993 Won't Start

[J4yDubs]

My 993 won't start now. It was running in the Fall. The starter cranks the engine, but it doesn't ignite. I changed the DME relay, same problem. I squirted a little bit of starter fluid in the air box and it tried to start, but doesn't. I don't want to continue doing that so I stopped. I'm thinking fuel pump since it ignited briefly with the starter fluid, but want to check for anything else to look for. Any other tests to try?

The fuel is a little old, but I have put Sta-bil in the tank. I'd expect it run rough with bad fuel, not start at all, but I could be wrong.

I'm not a mechanic, but can do enough to get in trouble. Probably going to have to have it flat bedded to a shop.

[jac911]

You're on the right track. It takes 3 things to make the engine run: compression, spark and fuel.

Compression is usually out of the picture on a condition like you describe. The engine wants to run with some starting fluid sprayed into the air intake so you have spark. That leaves fuel. That's where I'd start the investigation.

There are many references and threads on fuel system troubleshooting the 993 available. It could be anything from a bad fuel pump, a clogged fuel line or fuel filter or even out of fuel (don't laugh....seen that one before when helping former students). With a little time and patience you should be able to determine the cause of the fuel issue. The Beatles had a phrase to remember here..."with a little help from my friends." Keep them in mind as well.

JC 96 TT

[Synapse120]

Could also be the immobilizer, i believe there is a switch behind the clutch that has to be depressed to deactivate the immobilizer. This switch could have gone bad.
Focus 9 has a pump prime solid state DME relay that can be used with 95 NA 993 (non pump prime for other year 993 and except turbos). I have these in my 944 and 951, but have yet to put one in my 95 993, but they let you hear the fuel pump run for for a couple seconds if you put the key in the on position but don’t crank it over. They also have models with diagnostic lights.

[07turbeaux]

If you changed the plugs in the fall, I can help. For two years my 993 would not start when the temp outside was over 85F.
It started after the car was tuned at highly thought of shop.
Best of luck

[911-Purist]

I'm thinking fuel pump...

Easy enough to check. Connect a fuel pressure gauge to the outlet of the left fuel rail (driver's side) and you should see about 3 bar or 44 psi based on memory. The cap that screws onto the outlet on the fuel rail is supposed to be a one-time use cap, so you might want to order one. P.N.: 993 110 218 01.

Can you hear the pump?

[911-Purist]

The fuel is a little old, but I have put Sta-bil in the tank. I'd expect it run rough with bad fuel, not start at all, but I could be wrong.

For your info, I store a motorcycle overseas and during Covid BS, I didn't get over to use it. Two years and ten months later (July 2019 to May 2022), it started as if it had run the day before after getting a battery boost. It gets Sta-Bil every year prior to storage.

[J4yDubs]

Thanks everyone! I'll give the suggestions a try.

[J4yDubs]

I saw an article on Pelican Parts, so I did a couple of the tests. I removed the DME relay and checked for voltage on 30. Good. Turned on ignition and checked voltage on 86. Good. Jumped 30 and 87b, I hear a faint thump, but don't hear the fuel pump running.

The article also said "Check for ground at terminal 85 (yellow arrow), if there is no ground then you should check the ground connection on the number one intake runner. ". When I check for ground on 85, that check fails. I'm not sure what the "number one intake runner" is? Tested ground with ignition on and off.

Also, I bought the Focus 9 SS DME with lights. When I turn the ignition on, I get lights on Ignition SW and Fuel Inj. Power, but no light on Ctl. Fuel Pump or Fuel Pump.

[911-Purist]

Do you have a full set of wiring diagrams for your car?

A quick test, run power directly to the fuel pump. If it works, you'll know. If not, you have an issue upstream.

[J4yDubs]

Just a quick update. I finally had time to get it up on stands and change out the fuel pump. What a PITA, but got the new one in. She starts and run perfectly now so my guess at the fuel pump was correct. Thank God. Old pump has a electrical burn next to one of the terminals.

Now my fuel gauge is showing empty. I know there's at least half a tank, probably more. I'm thinking it must have gotten stuck when I had the front end up in the air. Once it stops raining I'll have to take it for a quick drive and see if it starts working. If not, that will be my next project...