Ran the fuel tank dry and now the car won't start

[Hezath]

Last time I drove my car (about a week ago) it was pretty low on fuel and I was intending to fill it up first thing next time I drove it. My driveway has a slight downhill gradient and the front is a bit down the hill in relation to the rear of the car. Not sure where the pickup in the fuel tank is - I've never had it apart.

Anyway, just went to start it up for a drive. Turned the ignition on and the fuel pump started up and made the normal humming sound apart from a moment where it sounded a bit like it was breathing bubbles - I didn't think much of it. I cranked the motor over and it fired for a fraction of a second and then I couldn't get it to fire again. It's not uncommon for me to have a second or third go at starting it and fiddling with the hand throttle to get it to idle, while trying to avoid starting it with the throttle cracked open lol.

It just kept on cranking and didn't even have a hint of kicking/firing after that. I got out a Jerry can I had lying around and probably put 4-5L (about a gallon) into the tank, I sat there for half a minute with the fuel pump going to see if that would make any difference etc before I tried again.

Just cranks over and nothing happens at all - does the system need to be manually primed or something tricky like that? What are some things I can look at to ensure that the fuel is actually reaching the points it should be at? I'm not actually sure that it has spark but it seems likely that the fuel situation has caused this.

It's a standard (as far as I'm aware) SC 3.0L engine with K-Jetronic and an MSD box.

And I'm not sure if it's worth noting, but if I have the key in the ignition on position and push it towards the starting position, the fuel pump noise stops (sounds like it completely turns off) and I'm not sure if I can hear it going or not while the motor is cranking - there are too many other noises going on.

I really didn't expect it to be a problem! Not sure how much juice was actually in the tank but it was still driving smoothly until I turned it off last week.

[tazzieman]

Originally Posted by Hezath

It's not uncommon for me to have a second or third go at starting it and fiddling with the hand throttle to get it to idle,

It's a standard (as far as I'm aware) SC 3.0L engine with K-Jetronic and an MSD box.

.

Hand throttle on an SC engine? What year is your car?

Edit : I see you have a '75.
Do the injectors squeal with the ignition on when you lift the air sensor plate for a second?

Other ideas here 1976 911S No Start Flooded cold start issue 911Sc

If it was running fine before , I'm sure it will run fine again soon as long as you don't start fiddling e.g. with the mixture !
Have you done anything else recently that may have affected the CIS system?

[twistoffat]

You might have got some dirt from the tank into your fuel lines after running the tank so low. Change out the fuel filter it may be clogged

[JJ 911SC]

You may have suck some bottom crap and plug the filter.

To confirm, have some one crank the car while you spray some "quick start" in the intake, if it try to start you definitely got a gas (Petrol) starvation.

P.S. I guess tazzieman & twistoffat did not get caught in the "Down for Maintenance" time warp

[tazzieman]

Originally Posted by JJ 911SC

:
P.S. I guess tazzieman & twistoffat did not get caught in the "Down for Maintenance" time warp

Did! But unlike the usual downtime , it fired up again quite quickly! Always frustrating as it happens when I'm comfortably ensconced after dinnertime!

[clutch-monkey]

i was told by a local mechanic that it does not take much to clog the fuel pumps on these - i.e. can happen running the tank dry and some muck getting in.
if your pump is having trouble that might be the case? would be the first thing to check i think, as per JJ's post!

[JJ 911SC]

Originally Posted by tazzieman

Did! But unlike the usual downtime , it fired up again quite quickly! Always frustrating as it happens when I'm comfortably ensconced after dinnertime!

Here it happened before breakfast, read the paper a bit more, submit and where do these postings come from...

I guess for twistoffat its in the afternoon

[Hezath]

I haven't even looked at where the fuel filter is on this car yet! But that sounds like a plausable cause and remedy.

Thanks for the help guys, I'll keep the thread updated with how I go.

[clutch-monkey]

if it's like mine - fuel filter will be in your engine bay, easy enough to find.
fuel pump is right behind the fuel tank, under the car. four bolts will undo the skidplate thingo that's hiding it:


after i put my fuel tank back in i had similar issue, but it was a ground wire i think. still, fuel pump is easy enough to replace yourself if it is buggered!

[Hezath]

Yep looked on the left hand side of the engine bay and found two canisters, I'm guessing one of them is the fuel filter, will inspect a bit more thoroughly soon

Thanks for the location of the pump too

[porwolf]

Check out the tank screen filter also. That is the first line of defense against fuel dirt. And while you are having it out check for solid fuel gunk right above the threads. You can get it out, if necessary, with carburator cleaner small rags and a stiff wire bent L-shape at the end. Also check with a wire for clear passage from threre through into the tank outlet to the fuel pump.

Pelican Parts - Product Information: 911-201-141-00-OEM

[porwolf]

Originally Posted by Hezath

Yep looked on the left hand side of the engine bay and found two canisters, I'm guessing one of them is the fuel filter, will inspect a bit more thoroughly soon

Thanks for the location of the pump too

Check for fuel filter for you car on Pelican Parts here. They give you good graphics where parts are located also.

[Porsche Head]

I ran my tank dry while doing a winter start, burnt out the fuel pump. Put in Walbro and some gas and it fired up.

Cliff

[Hezath]

Did the fuel pump just stop making noise? Or did it sound like it was working but stopped pumping?

[Hezath]

Well I put another 15L in the tank and confirmed that the fuel pump worked and filter wasn't blocked by disconnecting the outlet of the filter it and switching the ignition on, the it pumps heaps through that filter no problem.

Really don't know what the problem is now. I don't have a second person to help me check for spark

[RoninLB]

Originally Posted by Hezath

it pumps heaps through that filter no problem.

Really don't know what the problem is now.

Icheck for spark

Change the tank screen anyway if your car has over 200,000 clicks on it.
It currently has one foot in the grave and the other on a banana peel



My 1977 CIS intake has a flapper valve that starts the pump and pushes fuel thru the injectors and into the cylinders
-Key turned to "run"
-Lift valve
-Listen in a quiet area for 3-5 seconds for fuel flow thru injectors
-Lift the valve too long and you flood the cylinders


Spark... get a starter jumper gizmo or use any wire [cheap jumper buttons and clips suck]
-Turn off all electrics in the car
-Make sure you have a good charge so you don't create a low voltage issue that may damage your ignition
-turn key to "run"
-rig your spark test rig
- jump starter and watch lightning

If you need entertainment install a 20 amp waterproof marine momentary start button switch in the engine compartment permanently connected to the starter. Use 12 gage wire. I use red for both legs. For $15us it's the cat's ass in cool when you're going thru bs trouble shooting

[JJ 911SC]

Originally Posted by Hezath

... Really don't know what the problem is now. I don't have a second person to help me check for spark

Maybe the running out of fuel is just coincidental so you as RoninLB, you need to know if you got spark or not.

For the second person, anybody will do; wife, kid, neighbor... All they will do is turn the key on your command, so they don't even have to be tall enough to reach the pedals

[Paulporsche]

You may simply need to prime the system by raising the plate in the mixture control unit w/ the key in the "on" position. Do this only for about 3-4 sec so the engine doesn't flood.

[Hezath]

This is just raising that pivotting upside-down plate at the back of the airbox (part of the CIS system)? I can easily try that!

[Hezath]

Awesome, primed it doing exactly what you suggested Paulporsche and she fired into life. What a refreshing note!!!

Thanks for all the help guys