Noob: 77 911S won't start. Help appreciated.

[modelyear1983]

Hi all, I'm a longtime admirer of the 911 currently diving into a simple (it would seem) mechanical project for a friend. I know my way around vintage air-cooled Volkswagens, so everything looks fairly similar out back, but I'll admit I'm in a bit over my head.

A friend's son recently passed away, leaving behind a fairly tidy 77 911s non-sunroof model. The car has been sitting for the past three years in his garage as his son's health continued to deteriorate. I volunteered to get the car running and cleaned up for him so he could sell it (and damn do I wish I could afford it!).

The car was started and run occasionally in the past three years. Fuel stabilizer was added to the tank last year. The car ran as recently as last year, but poorly. Receipts going back to the early 80s show that both the motor and transmission have been rebuilt.

Right now the car turns over but won't start. Last Sunday I spent some time familiarizing myself with the car. Today was a bit more productive. I started by pulling all the plugs, which were visibly wet with fuel from trying to start the car last Sunday and probably flooding it. I did note that the plug on cylinder 1 was noticeably drier.

I dried the plugs, shot them with some contact cleaner/enhancer and reinstalled them. I left out the plug for cylinder 1 and checked for spark as per the Bentley Bible. Spark is good and blue.

I slowly moved the distributor's timing position while a friend turned the car over and the car still refused to start.

It appears the fuel pump in the engine compartment was replaced recently, but I'm not hearing a hum from the pump with the ignition in the on position. Should I be?

At this point I'm planning on coming back next Sunday and performing a fuel system/pressure test as per the Bentley. I'm also planning on replacing all vacuum lines (could a vacuum leak be the issue?) as the car has retained the EGR system.

I should ad that the car has had both A/C and heat removed. There are quite a few electrical connections unhooked that I can't find mates for (photos to come later). I'm assuming these are left over from A/C and/or heat systems. Although I can't seem to figure out what's with an unconnected black wire coming from front (pointing toward the front of the car) of the MSD box.

QUESTIONS:
-- Am I on the right track?
-- What other possible issues am I overlooking?
-- Is it reasonable, prudent, recommended and relatively straight forward to remove the EGR system altogether? I ask because some of the reading I've done led me to believe these systems were notorious for high running temps on 2.7s. ...

Any help you seasoned 911 vets could give me would be greatly appreciated.

[ossiblue]

First of all, welcome! You will get lots of help here.

Given what you've posted, there are several possible reasons why the car will not start so the best way to approach this, IMO, is to choose one path and follow it. If that doesn't solve the problem, strike out on another. Point being, try to solve the problem with a logical, step-by-step diagnosis. So, let's begin.

I'd suggest you drain and replace the gasoline with fresh fuel before going further, just to eliminate that component.

You have a 77S 2.7. That model year will not have the fuel pump running with the key in the "on" position. You can test the fuel pump by doing the following: Remove the air cleaner. Turn on the ignition and go to the air intake and gently lift the plunger you see inside the intake. As soon as the plunger is lifted, you should hear the fuel pump run and within a second or two, you should hear the injectors vibrate/squeal as they shoot fuel into the heads. If this happens, your system is now primed and is likely functioning properly. DO NOT HOLD THE PLUNGER UP FOR MORE THAN A COUPLE OF SECONDS IF YOU HEAR THE VIBRATIONS--YOU COULD HYDRO-LOCK THE CYLINDERS. If you perform the above check and do not get the results listed, report back immediately.

Your post also said you had wet plugs. Be sure the plugs and cylinders are free of fuel. If necessary, crank the engine over with the fuel pump relay removed (round, red one) to clear the cylinders of fuel. Pull the plugs and check that they are dry. Replace the fuel pump relay and prime the system (as described above.) Does the car start? If not, report back.

If the car still doesn't start, you could have out of spec fuel pressure, a faulty/leaky/disconnected cold start injector, leaky fuel injectors, or a massive air leak--this is assuming your ignition is truly functioning properly, as you stated. Rather than overload you at this point, do some of the basic checks mentioned and report back. We'll take it from there. Remember, FEEDBACK IS ESSENTIAL and will lead to a solution much faster for you.

When you are ready to perform the fuel pressure tests, you will need to know how to get the fuel pump running with the ignition on. Simply pull the fuel pump relay and find the sockets for pins 30 and 87a. Use a small jumper wire to jump those two sockets and the pump will run with the ignition in the "on" position.

