottle and setting it to mist. Once it was dark I misted the engine and looked for the arc.

Thanks. That's something I can check for too.

Though the possibly of this being the problem might be eliminated due to what happened today:

After I got the car home, I let it sit for an hour or so and then decided to chance it and go for a quick drive to the parts store and to see if everything was working ok. No rain today and the engine compartment was dry. It ran normally but then suddenly stumbled again and died while sitting in traffic. Luckily it restarted with some cranking, and I quickly got it back home as fast as possible.

Since then I have put in the new fuel filter and cleaned/sanded the relays on the relay board. Haven't test driven it yet though.

I would totally check those ignition wires!!! They could just have a crack or maybe weakened and are arcing to the block??