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1976 924

vitesse

Active member
A little catch up on where we are with my friends car:-
After many hours over many months -I finally persuaded him that we couldn't get any farther in making it both reliable & stable without a fuel pressure test rig so a gauge set was bought off Ebay & we visited a local hydraulics stockist who made up the 2 appropriate connection hoses & supplied a T piece connector plus ball valve.

Connected it all up as required to find that system pressure was off the gauge ie over 7.5 bar -nothing I could do by tapping the relief valve area of the fuel distributor would alter things so removed the necessary fuel fittings & the spring retention plug-valve firmly stuck in place hard against the inside port.It was eventually removed by a lot of fiddling ,releasing agent & a suitably sized screwdriver blade which fitted inside the cylindrical valve plunger.

This week after my friend had cleaned up everything sourced a new tiny O ring for the valve,we re-assembled it all & tested again & now get 4.8 bar for system pressure (should be 5.2bar).When the ball valve is opened it drops initially but returns to the same reading(should be 3.2 bar)
This is Cold with Bosch plugs removed & using a relay bi-pass lead with switch.

So hunt is on for a Warm up (or Control pressure ) unit-before we tackle the lower pressure figure.
We have a spare fuel distributor but at present can't extract the shims from the retaining nut ( I suppose if all else fails we could drill a hole through it to poke them out & use whatever is fitted therein to increase the system pressure reading.

However ,did start the engine (with bi-pass still in place) & started easily & idled & allowed reving up so a big improvement.

Anyone got a warm -up unit for sale at reasonable price?

 
That car is a real labour of love for you! The pressure test rig is, I think, an essential bit of kit for setting up the system properly. The other important thing to check with the rig is that the fuel pressure doesn't bleed off too quickly when the engine is turned off, to avoid hot start problems - usually indicates a faulty accumulator.

I'm fairly sure I've got at least one spare Control Pressure Regulator in my spares box though it may need re-commissioning - PM me if you are interested. I'll check in the garage tomorrow.
Cheers
 
Glad you got the pressure gauge as without these you're setting up a 924 blindly at best. If the pressure relief valve was stuck solid I would imagine the plunger is also sticking so would be worth getting your hand in the airbox and pushing the plunger up to check is moves up and down freely. How long was the car sat for?

The warm up regulators can be stripped quite easily, cleaned & rebuilt then set up using the pressure gauges. There are loads of guides on line as its the same for mk1 & 2 golfs plus Mercedes.

Sounds as though you're on the right tracks - keep us updated
 
Thanks for the replies ,Vince & Russ-been away at our cottage on the IOM no wi-fi so only seen them today.

The central fuel regulating pin is quite free-it's just that until now with no pressure testing kit,I hadn't known & had no reason to investigate the relief valve although have suspected the fuel pressure was a problem.

Keep missing weeks here & there because of families/holidays but since that post ,my friend has sourced a fuel regulator,then I've been away & now he's away at their Cyprus house until 2nd week Sept.
I have had a look inside the regulator but that was 2/3 years ago & hadn't sussed what was adjustable then so took the view to get a S/H replacement
as that is what the Bosch book says what would be required(replacement not S/H).

If necessary can fit the plug with the stuck in shim(s) & use the loose shims we have to see if the system pressure can be adjusted to 5.1/5,2 bar-my other idea would be to make some from feeler gauges using a leather hole punch.

One of these days I'll know what I'm talking about[8|][&o].
Vince thanks for the offer-since Mikes now got 1,we'll try that 1st.
 
Further update:-S/H control pressure regulator fitted-system pressure no higher now than 4.7-but control pressure still high but better at 3.8 ( gauge reading now drops when you open the test valve) & residual pressure reasonable at 3.
Reset idle speed to 800rpm then mixture to the best I could get at 13.4 ( couldn't get it upto the recommended 14 or so).
Then decided to investigate nasty exhaust rattle -removed a hanging clamp just before the 1st silencer which was just loose around the transition bend after the down pipes -success.
Then had to replace the drivers seatbelt receptor-someone had replaced the seatbelt but not its matching receptor.
Fingers crossed -we went for its 1st drive round the block & all good -not perfect but given the circumstances welcome-nothing seized up-no drips or fluid losses but Mike thought the brakes were awful-not surprising really-they've not been used for 20 yrs or so & so after possibly 3/4 hrs running time the engine was still stable returning to correct idle so a reasonable days work & result.
Frankly ,I'm not sure how critical the fuel pressure figures are in reality but Mikes back off to Cyprus on Tuesday for 4 weeks so it will have to wait till his return.
I am tempted to use some shims from the spare pressure relief valve to see if we can get the system pressure upto the listed 5-5.1 -tempted to make the removed WUV adjustable if all seems ok internally ( as Google search) because may then allow mixture setting to nearer the stoichimetric figure of 14 .2.

