Timing, idle messed up. HELP! Longish

[davis911s]

I need help. The car is a 77 with 2.7 CIS. I was verifying my engine timing, to help see why my engine runs hot. My tach doesn't work so I used the timing light to check, My idle was at 1100. I tried to slow it down but when I turned the idle adjustment screw it the engine would stumble then stall. 1050 was the lowest I could get the car to maintain an idle.

Then for the timing, my cars spec says 15ATDC, When I checked it with the light it was running AT TDC. I loosened the nut on the distributor and moved until it was at 15ATDC. The car ran VERY POORLY.
As a side note the distributor had not been moved in at least the 4 1/2 years I owned it. I think it was right where it was.

There are also lots of little marks on the pulley, but I am sure I am using the right one. It is the left one in the group of two side by side.

I am really frustrated with this, I don't know where to start. And I want the car running as good as possible for the roundup.

I do not know what my fuel mixture is. It was running lean a few days ago (light coloured plugs), so I richened it by 1/8 of a turn. The plugs today were darker. And I have heard richer is safer than leaner.

PLEASE HELP, Tell me what to do. I have access to lots of tools. BUT NO Porsche tools or Mechanics

I can't understand why the car won't let me turn down the idle, or how these timing marks are working. Nothing makes sense. And to make matters worst my "101 Projects...." is in a box unpacked in my garage with my furniture still.

Shawn
BTW my fuel pump relay is ticking at idle. I traded relays and they all do it. If I give a little gas the ticking stops.

Thanks

[davis911s]

Bump . Please help.

[Early_S_Man]

Shawn,

Putting this thread's symptoms togther with your 'clicking' fuel pump relay ... sounds to me like there is a problem with your ignition switch! There is no reason for the fuel pump relay to click ... unless the power is being interrupted to it by a loose or intermittent connection, and whatever is causing that to happen could also be interrupting power to the CDI-unit and be causing an erratic/odd idle condition.

Or, perhaps there is a problem with the airflow switch contact, and the clicking relay IS THE ENTIRE PROBLEM, and is affecting the pressure to the CIS system to a degree bad enough that it is not stable enough for idle speed to 'settle' down.

[Early_S_Man]

Shawn ... try removing the fuel pump relay, and putting a solid 12-ga wire jumper from pin 30 of the socket to pin 87a, and see if the idle problem goes away.

[davis911s]

I am still messed up.

Warren thanks again for all your help over the years.

I went out to the car to "jump" the relay. Only the damn thing wouldn't tick. So I thought it would only tick when the engine is HOT. I cleaned all the conections on the relay and again on the 14 pin connector in the engine compartment. Let the engine warm up (210) still no damn ticking. I will try it again tommorow at higher temps. (it was 230 when I had the problem.)

ANYWAYS, I attached the snap on timing light to try and set my idle lower, it was still over 1100 at idle. (It has RPMs on it too)
Here's what I did
-I disconnected all the throttle linkage from the engine.
- turned the idle screw as low as it would go, clockwise.
-then I kept turning the mixture screw until I had 975 ish for RPMs. The RPMs were jumping between 970-1050.
- Once I had the idle I re-attached the linkage.
- the idle was stuttering an was 780ish.
-I turned the idle screw until I again had it jumping around 980.

This is probably WAYYYYY wrong and my mixture is probably out to lunch. But it idles nice, and ia a lot quieter than before.

I drove it for 2 minutes home this way (from my garage) and don't want to drive it until someone tells me I probably won't mess anything up too bad.

I hope I can figure this out.

My timing is still set AT TDC not the 15 ATDC the specs call for.

PLEASE HELP A DUMB Canadian Porsche owner



Shawn

[davis911s]

OK went for a drive toady, temps got to 230. The ticking in the relay is gone. I am assuming the cleaning of everything fixed that.

