'81 3.0 SC engine problems

[Mythos]

Have been lurking the board for years. Enjoyed following build threads and dreaming of one day owning a 911. I now have an early 911 but...together with it I got quite a few headaches.

Bought the car. Car run perfectly for ~2000 kms (except the oil leaks), engine felt nice and healthy(always started nicely/felt quite good on power). Car was then parked and stayed covered for 8 months while I was away.

Quick details on the car. Was originally a 1971 911 and mid 80s it received a full '79 SC conversion in Belgium. In recent years 2.7 motor was replaced with '81 3.0 SC motor. Car is a mild race build(suspension/safety gear)and a stock engine/gearbox. Car has been running with moderate success locally for couple of years. On paper it sounded perfect since I wasn't looking for a original or 'correct' car but a 911 to drive and to track with minimal running costs. Here are some shots of the engine as it sits today:






I'll try to sum up my problems starting with the main one:

- The car will not start. Didn't know how old the battery in the car was so replaced it with brand new one. Car still doesn't start. Fuel pump running(you can hear it on startup), starter works/turns but you can feel like there is some resistance to the crank/like the crank is too slow. If you do a couple of attempts you get the occasional pop like the car is actually going to start but even if you hold it for a couple of seconds doesn't start eventually.

- Previous owner said proudly before the sale that this one doesn't leak at all. Proved to be a lie since cars was leaking from day one. There seams to be 3 main oil leaks. Pointed with red arrows(altough I'n pretty sure are major enough so you don't need arrows to spot). Leaks when the car stays static aren't so bad but one of them is actually much worse when the car is hot(let's say after a 2-3 h road trip)with the engine running. Should I be worried?




- My car had also the...Toyota throttle problem. Which was quite scary on track but after searching on the forum found out that is something that actually happened to quite a few other owners so I know what to look for to fix it.


I'd love to hear some feedback and since I'm new, and not exactly sure of what has been done to the car, more experienced eyes might catch something that doesn't go along with what I wrote.

[boyt911sc]

What do you mean by 'Toyota throttle problem'? Could you elaborate on it a little bit? Welcome to the forum. Please post a picture your car. We love to see that picture instead of your engine bay. Which is your primary concern, the oil leaks or getting your engine to start and run? Keep us posted.

Tony

[Reiver]

Oil leaks from the cam covers are common and easy fix...make sure they are flat and reseal. Your oil sump cover is bent (engine block drain) and if it's bent will not seal, you need a new one and not expensive....that is all of the oil on your muffler. Those are normal maint. fix's.
Ran when parked.
Check for spark at the plugs and work your way back...coil, wires etc.
Then re post.

[T77911S]

oil leaks:
you have the good valve covers.
first degrease the engine. take it to a car wash with several cans of degreaser. i have even taken a floor jack to get under it better.
get the reusable valve cover gaskets. trust me, they are worth the money. note that they require very little torque to seal.
remove the valve covers and clean all that up. run a die on all the studs to clean them up to get a better torque on the valve covers.
you have a little oil on your chain boxes. those gaskets are easy to replace.
but clean up the engine to verify where the leaks are.
next oil change remove the pan on the bottom of the engine. note its orientation. replace the gaskets. run a die on the studs here too.

you may be leaking at the oil return tubes. cleaning the engine will reveal where the leaks are from.

no starting:
could be many things. is the gas good. does it have gas in it.
are you getting spark are you getting fuel.

turn the key on. remove the air filter and lift the sensor plate. you should hear a loud squeal coming from the CIS. try to start it after lifting the sensor plate.
there should not be any play in the sensor plate when lifting. you should feel resistance.

slow starting:
clean the battery terminal ends.
clean the cable end where is connects to the body
clean the connection between the body and tranny.
clean the batt connection to the starter.
starter could need a rebuild. go here for my rebuild.
http://forums.pelicanparts.com/porsche-911-technical-forum/631173-solenoid-starter-rebuild-finally.html

[vash]

give us a pic of the overall car!!

none of those oil leaks look that bad.

i like T77's advice. if i cant get a car to start, i do two things. look for spark first, then move on to explore fuel. sounds like you need to get the starter to turn the motor over properly. put a mulitmeter on the battery to give it a quick health check. charge it up if needed. (if you been attempting to start the car a lot, you may need to do this). run thru the battery check list for sure. check them grounds!

an 81 car , i kinda remember some safety switch that will not let the fuel pump pump unless the car is running or attempting to start, i could be wrong, but i kinda remember having to jump a few terminals at the relay. i could be wrong...do what T77 said about flipping on the ignition and lifting the air sensor plate. you should hear the injectors let out this anemic sounding "scream" or whistle. dont do this too much or you kinda squirt too much fuel.

while the air cleaner is off, if the car has a pop off valve, make sure it isnt popped off, or held opened or anything. i have this spark tester thing. super cheap and is easy to use.

