1977 911 with a 3.2. Has been sitting, won't start, let's discuss

[Porschenutt]

Hello,

Just bought a 77 911 coupe that has a 3.2 in it. When I went to look at it owner was certain it would run. While negotiating a price he was asking a good bit more that I offered and said come back on the weekend and it will run. He told me if it runs I want X amount more...it didn't run, but the engine spins.

I bought the car much closer to my original offer price.

More details I've uncovered:

Car sat on an aluminum trailer for about a year (according to previous owner).

Car was repainted (not a good paint job).

Previous owner said sunroof leaked because they did the seal wrong at paint shop.

He believes motronic got wet.

He bought a new motronic, it came with the car. When he told me to come back, his plan was to plug in motronic and I guess assumed it would then start.

I now have the car at my house and I'm about to spend some time trying to get her to run. Talk me through some suggestions.

Because it sat, I plan to drain fuel and oil and replace with new fluids.

Buy plugs and wires.

Thoughts on what else I should do or check.

I have two motronic now, one supposedly tested and functional, the other he believes got wet. Is there a place to test them?

Any help on things to check and what else I should do would be great.

Thanks

[Porschenutt]

[larrym]

1. check if the injectors are working and squirting fuel

- after you confirm you do have fuel pressure

it not uncommon for them to "stick" or varnish in long-sit situation like this

couple yrs ago i posted a long collection of diagnostics links - 3.2 starts dies immediately - all tests good

you already checked this one, eh? Porsche 911 Engine Starting Troubleshooting | 911 (1965-89) - 930 Turbo (1975-89) | Pelican Parts DIY Maintenance Article

[steely]

Does it even crank? (I am assuming it must if owner thought DME)
If it does, I would shotgun and stick the original DME back in to see if it turns on.
Key on and feel if ICV is buzzing, then go from there.

Or if you want to go conservative, send one board out or see if a friend will let you test one in his car.

While you're waiting check the wiring to the DME and the relay to make sure it's in good shape & wired as expected.

That's all I can think of, there will be more. (opps - Larry gave a ton already)

Please let us know what you do.

Good idea on the fuel etc.
Congrats! That car looks great!

[jamesjedi]

If crank and no start - Check for fuel, spark and power.

A PO may have understated the sitting time.

I am not certain how long it takes for fuel to harden. Fuel hardens and can clog the injectors. Same with fuel pump. The injectors have a high probability of needing removal and cleaned. There are a few recommended places to do this reasonably.

You must replace the injector O rings when reinstalled, and lube the rings.

Test for spark.

[cabmandone]

DME Relay first. Make sure you have a known good DME Relay installed.
Power your fuel pump and make sure it's working. The fuel pump will not run when you turn the key on, it will pump while cranking. Once you're sure the fuel pump works move to spark. Go buy a plug, pull a plug wire and verify spark. If you have spark, move to a "noid" test for the injectors. If you're not getting spark I'd verify the speed and reference sensor connections as well as that each lead from the harness is connected to the right sensor. When I bought my donor car, someone had the wires from the speed and reference going to the wrong plug on the car harness.

I'd make sure the ground strap at the transmission is connected under the car. I'd also verify the grounds on the intake runner.

[Rodsrsr]

Lots of suggestions but do the obvious first.... Does the car have spark? Pull a spark plug wire at the plug end, stick a screwdriver in it and hold it close to ground while cranking to check for spark. Don't waste your time doing anything else until you determine this. If no spark than you can determine why.

[Flat6pac]

You’re depending on some other person ability to install a Carrera motor in an early chassis.
I would check for the correct connecting with power where it’s tapped in to the chassis harnesses.
A blown fuse or a DME relay can make you chase in circles.
I had one tapped into the backup light fuse The backup lights blew the fuse and the car wouldn’t start.
Send the questionable DME to CHIPS.
Bruce

[Porschenutt]

Ok, so a few updates. Haven’t had too much time on the car...promised my kids Justice League...

Anyway, got back from movie and started poking around. First, I found a file with literally $20-30K spent on this car...so that seems promising.

There is a receipt from the shop that did the 3.2 install. Going to see if they are still in biz and call tomorrow.

So far, I have found two blown fuses inside the front truck fuse panel and a missing fuse in the engine bay (where there should be three fuses on the drivers side of engine).

Going to replace all of them once I figure out values and report back what each one was for.

The main car ground is horrible, I will replace it.

I found a braided metal ground again on drivers side of engine bay that is not hooked up.

[Porschenutt]

More news, #6 fuel pump fuse was blown...or at least it fell apart in my hand when I checked it...possibly a good sign...

[Porschenutt]

[Porschenutt]

Looking at the above fuse panel. What does the fuse on top do? It’s clearly missing. Also the fuse underneath looks and feels as though it’s barely making contact

[cabmandone]

Since it doesn't have a wire coming out the back side.... not much.

[Porschenutt]

Originally Posted by cabmando

Since it doesn't have a wire coming out the back side.... not much.

Yes but there does seem to be some wires on one end, guess it’s just used to join them together?

How about the second fuse? It’s loose

[Porschenutt]

Ok, found those three via search. Seems they have nothing at all to do with my issues.

Fuel pump fuse is promising.

[Porschenutt]

[Porschenutt]

If you look close in the above pic, you will see a braided ground wire...it’s not hooked up, any guess on what that’s for?

[cabmandone]

I'm looking closely and I can see your CHT wire isn't connected or at least not from what I'm seeing. Won't effect starting so much but it will make it run like hell once started. Probably increase crank times too. Since you know where the fuse is for the fuel pump, jumper to the bottom wire from a hot source and verify it's working. Your fuel pump could be seized which might blow that fuse.

BTW, I meant to tell you earlier that panel has nothing to do with your problem.

[Rodsrsr]

You're making this way too complicated... Its very straightforward. An engine basically needs three things to start. Spark, fuel and compression. Do you have spark YES or NO?
If yes move to fuel. If no spark, than there are additional tests to determine WHY the engines not getting spark. By not following this simple order you will waste time on systems/components that will reveal themselves to be good just by the fact that the car produces spark.

[Porschenutt]

Originally Posted by Rodsrsr

You're making this way too complicated... Its very straightforward. An engine basically needs three things to start. Spark, fuel and compression. Do you have spark YES or NO?
If yes move to fuel. If no spark, than there are additional tests to determine WHY the engines not getting spark. By not following this simple order you will waste time on systems/components that will reveal themselves to be good just by the fact that the car produces spark.

OK, I have to go buy a battery in the morning. I'll test for spark and report back!