Stored 72T will not start. HELP! Fuel Pump?

[OkieRon]

72T has been sitting for 15 years.
-Cleaned out gas Tank
-Replaced Plugs
-Cleaned fuse connections at back
-New Fuel Filter
-9 quarts of Oil
-Hand cranked a few times to get oil into the cylinders

Went to try and start it last night and it would not get any fuel (no fuel coming out of bottom of fuel filter)

I have read on this forum that when you turn on electrics you should hear the CD box whine and the fuel pump whirring. I hear the CD box, but no FP whirring. I put a little gas down the stacks and engine sputters but that is it.
If I remember correctly, the fuel pump is located at the back on the drivers side of the tranny. I have the cold start unhooked/unplugged and the dash oil light beeps when electrics are turned on. I don't think either of these should affect startup. I am going to check the fuel pump tonight- ANY IDEAS on what I should do?? Any help would be appreciated. Thanks Pelicans!

[RickM]

If the gas tak is rusted inside it will continue to clog your filter. It may be very hard to clean everything out. Perhaps a clean and internal restore coating or a good used tank.

You'll need to verify flow before and after the fuel pump. Don't some pumps have a screen for larger debri as well? This may be the case for the tank as well.

[competentone]

Was there old "gas" in the fuel tank when you cleaned it out? What did the inside of the tank and fuel filter look like?

You say it was "stored" for 15 years--was it prepared for storage or was it just "parked" with the fuel tank, pump, lines and carbs still full of fuel? If that's the case, the old fuel is likely to have turned to a varnish like residue and will probably require substantial disassembly of the fuel system to clean.

[OkieRon]

Thanks Oh Compententone. Yes it was parked. I plan on pulling the fuel pump and probably having it rebuilt.

[rickeolis]

Given what you said about the filter not showing fuel, it's the thing to tackle first.

Put the back of the car on jack stands and follow the fuel lines to the pump (wherever it may be, but will be along this route), then remove it and bench test it.

The jets in the carbs may be clogged up with varnish like COMP said, but take it one step at a time, and you'll be driving it in no time!

If you get the fuel pump working and are able to get the engine going, then run chemical line cleaners in the tank as suggested by your local parts stores, and you should be in business again soon.

[RickM]

15 years of hardening means some seriously tough varnish to disolve without destroying other components.

The step by step advice is good. Like any troubleshooting it's a logical process of elimination. Stop one....Fuel tank. Just my 2 cents.

[Grady Clay]

Ron,

OUCH, it will take some extensive care to put your 911 back in service without damaging itself. You need to start from scratch.


Disconnect the ignition box and fuel pump. Drain the oil, check the sump, and refill with fresh oil. Replace the oil filter. You might want to rinse out the oil tank with Stoddard solvent while return the suction hose to the engine off to a drain pan. You don’t want any rust flakes from the inside of the oil tank pumped to your bearings.

First, pull the plugs and intake valve covers and inspect for any sign of rust. If none, lube everything in sight. Remove the inboard side cover of the MFI mechanical pump. Be prepared to catch about 500 mL of oil. Inspect for any rust and reinstall cover. Refill pump with fresh oil through the overflow hose. Does the engine now turn over by hand? Do more than two complete revolutions by hand each time. If it feels OK after several tests, crank on the starter for a few (5) seconds. Wait a few minutes and repeat, periodically lubing the cylinders.

Inspect and lube the distributor advance mechanism and cam. Separately test the ignition for proper spark and static ignition timing.

Check the MFI pump timing and belt condition.

Drain any fuel from the tank and inspect the bottom of the tank and pick-up screen for rust or contaminates. Clean as necessary. Fill the tank 1/3 full with the highest octane fuel you can find (the lube oil reduces octane) and some “fuel cleaner.” Reconnect the fuel pump and test the fuel system for both fuel pressure and fuel flow back through the gas filler. Inspect the functioning of the cold start solenoid (must squirt fuel when on and not leak fuel when off.) Crank more with the ignition off but the fuel system on (except cold start). This will purge the fuel pipes to the injectors. You should be able to smell fuel pumped out of the sparkplug holes. Wait for a day or more so the fuel additive can work on the injection pump pistons and nozzles. Repeat until you are convinced the MFI is getting fuel to all cylinders via the nozzles.

After you are convinced everything turns over smoothly, you have oil pressure while cranking, and the MFI is working, then install new sparkplugs. I would choose a relatively hot BP6ES for this testing. If they fowl from the excess lube, pull them out and clean with “electric clean.”

When first starting, keep the engine below 2000 RPM and only run for 15 seconds or so. Wait for 10 minutes and repeat a couple of times.

Insure everything is OK and drive with some high throttle to get full cylinder pressure and consequent ring seating. Do this for only a few minutes (5-10) and then park it for a half hour or so. Repeat several times.

