2dogsjohn

hi guys, ive got my hands on CIS fuel test gauge and i am really keen to see just what i have got. car is 82 euro S . the runs pretty good but like any car could run better and wont do any harm to test everything anyway.
having read tons of stuff i am reasonably confident in what to test and how but really struggling to get my hands on some real figures of what i should have and not just what other folks have got .
ie system pressure
cold control pressure
warm control pressure etc
times temperatures and so on
I'm living in france and dont know how to get my hands on some wsm's or indeed which ones to look for. any ideas anyone. thanks

ammonman

Contact Roger Tyson at 928sRUs. He sells the CD set of collected WSM's and technical books assembled by Jim Morehouse. This will have all the info you need and is one of the best investments you can make for your 928.

Mike

Jadz928

CIS quick-reference:
http://928classics.com/4/post/2014/0...ide-78-79.html

2dogsjohn

thanks i found this link before but it is for a 78/79 car with 4.5 engine. anyone know the numbers for a 82 car. looked all over the internet , cant find anything.

jpitman2

Mine is an 83 Euro, I dont think much different from yours in CIS.
I used Watson's book on Bosch Injection systems as it gives trioubleshooting notes.
My figures - System=75psi, cold control varies with temp, but can be as low as 15psi - if you really need it I can look up psi at temp - only real test is does it start and run OK cold; hot control is the important one - 41-46psi on mine drives REALLY WELL. You also need to get the delivery rate tested - 1360ml/30 secs. The more you run CIS the better it gets.
good luck. Planning on Paris in June!
We are Charlie!
jp 83 Euro S AT 56k

Jadz928

The numbers are the same for 4.7L RoW
For warm control pressure, they should fall on the low side of the 41-46psi spec.

I will update the CIS quick reference guide to include all.

2dogsjohn

thanks for that guys ,i'll hook it up later on and let you know what i get.

2dogsjohn

ok so now i'm really confused, i connected the guage in the curcuit and 99% sure ive done it right. rigged up a toggle switch for the pump and unhooked the wur. then it gets interesting toggle the switch to run the pump ,valve open and zero cold control even after 1 minute . close the valve and 45/50 psi system pressure .then open the valve and pressure stays the same. if i do the same with the engine running ,same thing zero cold cp but when i close the valve for sp the engine actually runs better and speeds up
(the opposite should happen. shouldn't it? ).
so where do i start now ;is the FP shot for a start or is it more likely a blocage. i know that the accumulator is knackerd it has the third connection on the top for a vent that has been welded shut. obviosly because its full of fuel if you undo it. how likely is this to figure in the problem as i dont really get any hot start issues.
so calling all jetronic gurus as i could use some help. thanks

jpitman2

You must have the gauge plumbed wrong. Here is my sequence - remove inlet line INTO WUR and connect to gauge leg with open/close tap BEFORE the gauge; connect other gauge leg into the WUR connection that is now exposed. On my car the first connection is a PITA as the inlet tube points downwards and its difficult to get the gauge hose to line up properly. If your engine runs it would seem the WUR is doing some work for you.
jp 83 Euro S AT 56k

Jadz928

^^^ what JP said.

Fuel feed come from top of fuel dist. Gauge needs to be on feed side, then valve, then fuel return.

2dogsjohn

exactly what ive got. believe me i've checked ,triple checked and compared it to every photo on the internet. i'm sure its right ie from the U shape metal inlet pipe into non guage side then meter then valve then into orafice U pipe was connected to ( wur inlet).
I'm going to see if maybe the guage is at fault i bought it in germany but it looks like one of chinas finest.if you know what i mean.secondly going to check pressure at inlet to FD to eliminate pump or blocage theory.
tell me if i'm right or wrong so far

2dogsjohn

so spent the day on the car and eventually found the source of the dodgy readings. the guage is guess what CRAP and a lesson for us all in buying anything that even looks like its been anywhere near china. non of the unions connect together properly and the bayonet union between the guage line and the T completely seals itself in both directions so pressure can't really rise nor go back down.anyway after stripping the innards out of it i got it to work sort of.
anyway got some initial readings so here goes
cold CP 8psi @ 48 f
warm CP 56 psi
system P 80 psi
then did leak down but a bit wierd so from 56 warm CP ;stop pump and instantly hits 40 psi
after 15 mins 35 psi
after 20 mins 32 psi
after 25 mins 26 psi
after 30 mins 8 psi
changed the shims to get control down to 74 psi and going to tackle the wur tomorrow. but please give me your advice

Jadz928

Cold control is low (Don't adjust until warm control is in spec)
Warm conrol is high, check for blockage causing pressure rise at WUR (or further upstream/downstream)
Leakdown reads good for now.

jpitman2

To me actual cold control figure is moot - all that counts is reliable cold starting and warm up.
The 56psi warm (do you mean WARM, or fully hot through?) is too high - when mine got to 60psi it was difficult to get more than very slow acceleration to 15mph. If you can load the gas with a cleaning oil (Techron, Berryman's), you could try bridging the fuel pump relay and letting gas circulate for as long as possible to try to clean crud out of the WUR. Failing that, remove the WUR and try to blow a solvent like brake clean through it in both directions. If it has a brass filter in the inlet, see if you can remove it without destroying it - best way to remove crud from these IMHO is to burn it off with a lighter.
My earlier msg about connecting the gauge set was WRONG ...sorry. Glad to see you sorted it out!
jp 83 Euro S AT 56k

2dogsjohn

ok so another day of testing and tampering and got almost all the readings spot on. leak down still not sure about . starting leak down test from warm control reading isnt too bad, but from system pressure it instantly drops from 74 to about 40 ish then slows right down. gonna take another look at check valve and replace anyway.
anyway tonights question . do you think ultimately the most accurate reading are taken with just the pump running or with engine running. always seems to be a slight difference , perhaps battery power hence pump speed.
rebuilt wur today with a couple of mods and seems ok, final testing tomorrow then will post results. thoughts on leakdown appreciated