[Mythos]

Some photos of the car(I'd open a proper thread if I can get it work and out of the garage at some point!):






Car was working perfectly before getting parked for the last 7-8 months. Car has half tank of gas and now brand new battery. I will check what you guys suggested and take it step by step.

Anyways I' more worried about the engine not starting because the oil leaks is something I was almost expecting. Happy to hear that it isn't as bad as it looks.

TT77911S what do you mean the good heads?

About the 'Toyota throttle' I meant the sticking throttle situation. Where the throttle sticks WOT and stays there for flip seconds even though you have lifted. Here is a mention:

http://forums.pelicanparts.com/porsche-911-technical-forum/828778-help-few-scary-toyota-moments.html

This happened to me a couple of times on track but never on normal driving/cruising. (Apparently there are multiple things that can cause it pedal side, bushings, throttle body side).

P.S: About the airbox, I'm pretty sure my airbox is modified inside...(The fix to stop the melting due to backfire) but has been working like that for years and I doubt that has something to do with my new found problems.

[theiceman]

you say you hear the fuel pump . i think you may me hearing the ignition squeel as the fuel pump will only run while cranking.

with the ignition on take out the air filer and feel for the air plate . lift it momentarily ( as you can flood the cylineders
, you should definitely hear the pump run at the front of the car.

[boyt911sc]

The car is an '71 with an '81 SC engine as per post. Unless a complete re-wiring was done, the FP for this particular car should be running when you turned the ignition switch to ON/Run position. By the time you turn the ignition switch to START position, the fuel lines are all pressurized by the running FP.

Tony

[jeffs9146]

I have a 82sc 3.0L and had a very similar problem when I first installed the motor. It turned out to be vacuum leaks.

The late 3.0L's will not start with vacuum leaks.......PERIOD!

I pulled the motor and replaced all of the intake gaskets, vacuum lines, airbox, injector seals and runner rubbers. The airbox had multiple cracks and will get worse the more you try to start it and it pops inside the intake.

Once everything was sealed I hooked up a cleaned up shop vac with he hose reversed to blow and hooked to the intake and duct tape sealed. Turn on the shop vac and spray soapy water all over the intake connections. If you have a leak you will see it!

[Porschephanatic]

Welcome Aboard. When this happened to me, it was the CD ignition box. Oil leaks look minor. My 2 cents.

[Mythos]

So after reading everything here and searching through old topics I saw a repeating pattern about a problem previous owner had. The car was repeatedly having issues to start when hot, when the car cooled down it started perfectly fine but if left hot for a couple of minutes then wouldn't start(also happened to me but never paid enough attention at the time). So I thought it was the fuel accumulator as many members had exactly the same problem and fixed it by replacing that part. (Maybe staying so many months out of use made matters worse).

I ordered everything and changed the fuel accumulator to brand new bosch unit plus a new fuel filter. Part of the procedure according to the manual is also to lift the sensor plate and it did indeed make the noise and -I think- fuel was flowing to injectors.

So gas in the car, brand new battery, brand new fuel acc. , brand new fuel filter next day I start the car and it starts with the first try without even needing an extra long turn on the key. Idles roughly but good I try to add some throttle through the hand control everything fine. So I have to move the car relatively quickly(because of the extreme noise/neighbours) so I don't give it proper time to 'warm' up and slowly starting backing out. Car stalls. Never started again. No matter what I tried a bit more throttle, a bit less throttle. leave it to cool. Nothing.

Fuel pump works. Fuel is coming to the engine, there is ignition/spark...hell it even run for a little bit but now engine dies the minute I stop cranking the key. I think...it feels like maybe has more fuel than it should? Like it gets flooded but could be wrong. There was some fuel(?) coming from the exhaust, plus slight white smoke after some attempts when I walked away from the car. Really can't understand what's happening...

[tirwin]

Starting after it cools off could also be the CDI box. Assume you either have Bosch or PermaTune?
Have you checked plugs or coil?