The erg system on the 2.7 is not the heat culprit, it is the thermal reactors. Look to see if the car still has them (they look like round logs bolted by the heat exchangers.) Those, and the five-blade fan killed a lot of 2.7's early. Let us know what you find.

[Flat6pac]

If youre close on your spark, fuel is the probable problem. Either not enough or more likely lack of pressure from the system.
With the key on if you lift the air flow sensor the pump should come on. Pump for a couple seconds and see if there is enough fuel in the engine to start
Pressure from the pump is close to 100#
break the fuel line on the bottom of the accumulator an put your finger over the fuel line. With the pump running there should be no fuel coming out the bottom of the accumulator
If there is, you need a new accumulator because the pump is dumping its fuel back into the tank.
The EGR system removal includes plugging the air box on the right side and you need the injection off the engine to finish the job
Bruce

[boyt911sc]

If the '77S has a CIS, the first thing I would do aside from checking the ignition (timing & sparks), is check the fuel pressures (control, system and residual). So it is mandatory to have a pressure gauge kit for fuel injection available, otherwise, troubleshooting would involved a lot of guess-work. It is not that difficult to make these engines run. Keep us posted.

Tony

[maui44]

Make sure your fuel relay is not bad. You can use one of the other relays to check this out.

You also have a fuel pump fuse. I think's number 25. The fuse box should reflect the proper fuse.

[modelyear1983]

Thanks for the helpful suggestions, guys. It'll be a few days before I can get out to work on the car again, but I'll post results (or more questions) then. Thanks again.

[T77911S]

when i hear that a car sits fopr long periods of time, the first thing i think of is a stuck plunger in the fuel distributor, especially when i hear that the plugs where wet with fuel.
another thing i like to do is to get the easy checks out of the way.
you have spark, that is the first one. do you have fuel? that is another easy one. you can either pull an injector to check for fuel, or you can raise the sensor plate to check for pressure. i like the later on e because this will check for a stuck plunger. (you can also pull an injector, place it in a jar, and check for spray at the same time. the injectors just pop out)

with the key on, raise the air sensor plate. there should not be ANY free play before you feel resistance. you shouold also hear the CIS system "squeal" as fuel is fed to the injectors. if you hear the squeal before raiseing theplate, or there is free movement of the sensor plate, the plunger is stuck, flooding the engine.

if this is fine, do as above and start investigating fuel pressures. (i assume you dont have gauges, another reason to check the plunger first).

plugs should be cleaned with sand paper if they are fouled.

[modelyear1983]

SHE STARTED!

... but she's running like crap.

Got the beast started today by holding open the plunger in the airbox for a few seconds (thanks, chaps!). There's no free play in it.

It's running awful. Backfiring like crazy, popping that little aftermarket airbox de-exploder (correct terminology, I'm sure) all the way up every few seconds.

Most interestingly the FI system is revving the car up by itself in a steady pattern every few seconds as well. Is there something like an isle stabilizer valve on CIS? I had a Motronic 16v Jetta that would do this when the ISV was clogged.

Any suggestions on what might be causing this and/or what I should check next?

P.S. -- This car has a 12-blade fan and no thermoreactors.

[boyt911sc]

Check the fuel pressures and absence of air/vacuum leak in the system. You need a fuel injection pressure gauge kit to do an effective troubleshooting otherwise you'll be doing a lot of guessing. You are doing good and as long as you could make the engine start and idle, you are half way from having a nice running engine (car).

Your next goal is getting all the bugs out after a long hibernation. There is nothing these guys could not fix!!!! Keep us posted.

Tony

[T77911S]

if you raised the senor plate with the key on, then it started, your CSV system is not working. if you held the sensor plate open, the CSV system may be the problem but you could also have a mixture problem due to fuel pressures and air leaks, or just miss adjusted. but fix the first 2 i said first.

idling up and down is another symptom of air leaks, fuel pressure and mixture problems.
backfiring and popping follows all the above.

its called a pop off valve. make sure it is seated/closed as they can get stuck open.

fuel pressures and air leaks first!!!!

there is no ICV on CIS. there is an aux air regulator (AAR) bit as its name implies, it does not function like an ICV. it is ONLY used to raise the idle while cold.

[bigboyracing]

car has been sitting for 6 years went to start yesterday and just turns over
sprayed starter fluid in it and ran for just a second so i don't know if it's the fuel pump relay or pump i changed the relay with another still no run!!!!!help please i have the car sold and can't get it running!!!!!!!