PorKen

toofast928,

"Why did you disconnect the vacuum retard from distributor?
It only retards the timing on deacceleration, Nothing to do with power gain/loss right?"

One less hose!

Slightly faster advance on the ported side?

John Struthers

Oddly,
Earl my old neighbor sold his 911 and his 55' Chev big block.
Now he has a new MC 320 Kompressor mit der sport package.
This all leads to two things.
1. Earl also picked up a 69 SS, big block that has sat in a barn for 30 years.
2. Since Earl is in the West Texas Oldtimers Club He knows all sorts of car folks. One of whom owns Racer Edge in Odessa . He, in turn, has a chassis dyno.
This harkens me back to the COST of Dyno work on my earlier reply.
Since the cost per pull is $25.00 -recommends 3 pulls per session = $75.00-
I figure tracking in pure HP/Torque numbers the cost and benefit of bolt on performance components just got affordable.
Talked to the owner today and we will start baseline, either the 29th of Dec , or, weekend of 9-10-11 JAN item #1 on previous reply, plain street not even a tune-up and will progress from there.
Will dyno after EVERY mod from then on in.
This will be started on Pattycakes with the hopes that I will have another early, post CIS, 16v, 4.5L. mule (Sorry CIS folks) by early summer so I can keep Pattycakes as stock as possible.
I will try to diligently list things down to spark plug gap and advance.
At this time does anyone have recomendations on pre-pull things to do?
Vac line on/off... advance ect...

Weissach1982

I have a slight problem, I installed all the Euro parts on my car and tryed starting it and the motor wouldn't stay running, sounds like it was backfiring and loud popping. I heard the AFM ''barn door'' banging against inside the housing and it wasn't responding the throttle being opened or closed. The vaccum advance hose is connected and all the hoses that I can recall that had to be connected or plugged are done. Does anyone have a clue, maybe vapor lock or some kind of vaccum leak? It sounds like it doesn't run on all cylinders. Can't be anything seriously wrong because it wants to start up but it wont. Any Help?
Thanks
Cory J.

mark kibort

whats up with the microswitch removed? did you mount the switches or full throttle switch where couldnt see it?? that enrichment switch is CRITICAL

MK

mark kibort

Cory,

Ok, the terminal on the microswitch (euro) is pin "#3 it is the full throttle switch leg. connect the other wire to the center (its called #18) I think as the microswitch is on the TB , is the bottom and center pair of terminals. the terminal #2 is the idle leg, and that can be ignored

Next, poping , backfiring, wont run??????you got a vaccum leak. probably all or most of the runners. did you use new gaskets?? if not, thats the issue. you can do two things, remove the spider legs and remove and replace, but if they are stuck on the heads, you are kind of screwed. lots of work. in that case, use make a gasket stuff and put it back together. If they are on the runners , scrape off with a razor blade, lightly sand on a belt sander or hand sand with a block of wood, and replace with new gaskets.

NOW, first to verify, take a screwdriver and shove it down the AFM. (dont worry , it wont get sucked in when the engine is running. Obviously, forget about putting the air filter on and cover. you can use your fingers too and have someone else start the car. guess what, it will run, proving you have false air.move the AFM door slowly more open or closed til it runs smoothly. Scots did this very badly. when we did the gaskets, it ran like new!!

MK

mark kibort

LOOKs like the S4 pressure regulators are up to 10psi more, but that could be a funtion of a higher pressure pump too. up to 86, they all used the same fuel regs and fuel pumps. at 87, the fuel pressure went to 3 bar at idle and 3.8 bar with engine not running and fuel relay jumped. (compared to 2.5 bar on a 83ish ) thats 36psi compared to 55psi. on the jumped fuel pump relay pressure.

So, the quick answer could be to get a S4 regulator instead of a RRFR, for a quick fix. (or two of them i should say)
MK

Jon F

Did you fool with the ignition wires at all, Cory?

Jon F

I believe PorKen has a standard US throttle body, with the microswitches mounted on the linkage-side.

mark kibort

I posted a correction to the other 928 main list. The main point of posting this again, is to start thinking about how to raise pressure without buying an additional regulator to raise fuel pressure. the two fuel regulator systems, may be a unique opportunity to raise pressure by just capping off one of the return lines!!! maybe the older models had build in adjustability, and we didnt even think about this!!