Fortunately I don't yet have nightmares about Bosch CIS systems on Porsche 924's but have learnt a lot on my journey from fuse boards ,relays,headlamp motors,rear windscreen wiper motors,switchgear,water pumps ,hoses etc.
Thanks for your interest & supporting comments.
 
Ken Mills Injection ... http://www.kmipetrolinjection.co.uk/ ... are a great source of information and parts if required. They have supplied and modified parts for me (VW Golfs Mk1 / Mk2) in the past, including an externally adjustable warm up regulator (WUR / WUV).

I have some surplus Golf KJet spares if of use to you, the Bosch on line catalogue is a useful reference for make / model part applications.

Keep up the good work ...




 
Thanks Andrew-did know about KMI & have suggested to my friend that we could have moved forward quicker if we were to get a recon fuel distributor/ WUV from them but I don't think he wanted to spend that much money -he could be interested in the parts -any chance of a brief list with prices please & Ill forward it to Mike.

Thanks
 
I`ll get a parts list together in the next week, not yet sure what would be compatible ...
No money required for the old / used items.

What engine / fuel system in the 924 ?
 
That's very generous of you ,Andrew-car is a 2 litre 1976 model with points/capacitor ignition so had the black cast iron Bosch fuel distributor with braided fuel lines to the injectors & no lambda sensor.

After I successfully rebuilt this distributor head,I then found out that the fuel tank was full of detritus which had got to the distributor so I have replaced the distributor head with the next version which has steel fuel lines-this doesn't have the "push valve".
Will pay any carriage of course.thanks.

Colin.
 
Colin ... used KJet parts list (Bosch - VW / Audi tagged).


Airbox
VW / Audi - 027 133 837 Q

Air Flow Meter
Bosch - 0 438 120 195
VW / Audi - 027 133 353

Fuel Distributor
Bosch - 0 438 100 140

...

Airbox
VW / Audi - 067 133 837 K

Air Flow Meter
Bosch - 0 438 120 189
VW / Audi - 049 133 353 AA

Air Flow Meter ... Outlet Rubber Boot
VW / Audi - 067 133 357 CR

Fuel Distributor
Bosch - 0 438 100 100

Set of braided hoses ... from fuel distributor

Four with injectors
One for cold start valve

...

Fuel Accumulator (from Mk1 Golf GTI 1600)
Bosch - 0 438 170 027

Fuel Filter
MANN - WK 618 ... would not use the filter but comes with inlet and outlet hoses

Warm Up Regulator (c/w two braided hoses)
Bosch - 0 438 140 118
VW / Audi - 026 133 403

...

Rubber Hose ... fits both Airboxes
VW / Audi - 067 103 2210
~ 30cm - OD = 24mm - ID = 16mm


I have no history of most of these parts, I purchased them to strip - investigate - learn when running modified Golf KJet engines.
The fuel distributors have been removed from the Air Flow Meters.

If interested, I can email pictures of all items.




 
Thank you,Andrew-jpegs would be great-however,early tomorrow am ,we are off up to Whalton ,Northumberland on Grandparenting duties & not back until late Monday.I won't ,therefore be able check through parts nos etc until next week and don't want put to you to more trouble than necessary.
As you are a guest of the club,I don't think I can PM you my email address as I don't wish to publish it on here.

Colin
 
Just sent you my email ... will get the `box brownie` out and send to your reply.

No trouble, in your own time.
 
I've been checking part nos -however I do know I want the braided hoses & injectors,Martin,sorry.
Will compile my list tonight & post it here , Andrew.

Colin
 
Andrew_CS said:
Colin ... used KJet parts list (Bosch - VW / Audi tagged).


Airbox
VW / Audi - 027 133 837 Q

Air Flow Meter
Bosch - 0 438 120 195 *****
VW / Audi - 027 133 353

Fuel Distributor
Bosch - 0 438 100 140 ****

...

Airbox
VW / Audi - 067 133 837 K

Air Flow Meter
Bosch - 0 438 120 189 ****
VW / Audi - 049 133 353 AA

Air Flow Meter ... Outlet Rubber Boot
VW / Audi - 067 133 357 CR *****

Fuel Distributor
Bosch - 0 438 100 100 ****

Set of braided hoses ... from fuel distributor

Four with injectors ****
One for cold start valve ****

...

Fuel Accumulator (from Mk1 Golf GTI 1600)
Bosch - 0 438 170 027 ****

Fuel Filter
MANN - WK 618 ... would not use the filter but comes with inlet and outlet hoses

Warm Up Regulator (c/w two braided hoses)
Bosch - 0 438 140 118 ****
VW / Audi - 026 133 403

...