[reddogmotrsprts]

When you turn the key to the ON position, you should hear a high-pitched whine from the CDI. Check the connection to the CDI box before assuming that the box is bad. Check that you're getting spark, ideally on all cylinders.

You're looking for a strong blue/white spark that should jump a good 15-20mm from the plug to ground. I've seen your symptoms on a car with a new coil that proved defective. In that case, the spark was more yellow/orange and didn't hurt as much when I put it to my tongue.

When you pull each plug to check for spark, immediately snap a photo, and show us the two shots that look most different.

The engine needs to turn over quickly when you turn the key. If it's not, you can skip checking for spark. I'd start by making sure you have a solid ground between the tranny and the chassis; just use jumper cables or a new ground strap. If that helps your starter speed, it may help your spark issue as well.

Finally, try to limit the changes you make while debugging this problem. You will get plenty of advice from the forum, but the more changes you make, the greater the chance that the problem is complicated but new issues and the harder it will be to identify.

[boyt911sc]

Originally Posted by Mythos

So after reading everything here and searching through old topics I saw a repeating pattern about a problem previous owner had. The car was repeatedly having issues to start when hot, when the car cooled down it started perfectly fine but if left hot for a couple of minutes then wouldn't start(also happened to me but never paid enough attention at the time). So I thought it was the fuel accumulator as many members had exactly the same problem and fixed it by replacing that part. (Maybe staying so many months out of use made matters worse).

I ordered everything and changed the fuel accumulator to brand new bosch unit plus a new fuel filter. Part of the procedure according to the manual is also to lift the sensor plate and it did indeed make the noise and -I think- fuel was flowing to injectors.

So gas in the car, brand new battery, brand new fuel acc. , brand new fuel filter next day I start the car and it starts with the first try without even needing an extra long turn on the key. Idles roughly but good I try to add some throttle through the hand control everything fine. So I have to move the car relatively quickly(because of the extreme noise/neighbours) so I don't give it proper time to 'warm' up and slowly starting backing out. Car stalls. Never started again. No matter what I tried a bit more throttle, a bit less throttle. leave it to cool. Nothing.

Fuel pump works. Fuel is coming to the engine, there is ignition/spark...hell it even run for a little bit but now engine dies the minute I stop cranking the key. I think...it feels like maybe has more fuel than it should? Like it gets flooded but could be wrong. There was some fuel(?) coming from the exhaust, plus slight white smoke after some attempts when I walked away from the car. Really can't understand what's happening...

Mythos,

Your car (chassis) is a '71 as you mentioned in your initial post. And subsequently installed an '81 SC CIS motor as shown in your pictures. I highlighted the section or information that does not make sense to me. Why would a hand throttle be used in a late SC engine? Did you use the older CIS components for the '81 SC? Keep us posted. Thanks.

Tony

[Mythos]

Correct, car shouldn't have a hand throttle. As mentioned in the start chassis is a '71 was converted to full 2.7 '79 SC and then motor to a full '81 SC.(All engines European versiosn)

From what I see the car has the correct CIS components. Maybe the hand throttle thing is a leftover from in between stages? Previous owner mentioned something about removing cruise and/or the cold start enrichment thing(or something like that) because some time in race conditions could malfunction or interfere with the throttle...does this make any sense? (I think I've read about that issue before here as well...)

Problem is I can never be completely sure about what the previous owner has done. Although engine is mostly stock and all the modifications are...towards the correct direction! Either simplifying or making stuff more reliable for hard use.

I have no experience with early 911s and there is limited number of early cars here(in Greece) and even more limited good Porsche mechanics/shops.

Haven't checked spark thoroughly yet(car is stock no Permatune or MSD) -but doesn't sound like it- will do since I'm running out of things I can check by myself. If someone can think of something I'm missing...

*I'm really getting frustrated with the whole CIS thing and want to ditch everything and put a basic EFI solution in...

[reddogmotrsprts]

Take a breath, you're not far from solving the problem -- the car ran fine not long ago. The resources required to get the car running correctly again are likely dwarfed by the effort to switch to EFI.

Each potential problem you eliminate brings you closer to the solution. There are plenty of good suggestions in this thread. Try not to change more than one thing at a time and simply work the problem.

As hard as it seems, you can do this, and it sounds like bringing it to a local shop is a recipe for disaster.