BUT I still am unsure of the reason why it is set AT TDC, and idling etc well. I am thinking this is why it is running hot. Should I Set IT TO 15 ATDC, then get the idle set ok, or what what should be done first
1- Fuel mixture
2- timing

The idle will obviously change with either so I must set one of these first.

I DO NOT want to wreck anything here.

Shawn

[Early_S_Man]

Shawn,

Your timing should be set at 5° ATDC, as shown on the sticker below, and as for all other 2.7 CIS engines ... it is the leftmost of the four notches grouped as follows: 5° After TDC, 0° TDC (Z1), 30° Before TDC, 35° BTDC.

[RoninLB]

Shawn...I got this Calif. 2.7 from my brother about 7 years ago..The first thing I did was disconnect the dizzy vac. line then set initial timing about 2-4 deg BTDC..figure your initial around your total 35 deg. and see what happens. I don't think you'll wind up w/more than 5 deg. BTDC...this will mellow out your advance curve without the smog requirement restrictions that went down in 77 for the 911. The rest should be a routine tune up w/mixture adj./setting...I assume you don't have other electrical problems...I assume you checked the Beru wire/spark plug connectors...I use the cheap Gasometer, or what ever it's called, for setting fuel mix. .costs around $125..I would get the routine BS straightened out 1st , then see what your left with...you may wind up w/CDI/coil headaches latter after the basic BS is taken care of. The fuel/elec/ign. systems are relatively uncomplicated.....Ron

[davis911s]

The ticking was back when I restarted the car 30 minutes later. So it is not when it is hot just on warm restarts????

Thanks guys
Warren the sticker on my engine said 15 ATDC. So I just set it to that. But now reading your post I am thinking it might be the 5 deg due to the fact that the car doesn't have thermals.

Anyways I set it to 15 deg ATDC then I set the idle to 1000. When I drove the car it worked better seemed to have more initial pickup.

I drove the car and the temps stayed around 220, so a little lower.

Ronin I don't thinkl I have any other electrical problems. The spark plug wires and connectors are only 10,000KMs old so they should be good.

The part that is confusing is that the timing has NEVER been changed ion the 5 years I had it, so it has been wrong for a LONG time. Now I don't know if I should leave it at 15 or change it to 5 deg as Warren says. Warren you are ALWAYS right so????

Shawn

Once I have the timing where it should, be I need to get to a gas analyzer.

[Tim Polzin]

Make sure that thing is running right for the 12th of July Shawn!

Tim

[RoninLB]

I believe the 15 deg is stock on some models. In order to make it smog friendly at the cost of engine life/heat. At 15 deg the vac. adv. must be operating. To use the 5 deg adv the vac line should be plugged. There is a detailed article in Pano concerning this situation involving some '77 911s.........Ron

[davis911s]

Ronin any idea what issue of Pano? And shoyld I leave it at 15 deg or block the vacuum and run it at 5 degrees ATDC. Which would work berst, and run cooler?

Tim- No worries the car WILL be ready by then. Nothing short of a blown engine, or totalled car will keep me away

Shawn

[Early_S_Man]

Shawn,

Was your car originally a California car? That would account for the 15° ATDC timing that kills magnesium cases and power, too!

You can use the 5° ATDC timing with the vacuum connected ... that is what 49-state cars used, and the 2.4 engines before the 2.7 engines! The vacuum module provides 10° of retard ONLY at idle!

If you disconnect the vacuum, use 5° BTDC, because that is what your centrifugal advance was designed to be set at. All of the specs from the '72-'73 spec book in the following thread apply to your distributor ... which has identical specs to the '72-'73 2.4T distributor!

distributor lube...

[RoninLB]

Shawn...the info is a copy from Pano in the Up-Fixin series...I'm in la la land so I can't give you hard info..I plugged the vac line, then found total timing a about 33-35 deg. That should be a 5 deg. initial advance. The engine will run thru the rpm cleaner. The eng. should run cooler in the 2.5k - 3.5k range. If you get in touch w/me in Sept. I will send you a hard copy...Ron

[alan911]

The Spec. for 15 deg. was for California cars I think. It will run sucky this way. I keep my '77 (non cat) at the Z1 (TDC) plus or minus 2 deg. Been running fine for 20 yrs this way.

