papasmurf

Purchased an early 85 a few months back as a project. The car like so many was likely neglected and has probably had it's fair share of shade tree porsche mechanics mess with it over the years. I purchased the car with it running (but very poorly and just barely) with what was likely some big vacuum leaks. The car was trailered home and has not been restarted since which was about late june until this past weekend. I changed the WP, timing and balance belts, drive belts, hoses, seals, etc. (everything you are generally told to do when attending to the frontside of the engine). I turned the car over without plugs slowly several times by hand to verify the timing (triple checked everything I did with paranoia) before putting it all back together. When we first started tearing into the car, the intake manifold was only finger tight at best which was probably a large part of the vacuum issue the car had. I have checked all the vacuum line routing and everything is hooked up correctly it seems. The car ran briefly 5-10 secs on starter fluid when we first started trying to get it started again but I cannot get it to start for more than 2-3 sec usually at best on it's own. The gas in the tank was bad so we drained it and flushed the fuel rail with clean gas. Plugs have spark, verified that injectors are firing, Fuel pump and FPR appear to be new...I hooked a gauge to the fuel rail and cranked the engine (did not jumper the DME for the pump) and it was showing fuel pressure in the low-mid 30's while cranking. I am at a bit of a loss of what to try next? I swapped a DME relay (there is tach bounce) just for kicks as I had another on hand but no dice. Crank/Reference sensors I believe were recently swapped out too. There is a wire that may have come loose somewhere along the way that appears to go to the coil that is fished through the pass side strut tower...Also a second plug on the headlight harness on that side that does not go to the headlight?

Van

You said you verified the injectors are firing - did you actually pull the fuel rail and verify by sight?

tempest411

What Van said+I'd verify that your AFM is working properly, especially the internal temp sender, and the temp sender on the block as well. I've read many an anecdote about these items failing and causing a complete shut-down as you're experiencing.

papasmurf

Yes, we pulled the injectors and fuel rail and cranked the car over momentarily as they "spit" into a towel...pattern was good. I have been scratching my head as to what the problem could be...something had to fail or become disconnected since purchase as it did run (poorly). I pulled the distributor and checked the timing of the cam against the fly wheel (cam mark lines up with TDC in inspection hole in flywheel) just to make sure nothing had slipped. My dad said the gas still did not seem up to snuff even after draining, flushing, and refilling the system (tank and flushed through fuel rail). I have a new fuel filter on the way in case the other one (which looks new) may already be clogged as there has been some debris in the fuel originally. Assuming the fuel tank is not ruined, is there a particular way to clean it out after draining (I plan on removing and cleaning the strainer too)?

Breakaway944

You flushed the tank and lines and verified injectors are firing correctly, therefore fuel is not your issue and cleaning the tank/changing fuel filter will do nothing (assuming you truly flushed/tested your fuel system) You verified spark at the spark plugs. You need four things for the engine to run 1)spark, you already verified. 2)spark, you already verified 3) compression 4) air - both in and out.
Since it ran on starter fluid I would question your testing of the fuel system. Early cars had steel gas tanks that rust internally and clog up the fuel system. Try starter fluid again, if car runs it IS your fuel system.
If injectors are firing right look into air flow, both in and out (exhaust). If air is getting in and out your last choice is compression. Since it ran before you probably have compression.
Again, when cars run on starter fluid it is a fuel problem 99% of the time. This is why the above posters suggested visually verifying injector operation. Perhaps you just bumped the engine and the injectors fired a couple times. That could be the gas that has leaked past the clog, if you keep cranking they would probably stop firing when the little bit of gas that passed the clog runs out. Pump several ounces into glass jars, not just a couple of cranks.

Breakaway944

R&R in the car repair world generally means "remove and replace" What did you mean by R&R?

Van

is your firing order correct? Could the distributor rotor be in the wrong position?

dzaprev

Soak the tips of the injectors in Berryman fuel injector cleaner. It frees them them up if there no operating fully.

papasmurf

that we did open the end of the fuel rail first after draining the tank and pump a fair amount of fuel into a can before we did the spray test on the injectors...from everything I can tell, there is fuel at the rail including including a fuel pressure test (~low 30's IRCC). I pulled the distributor when I checked the cam timing to the crank and made sure the rotor was not loose...it seems there is only one way it can attach to the cam with the screw, correct? When I drained the old fuel, I removed the two hoses on the tank (one was fuel pump I think and the other was the lowest one on the tank) and maybe a half gallon to gallon of nasty gas was drained. Four to five gallons of new gas was added and the car was started with the fuel rail open and a hose to catch any debris that was still in the system. There was some small rust particles in the old gas....my dad thought the new gas still seemed contaminated/bad when we were trouble shooting several days later after testing the fuel pressure. Thanks for your input too.

PerryB

Could you have a bad ignition switch? Does it supply power in the run position as well as when it activates the starter? I once wired an ignition switch incorrectly and it supplied power to the ignition only in the start position. The car would start, but as soon as I returned the key to the run position, it would die.

The Factory Manual has a step by step flowchart-like procedure for diagnosing no start conditions. Have you followed it?

Of course, you're not using an FAE brand speed or reference sensor, right?

papasmurf

Wasn't the ignition switch...somehow (even though I had labeled them beforehand) I had the firing order wrong. The car started several times and ran anywhere from 5-10 seconds at a time but still will not stay running. Eventually it got to where it would just turn over and not fire. I gave up at that point for the day as I was only able to mess with it about 5 min. or so after fixing the firing order issue.

Van

Glad you figured it out!

Tiger03447

Sounds like it might be time to check the fuel delivery/starting fluid again...

papasmurf

Did not get a chance to try starting the car again since last time (I only get 2-3 days/evenings to work on it a week) as I was busy replacing wheel bearings and putting the brakes back together. I did open the top of the fuel tank and remove the fuel level sending unit to look around and see how how good/bad the condition of the inner tank was in. Of course there is rust inside it...not sure if it is the worst ever but there is enough that I pulled the strainer (it was relatively clean) and drained all the fuel into a bucket. There was a very fine amount of rust in the bottom of the bucket...not a significant amount but the fuel was also tinted an amber color. It seems the only real fix is replacement or removing the tank and cleaning and resealing it which is going to be quite a chore.

Schwarz992C4S

Check the ignition relay?