[boyt911sc]

Originally Posted by Mythos

Correct, car shouldn't have a hand throttle. As mentioned in the start chassis is a '71 was converted to full 2.7 '79 SC and then motor to a full '81 SC.(All engines European versiosn)

From what I see the car has the correct CIS components. Maybe the hand throttle thing is a leftover from in between stages? Previous owner mentioned something about removing cruise and/or the cold start enrichment thing(or something like that) because some time in race conditions could malfunction or interfere with the throttle...does this make any sense? (I think I've read about that issue before here as well...)

Problem is I can never be completely sure about what the previous owner has done. Although engine is mostly stock and all the modifications are...towards the correct direction! Either simplifying or making stuff more reliable for hard use.

I have no experience with early 911s and there is limited number of early cars here(in Greece) and even more limited good Porsche mechanics/shops.

Haven't checked spark thoroughly yet(car is stock no Permatune or MSD) -but doesn't sound like it- will do since I'm running out of things I can check by myself. If someone can think of something I'm missing...

*I'm really getting frustrated with the whole CIS thing and want to ditch everything and put a basic EFI solution in...

Mythos,

2.7 liter engines are not SC engines. SC's have 3.0 liter motors. So far you have not done any diagnostic test to determine the root cause/s of your problem/s except replacing parts after parts. Why did you replace the fuel accumulator? Was it defective? Have you checked your fuel pressures? Have you confirmed that your motor does not have significant vacuum leak? These are some of the steps you have to be proactive if you want your CIS engine run good. Switching to EFI is not a solution to your predicament and a decision you have to make.

Look for someone who knows about CIS and start from there. Your frustration about CIS is due to your lack of understanding how the system works. It is a very reliable and dependable system if you understand the basic principle behind CIS. Actually it is maintenance free if you keep the fuel pressures within spec and free of vacuum leak. My '79 SC has not been to a shop for more than 20 years except for emission sticker. The last time it was in a shop was for full body paint and has been running since then.

Tony

[Bob Kontak]

Originally Posted by boyt911sc

Your frustration about CIS is due to your lack of understanding how the system works. It is a very reliable and dependable system if you understand the basic principle behind CIS.

Originally Posted by reddogmotrsprts

Take a breath, you're not far from solving the problem ............

Given you may not have an old-man CIS expert nearby, you need to do it yourself.

Divorce from the frustration and view it as a moderately challenging puzzle. Fixing your CIS problem is far less expensive than what you have already spent in Euros.

You really should buy a set of CIS pressure gauges. Primarily to see if you have a system rest pressure loss.

Also. as Tirwin mentions, make sure you have spark AFTER the car dies. I am not sure your car is dying after it completely warms up or if it dies shortly after the car is started.

[theiceman]

i think this is going to be one of those " lets get back to basics" theads as Tony eludes to. A 71 converted to a 79 ? then to an 81? who now what level the wiring is at even to support this configuration .
I think PO is going to have to take a deep breath , confirm spark and get a hold of come fuel pressure guages..

with real data this can be resolved..

things i wonder about ...

does the fuel pump run like a 71 or like an SC including the safety cut off ( is it wired in even )
does the air plate have the correct " resting gap "

[Mythos]

Again thanks for the encouragement and the suggestions.

Tony I tried to shorten 'converted to a '79 SC(outside panels and almost everything mechanical) with a Carrera 2.7 motor' so it looked wrong. Not that it's important but the '81 3.0 SC motor was a relatively recent conversion(~2010).

Also I didn't just replace parts. Battery was completely dead and replaced after I first tried to jump start the cars with wires. (And I now have a frame of reference on how old it is)

I went with fuel acc. because the 'symptoms' fitted and it was a problem that even the previous owner had so I thought I might be lucky and it was that simple. Since I did that I also changed the fuel filter that was an old item I'd like to change anyway.

That said I didn't test first the old fuel acc. before replacing so...yep I might have been able to save some money.

What I don't understand is why after the change the car started with the first attempt while all the last week I tried a 20 different times with no success.

What I don't understand even more is why after that it was impossible to start again.

I'm after looking spark more thoroughly although as I said...it feels like a fuel problem to me(I have zero experience with 911 engines but not zero experience about cars).

I also checked for some loose or cracked hoses or something electrical moved(a ground loose). Nothing. Car looks exactly as I left it 7-8 months ago. (If there is a leak I think the car should first run to have any chance of identify it)

* the iceman I think the fuel pump runs like a '71 since it starts the moment you put the key on(which shouldn't happen to a 3.0 SC).