Early-S, My sticker on the fan shroud says 911S-169.3 CIS and set ign. @TDC +/- 2 deg. I know I've got a 2.7 ! what gives with the 169.3 ?? Something to do with SC ??

Shawn- I suspect you have other issues that need attending to. 230 is a little hot. A lean mixture is going to run hotter than a rich one though.

[davis911s]

Thanks again I will plug the vacuum and set it to 5 DEG.

Alan is your vacuum blocked off? I know my loop cooler is NOT working, the thermostat is messed up. So that will NOT HELP, But I want it to run as well as possible. I am going to take my thermostat out and see if it is just seized.

Anyone there with a 77 CIS tell me exactly how theree's is set. ie timing, plus how many turns for the idle screw and fuel mixture. Just count how many turns to a full stop for each then set it back exactly where i was?? I know that is a LOT to ask but it would give me a great starting point

Shawn
77 Targa that I love!

[alan911]

I'm getting confussed with all these posts. I assume you have a 1977 911S with CIS yet you're getting specs for '73s and 74's and timing marks for an SC.

Do you have the sticker on the Fan Shroud ?? If so, you must go by that, whatever it says. Also, which distributor to you have Marrelli or Bosh ? They came with either.

My '77S has the Boshe Dist. with one vacume line. Timing is set at TCD with Vacume connected.(for some reason the UK specs. are 5 deg ATDC ...go figure) If you disconect the vac line it will run like **** (no advance).

My '77 dose'nt have cent. advance just vacume advance and I suspect yours is the same. Don't block the vacume line !!!

Can't help you with the mixture. I never mess with it. once it's set it stays set and have never touched it in 20yrs either. don't want to take the chance of not passing smog this year. Plus, counting the turns from some other vehicle isn't going to do you a lot of good.

If you cooler isn't working that would be a very, very good reason why your running to hot.

[Superman]

Okay, I'll join the fray, just to complicate things. First, if you have points, then they need to be in good shape. Distributor cap and rotor too, and ignition wires, spark plugs, etc. Make sure your ignition system works fine. then adjust.

JW likes to time these engines at full advance. That would be 35 degrees BTDC at full advance. If this results in detonation (knocking, pinging), then back it off until the detonation goes away. If there is a "real" way to set ignition timing, that is it.

Fuel mixture would be last, except that resetting the mixture may change idle, and it also may change the engine's detonation characteristics, so you would need to check that again.

I too wonder whether the throttle plate switch may be tripping the FP relay.

[davis911s]

Alan yes it is a 77 with CIS

The distributor has 1 vacuum hose, and the vacuum works (sucked on it )
I had already disconnected the line before I read this.....It ran like you said.

Now my sticker says 15 ATDC, but it was always set ATDC. I set it AT TDC! It was there for 5 years and ran fine. But the sticker said otherwise as did all the posts so I was concerned.

Now when I had the vacuum disconnected it was running crappy and popping. (I luckily have an airbox)

It is running same as before now, RPMs around 1000 at idle. I am going to TRY to find a gas analyzer tonight!

I know the loop cooler is causing part of my problem but I thought there was more to it, Without the cooler should the temps hit 230 regularly? The car would hit 230 in about 5 minutes- Highway around 70 MPH, temps around low 80s F.

Thanks again everyone, (WE will figure this out )
Shawn

[davis911s]

Superman, what do you mean by the throttle plate and the FP switch??

The plug wires are less than 10,000 kms old. Plugs are new, Points are set to specs and are a year old, as are the distributor cap and rotor.

I misted the engine compartment last night with water, looking for sparks to indicate a miss (brother-in-laws idea) and there was no indication. He said that if there was a miss it would be life a fireworks show (kinda)

Hope to see you next month Superman???

Shawn