As you become increasingly confident everything is working properly, extend your tests. If anything fails or stops working properly, STOP IMMEDIATELY. I wouldn’t be surprised at chain tensioner failure. This procedure may not rescue your 911 from 15 years of non-driving but I think it is the best chance.


If it were my 911T, I would do a maintenance rebuild on everything. I don’t want to break anything and like to have confidence in the 911.

Best,
Grady

[Jay Auskin]

There's a fairly fine mesh screen in the tank fitting that supplies the pump. You'll want to take this out and clean it. It can fill up with lots-o-crud. 15 year old fuel is nasty. I vote for removing all fuel related components, and cleaning/checking. I just finished rebuilding my '72T engine. While it was out, I replaced all fuel hoses, and cleaned out all fittings. Not to mention, I ceaned teh pump, checked it, and had the injectors ultrasonically cleaned. Fuel can varnish something severe. Most fuel system cleaners won't do the trick if it's been this long.

[OkieRon]

Thanks Grady,

I pulled the gas tank and had it etched. I am not getting any fuel to the filter. My guess is the line from the pump or the pump itself is clogged from varnish. I do not hear any whizzing from the fuel pump so that will be the first thing I check. I will give you an update. Thanks All!

[OkieRon]

Thanks Jay,

BTW, does your 72 have a seperate reserve oil tank that needs to be emptied. I haven't found documentation as everything I read says "empty reserve tank as well - except 72.?"

[Tim Walsh]

hmm.. if you're asking about the "reserve" tank you might want do lots of searching here. I belive the reserve tank you're refering to is the oil tank. There isn't an oil pan per say on these cars, it's a dry sumped system where a seperate pump pulls all the oil out of the bottom of the engine and puts it in the oil tank so there's always a good supply of oil no matter what.

BTW welcome to the board, 72's are almost my favorite year (behind 73's ). Got any pics?

[OkieRon]

Tim,

I am putting the fuel pump back together as we speak and dog gonit if I forgot which way the top sits in relation to the electrical plug in. Is there a schematic on the site for the FP??

[thastings]

Ah!!!!!!!!!!!!!!!
The smell of 15 yr old gas opens the sinus, as I just learned on my 72T that was sitting for 12 yrs.

The fuel pump is under the front passanger floor board, not in the rear. You should hear it when the key is on. I had to remove it to get the hoses off. After cleaning it, the return line check valve was still sticking open (which I learned the hard way). If the car starts but does not seem to produce HP then check the gas filler tube to hear if there is gas flowing into the tank. If so, clamp the return line from the gas pump and see if it runs better.
Grady is right. Clean the tank, replace the filter (don't even consider using it because it IS bad, even if your positive it still good). Replace the fuel hoses unless you get good flow in each section of the system.

I removed the MFI pump and removed the side plates to check the interior injector pistons. One was seized, and sitting in 2 gallons of WD-40 (I now have a lifetime supply) for a week, it was still seized. Time to call Uncle Zak.

It takes about 15+ seconds to pump the fuel back into the system when you start it the first time after draining and replacing parts.

Check the ignition points to make sure they are still at the right gap. My points were still good but had closed up?????????? I ended up putting a MSD which helped to lean it up. It helped but the old Permatune unit did a decent job. Don't go to this just to solve a rich fuel problem.

Replace the brakeline flexible hoses at the calibers. Mine were bad and I thought I was having fuel pressure problems, when it was the brakes locking up the left rear brake and not releasing with the pedal. I found this one when I accidently put my hand on the left wheel while standing on the roadside cussing at the @#!% fuel system.

I am just now starting to drive it on short runs in hopes that a lot of the old buildup inside the injectors, valves, heads, etc., will start burning off.

Good luck, it may trke a few weeks of little changes to get it right, but the MFI runs great when right.

Terry

[RickM]

Originally posted by Jay Auskalnis
Fuel can varnish something severe. Most fuel system cleaners won't do the trick if it's been this long.

If you need to clean the varnish off various parts you can use a product called Gum Cutter. Be careful as it will remove CAD plating as well.

I think Easy Off Oven cleaner works too

[power]

The fuel pump on my 72 mfi cars is drivers side rear (in front of leftside rear wheel well). I have seen two fuel pumps seized from rust after sitting for long storages.

[Early_S_Man]

Ron,

Hopefully ... the outlet fitting and fine bronze screen were removed during the cleaning!

Since rust in the tank has become an issue, I believe the hard fuel line through the tunnel will need to be replaced. It could possibly be blown out with compressed air, but I believe rust will continue to be present and will continue to cause problems.

The fuel pump can be disassembled and cleaned, as one Pelican did ... and posted pics a couple of years ago ...