Here is my post to the other list. comments welcome

>>>>>>>>>Opps, in the manual, it was talking about 85-86 fuel pressure reulators, not 87 on. Looks like there is a BIG difference in pressure starting with the 87 and on. the pressure at idle goes from 2.5bar(36psi) to 3.3 bar(48psi), and test pressure with engine off from 2.5 bar to 3.8 bar. (36psi to 55psi). However, since you need two of them in the earlier models, they could the same but with one, there is only one return line to the fuel tank, and that could raise the pressure in itself. This brings up another possibilty, we could just cap off one of the lines, so all the pressure is bled off through one fuel regulator, thus raising the pressure. This may be a good fix to increase pressure by 5-10psi. anyone with a pressure gauge on their car, should try and pintch off one of the lines of their regulators and see how much the pressure goes up to . (should be an easy test)

I still wonder what the reasoning was from porsche to use 2 fuel regs. (and only one on the S4) also, I wonder why the S4 needs two pressure dampers.

In any event, we will try the S4 regulator and an adjustable regulator to see how much controlability we can achieve on an 82 928 and give the results.

Mk

> In looking in the manuals, the fuel regulators on the 84s and 82s are the
> same part number as the S4s (0280 160 215) (and 85-86) can anyone confirm?
> Also, the fuel pump seems to be the same part numbers in the manual. (ie
> 0580 464 017)
>
> If this is the case, it would make no sense to put a S4 fuel regulator in
> place of the Stock 84 regulator on one side to bump fule pressure and use
> only one rising rate regulator. (to save costs) Ive also heard that a
> damper used in place of one regulator can do the trick. sounds weird, as
> the fuel path would be going through it in the reverse direction for its
> design. dont know enough about "dampers" to understand this idea.
>
> any help . Im trying to help scot get his fuel pressure up, and we just
> installed one rising rate regulator and are debating on what to do for the
> other side (the AFM cars have two regulators and one damper stock)
>
> MK

Weissach1982

Well I figured out my problem to my above post with the help of Mark. It was a major vaccum leak around one the intake manifold "runner'' gaskets, caused major backfiring ''popping'' and the AFM door slamming against the inside. By doing what mark mentioned about holding the AFM door open to a certain RPM, everything smoothed out until I let it almost closed and then the car died. I changed spark plugs from Bosch Supers to Bosch Platinums..the supers were fouled. But everyone keep in mind to put new gaskets on those Euro parts, that would be the safe way to do it, and taking off those runners and plenum is a chore..but i've done taken them of twice now...and going to put them back on when i get new gaskets. The only thing that I thought was cool when my car was not running right and everything was backfiring was the foot long flames that were shooting out my exhaust pipe. Sounded like a pro mod 928 with open headers and running on pure N20. Kinda cool, but glad its going to get fixed. Just wanted to inform everyone. Plus I think i'm going to go with the idea of the clamping off that return line on the passenger side fuel regulator...i'll wait and see how things turn out for mark and that 82 car hes working on.
Cory J.

Jon F

I replaced all of the runner gaskets on mine as well. They were very hard and brittle, and some of them got stuck and tore.

Weissach1982

My gaskets should be here tomorrow morning..so I hope to have a running vehicle by tomorrow night. Speaking of the gaskets, what is the Torque Specs on the intake manifold "runner'' bolts. I have crappy old manuals and they don't mention anything about the torque specs on the Runner Bolts. Anybody who can help?
Thanks,
Cory J.

Jon F

Updates anyone?

mark kibort

becareful about clamping off the one return line. It will certainly raise perssure, but that line is a non pressure return line. by clamping it off, it will become subjected to pressure. this could be a problem I would find a way to seal the outlet, and then attach the stock return line. Im sure there is a right way to do this , and it will work.
we will do the clamp technique on the dyno just to see the effect, not for a perminant fix

MK

toofast928

Working on the front suspension. Won't turn the key till March.
I have ported the USA "U", cleaned the runners and Euro TB. Replaced the intake gaskets and vaccum hoses. Still need to pick up a AFPR and send the injectors for cleaning. I plan to use an oil catch tank off the oil seperator. My blow-by is small few drops of oil in the intake but still no oil should be ingested.
While the hood is off, disassembled and cleaned the blower motor, very easy.