I absolutely flat out give up.

[RoninLB]

Originally posted by Superman
.

My main suspicion (not trying to insult the mechanic) is that the fuel system is the problem and that the problem is volume. Crushed fuel line, line packed with rust, tired fuel pump, all will prevent the engine from getting a sufficient volume of fuel under load and at high RPMs. The volume test is one of the tests I have suggested. Get the Bosch CIS FI troubleshooting book. Or look in your little spec book, find out how much fuel the pump is supposed to deliver in a given time. Detach the fuel supply line at the fuel distributor, stick it in a bottle and run the FP (turn on the key and life the sensor plate). If you're not getting the specified volume, then this is your problem.

stormcrow says.."If you can redline the car by feathering the throttle, then you may have a fuel flow problem"......................

bell says.."if the fuel line is damaged it will severely restrict high volume flow."

I said.. "I would not be suprised if the fuel tank filter is dirty"

..So Shawn...How is your fuel volume doing??? .. You did do this test?? ......................Ron

[thrown_hammer]

Quote originally posted by me.
"I am going to rule out the fuel system (for now).I will concentrate my efforts on the spark side. First I will trade out the CD unit. Then check all my connections. Sound like a plan?"

It's in the plan. First step was to rule out a spark issue. I think I have done that now.
Now on to the fuel side. I am going to measure the volume and spray pattern at the injectors with a similar set up to John Walkers test tube rack. Then work my way from the injectors to the tank.

[RoninLB]

"Now more than ever I feel like a sparrow headed for a plate glass window...REPEATEDLY "
"Now if you will excuse me I am going to nail one foot to the floor and run in circles."

Shawn...Sorry for my last post..sometimes I can be too literal..hate to lose a pelicanhead to the funny farm..unless I get there first and need a friend or a nail............Ron

[Kemo]

hammer...

Thanks for posting your issues here. I dont have an answer for you...but I'm really picking up alot of information from your thread. Im a little troubled at the part where you said your "foot went to the floor and your engine drops to idle". Thats scary, like maybe the butterfly flipped over in the throttle body. I think there was a thread started by SCWDP founder Leland Pate that talks of throttle linkage adjustments to gain power. Good Luck, and thanks again for posting your progress.

[thrown_hammer]

Ron,
I have an extra nail.

I went out and looked at my linkage. It popped off in the engine compartment. I think I need to order some bushings.

[47silver]

sounds like how a rev limiter acts except for the ability to finally red-line, i vote cdi

[Hal & Linda]

This sounds a lot like a problem someone near by had - turned out to be the catalytic converter had self distructed on him...

The problem was that without the right pressures in the exhaust system, the car ran poorly at higher rpms. While you don't have the catalytic converter, have you checked the exhaust system to see if that's possibly the culprit? I recall you replaced something in your exhause system, but did it get checked after it was replaced?

[emcon5]

Originally posted by thrown_hammer
When I replaced the coil with a Pertronix flamethrower the car ran great for about a week,

Things that make you go hmmm.

Is that a direct swap in? As I understand it, the CDI coil isn't a coil in the traditional sense, but is really a high voltage transformer. The windings are not the same.

Just thinking out loud.

Tom

[john70t]

As if you needed it...here's another tangent.

Other than the coil issue, which was gonna be my last guess(darnnit!)
"When it is cool out(like in the morning) it sputters less. When it is hot out it almost dies when I floor it above 4000. "

Perhaps instead of too little fuel there's too much? O.k., o.k. I know what you're thinking:high rpm=high fuel consumption.

But....what if the previous owner never drove the car, only like a grandma when he/she did, and bought crappy gas.

1. The air vane in the CIS pushes up on the fuel plunger exposing more slot for more flow, and the WUR acts as a counter-force on the plunger (when the engine is hot) by allowing fuel pressure to push in down, limiting fuel. The air flow past the meter speeds up but doesn't move it. (did I get that right?)

2. Problem: The plunger never reched the top of its potential travel before and, like the end of a brake MC bore, that part never got cleaned by the piston travel and a giant chunk rusted away from the wall and/or makes the plunger stick when it should be sliding.

o.k. it's just a tangent. I like the WUR and coil answers better.

[scarebus]

Hammer,
Most notorious sputtering on cis with points, is, dirty points.
Shoot some contact cleaner at the point contacts, cut a small
piece of clean cardboard off any box ( for instance, box that comes
with new points or rotor), sandwitch between the points( when
closed) and slide the cardboard back and forth several times to
clean the points. That normally fix the sputter.

[thrown_hammer]

The entire exhaust system is new. I have Bursch headers and a Bursch 3M sport pipe. Anyone nearby have a 2 in one out muffler I can borrow? Maybe the 3M is too restrictive?It is designed for cars with MFI.
The points are also new. I will go ahead and clean them since it will take little time and it's free.
The Bosch CD box I got has the same #'s cast into it and dimensionally is the same.
The car did sit for about two years while it was transformed. But I have cleaned the tank screen, replaced fuel line(with the same size line), replaced the fuel pump, replaced all fuel injectors, cleaned the little screen inside the WUR.

I am beginning to suspect the fuel dist. I am currently collecting babyfood jars from my son so I can check flow from all the injectors, the check flow from the pump. That should tell if it's the fuel dist. or not. Does anyone have the flow numbers for the injectors and fuel pump for a 1975 911S?

I appreciate the brainstorming session. Good things will eventually happen.

[RazorRacer]

Have you adjusted your timing?

[thrown_hammer]

My mechanic adjusted the timing. He also checked it at high RPM for the advance.

[johnco]

this may not help you, but...
I had a similar problem many, many years ago with my 924. against better advice, I removed the fuel distributor and stripped it down to nothing. every orifice was partially stopped up with rust and deposits. after cleaning every thing and taking 2 days to figure out where all the o-rings, springs and tiny pieces went, I re-installed it and everything was good again. I also learned that I could take an injector out, tap it upside down on something hard and tiny bits of rust would fall out and I'd get my spray pattern back without having to buy new injectors

[thrown_hammer]

I have been thinking about doing that this winter. How insane is it in there? Is there a expploded view anywhere I can look at? I mean if it's bad what hurt is tearing it apart gonna do?

[johnco]

it's quite a surprise after taking out the last screw and everything explodes into many parts. do it slowly so you can remember where everything went. I had no exploded view, just an exploded FD. everything was caked up with rust colored deposits I had to scrape out. that was 20 something years ago and my memory is fuzzy, but I'm sure I could remember where everything went if I saw another. it was a trial and error thing putting it back together until I finally figured it out. just be sure not to drop anything. tiny springs, o-rings, metal pieces and the all important piston in the middle. if I remember correctly, these things were not repairable and no exploded views were in any book I could find. a replacement was $1200 back then so it worth a try. and it worked.

[avendlerdp]

I found some place here in L.A. that sells re-done fuel distribs. for less then $250. This was a few years ago. I had one clogged with rust as well. It would drop a cylinder at above 4000 rpm. Got new fuel distrib., fixed!

Alex

[thrown_hammer]

I found a rebuilt fuel distributor for $450. After I check my flow and if that determines it is the FD, I will tear it apart and try to clean it. If it doesn't work (or I drop something) I will buy a rebuilt.

[RazorRacer]

Just fishing here. Does your distributor have a vacuum advance / retard? If so, try to disconnect it and see how that helps.

[SeaDweller]

When the injectors were replaced, were new insulators also installed, with new "O" rings? I wonder if a possible vacuum leak though the injector insulators might be the culprit?