Rubber Hose ... fits both Airboxes
VW / Audi - 067 103 2210
~ 30cm - OD = 24mm - ID = 16mm


I have no history of most of these parts, I purchased them to strip - investigate - learn when running modified Golf KJet engines.
The fuel distributors have been removed from the Air Flow Meters.

If interested, I can email pictures of all items.



Andrew,
I have annotated those items I would like with -****----despite your generous offer ,there is no point me having the other items just for the sake of it & which I can't tell whether they would work in our case.

Please let me have the cost of P & P etc & I can let you have a BACS transfer prior to carriage.

Regards

Colin.
 
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Have managed in some awkward way to upload some images from Imagur-sorry for the dull one.
This Thursday ready to try extra shim in the control pressure valve cap when Mike explained that the speedo didn't work when we drove round the block 5 weeks ago ,so spent all morning getting the speedo out of binnacle
until cable restricted further progress.Turned attention to nearside front wheel,removed it ,then the speedo cable retention circlip,dust cap to find that the cable end fell out-sheared at the fitting.

After lunch fitted extra shim from a spare fuel distributor switched on pump and gauge showed 5.1/5.2 bar-started engine which fired immediately & settled down to idle so seems a success.
Ran out of time so next Thursday hopefully the new speedo cable will be with us & will fit it (will check that speedo isn't jammed 1st).Then reset mixture again.

Hopefully system will now be stable & we can move on to fit perhaps the better fuel accumulator & injectors ( once ultrasonically cleaned in Mike's unit) that Andrew has offered.
 
Further update:-finished installation of new speedo cable today-what a pig of a job I found it mainly because of getting the speedo out as well as moving the whole binnacle clear with it to get access to the cable fixing ,removing steering wheel,switch unit,all requiring in my case removing the driver's seat,so I could lie down on my back in the empty seatwell with feet high up the rear seat to get to the 2 wiring plugs,followed by threading the new cable through the rubber grommet & through the bulkhead hole which is conveniently [:mad:]placed high up in the passenger footwell before needing to extend all the wiring for the speedo because they were too short for replacement (impossible to access from the rear).
Anyway all was back together for lunch-(thank goodness for my daily dose of 1000mg cod liver oil/vitamin tablet)-certainly helps with the bending,twisting& contortions required.

Spent afternoon setting idle speed & rechecking idle mixture-still can't get air/fuel ratio better than 13.5-13.6 but idle now 850rpm & engine very stable with good pickup.Left 'til next week for further test driving.(possibly also to try & bed brakes in better) -system pressure also stable at 5.2 bar[:)]

Future possible improvements revolve around replacing the now cleaned injectors,WUR & accumulator(from Andrew).
 
Great work [:)]

Good to hear its all coming along nicely and also nice to see an older 924 kept on the road. Getting the speedo out is really awkward but getting the cable re-attached is a pig of a job so well done!

Look forward to the next update
 
[:)]


Look forward to the next update

[/quote]


So here is a small update:-have spent recent weeks generally tidying up bits & pieces allowing for Xmas /New Year breaks etc. such as,drilling small holes in the grille top surround so that I could use small cable ties to attach the section of lighting loom which crosses here right to left-sorting out the handbrake warning light in the instrument panel(like a wheel on Mike's car ) but wondering why the rectangular lamp on the central dash still lit up until I put my reading glasses on & realised it was brake warning lamp that was staying lit.Wondered whether the two lamps had their wiring connections reversed until the brain got into gear & I checked the Master cylinder-doh-oil quite low ,so quick top up & lamp extinguished.
That left the top handbrake lamp -flipped off the red cover took out the pigmy bulb which tested OK,re-aligned the bulb contact wires ,re-inserted bulb & -bingo -now working .
Attached driver's door mirror but no passenger mirror as yet -Mike is after 1 at the sensible price-anyone got 1?-please.
At home ,I stripped the original WUR & the identical part numbered version Andrew kindly offered to find the setting of the bimetallic strip ,in my case the dimensions from the casing joint to the top of the arm where the operating pin passes through a slot to the diaphragm valve were different by 2mm.So yesterday fitted the 1 from Andrew having checked out "hot" operation using my battery charger.
Engine started OK & settled down to sensible idle without "fluffing" when attempting to drive it-previously it needed to be warmed up quite a lot.Had to reset both idle & mixture again -previous settings were now miles out but reached an acceptable compromise-still can't get it further up the "lean " scale but within accepted limits.

Also tidied up some earth wires in the boot & some disconnected radio speaker connections-fitted window winders & left Mike to find the door seals & fit them.

Next week ,hopefully will give it a longer drive workout.

Further pictures attached .(Well I thought they were but method used previously won't work tonight)
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