| View previous topic :: View next topic |
| Author |
Message |
Dutch924-racer
Joined: 23 Jul 2007
Posts: 1081
Location: The Netherlands
|
 Posted: Fri Mar 04, 2011 4:05 am Post subject: Home made cis tester ??? |
 |
|
Has somebody made a cis tester ? What parst do I need ?
_________________
937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller |
|
| Back to top |
|
 |
Harm
Joined: 02 Apr 2009
Posts: 1378
Location: Holland
|
| Posted: Fri Mar 04, 2011 6:24 pm Post subject: Re: Home made cis tester ??? |
|
|
I dunno…
This may not be close to a CIS tester but it's able to give you a reading on the fuel pressure on board, even during action.
The solution is nothing fancy and it's been around quite a while (Picture: Turbo prototype) but doesn't get much attention somehow.
^Disclaimer: I have no idea if that does what or anything at all… 
I actually haven't installed the setup I have in mind so its just the idea's basics as I've put it on my ever expanding To-do list… 
As a main ingrediant you'll need an Oil Pressure Sender like you'll find on the back of the engines head. Something some of us keep in the spares drawer already. You will need to put that into the fuel support lines somewhere upfront, preverably between the Fuel Distributor out, to the WUR (aka Control Pressure Regulator).
My car is equiped with the HSV(-braket) so I guess I can place the sender unit in/up/around there; Haven't looked into that part yet. And I would give it an extra strap to ensure ground, preferibly under the dash but could be anywhere on the chassis of course: But NOT the HSV ground wire!
Hook up a wire on the Senders G-side and get this into the cabin.
Now the fun part; The gauge is already in use by the actual Oil Pressure Sender sitting on the back of the head, so you'll need a switch instead of another gauge… Preferably a side mirror control switch as OEM part? That will blend in nicely next to the astray, huh. One wire (feed) in from the gauge; two wires out to the pressure senders, one wire each. Done.
— The Oil Pressure Gauge reads the engine oil pressure;
— flip switch you do;
— The Oil Pressure Gauge reads the fuel pressure.
That's the basic idea. It might not be a CIS tester but it will give you an idea on fuel pressure happening.
HTH
Regards, Harm.
_________________
Porsche 924 NA 1982 LY7A/A3A3 _ Greater driving pleasure never harmed anyone. |
|
| Back to top |
|
|
Rasta Monsta
Joined: 12 Jul 2006
Posts: 11733
Location: PacNW
|
| Posted: Sat Mar 05, 2011 1:15 am Post subject: |
|
|
Love the creative thinking, but I don't think it would be accurate enough. . .we're talking .1 BAR increments.
_________________
Toofah King Bad
- WeiBe (1987 924S 2.5t) - 931 S3
|
|
| Back to top |
|
|
fiat22turbo
Joined: 18 Jan 2006
Posts: 4040
Location: Portland, OR
|
| Posted: Sat Mar 05, 2011 4:55 am Post subject: |
|
|
.1 BAR = 1.45psi
Might be able to replace the clock with a more accurate gauge. Perhaps a digital one?
The sender itself should be accurate enough, but the gauge has a range it works in and usually is dampened to make it easier to read.
If you have a way to log the output of the analog signal, then you could forgo the gauge and merely log the data and tune by looking at the data or watching the live data feed.
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose) |
|
| Back to top |
|
|
Smoothie
Joined: 01 Jan 2003
Posts: 8032
Location: DE (the one near MD, PA, NJ)
|
| Posted: Sat Mar 05, 2011 5:09 am Post subject: |
|
|
_________________
"..it's made in Germany. You know the Germans always make good stuff."
'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox |
|
| Back to top |
|
|
Dutch924-racer
Joined: 23 Jul 2007
Posts: 1081
Location: The Netherlands
|
| Posted: Sat Mar 05, 2011 5:27 am Post subject: |
|
|
I assume a 0-7 bar gauge will be enough ?
_________________
937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller |
|
| Back to top |
|
|
El Chato
Joined: 22 Aug 2006
Posts: 205
Location: El Paso, TX
|
| Posted: Sat Mar 05, 2011 9:57 am Post subject: |
|
|
As far as testing, I have only place the injectors in graduated cilinders and pushed the the air meter and compared the total volume per minute and spray pattern, and onboard preasure gauges sounds mutch better specially if digitilize
_________________
1979 924 N/A, Snail Shell
1980 924 N/A
1976 924 N/A
It may be that your whole purpose in life is simply to serve as a warning to others.
Today's weirdness is tomorrow's reason why. |
|
| Back to top |
|
|
Dutch924-racer
Joined: 23 Jul 2007
Posts: 1081
Location: The Netherlands
|
|
| Back to top |
|
|
dpw928
Joined: 02 Nov 2002
Posts: 1860
Location: owasso, ok 74055
|
| Posted: Sun Mar 06, 2011 12:29 am Post subject: |
|
|
The pictured gauge doesn't have a valve that is required to measure systems pressure, which is half the equation in the correct operation of the CIS system. BTW system pressure is controlled internally by the relief valve and can't be measured at the CSV as was mentioned on Rennlist.
Dennis
_________________
81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black |
|
| Back to top |
|
|
Harm
Joined: 02 Apr 2009
Posts: 1378
Location: Holland
|
| Posted: Tue Mar 08, 2011 11:42 pm Post subject: Re: Home made cis tester ??? |
|
|
| Rasta Monsta wrote: | | Love the creative thinking, but I don't think it would be accurate enough. . .we're talking .1 BAR increments. |
Thanks, but the main idea of this tool has been around for a long time (the 924 Turbo prototype for one), on other boards and other cars.
I'm not suggesting it is a replacement for the CIS test(er) since it will not be accurate enough. It will still give you an insight on the WUR/fuel pumps health and diagnose problems in the CIS range you've come across and/or want to monitor and avoid. Using the Oil Pressure Gauge for dual purpose does insist that your electrics are in good shape though; A buincy needle wouldn't be helpfull. Adding this setup to a half resurrected engine with no history whatsoever wouldn't be helpfull either since you wouldn't know what to compare the given readings too.
When added to a healthy engine that just passed the CIS test succesfully, you'll be able to monitor more up close what the state of the CIS is in from there on; for example its behavour during startup (WUR) and hot start (HSV) …well, just satisfying my curiosity in general 
Being the fun car for daily use as these cars are intended
you want to spend as little time possible under the hood
once she's back in the sun, out on the road 
Looking into the HSV bracket that holds the line out from the Fuel Distributor towards the WUR; Both these lines bolt up on the top of the bracket, held down by a banjo bolt with the appropriate holes that establish the connection in that line. Adding a third connection between these two that would hold the former Oil Pressure Sender, and using a longer banjo bolt could do the trick I guess; You would then be able to monitor the fuel pressure to the WUR. …sounds pretty easy really.
| Code: | [———] Banjo Bolt / Hollow Screw
H—H <<< Line out from Fuel Dist.
>H—H——Fuel Pressure Sender<
H—H >>> Line towards WUR
[———] HSV bracket
[ ]
[_O_] > Fuel return line connection
[ ]
[ ] HSV valve
[___]
H Wires
|
I'm keeping an eye out on a longer hollow screw with three holes, and something that will fit this new banjo bolt and is able to carry the Fuel Pressure Sensor in that place.
Does anyone have online directions (apart from the local Hydraulics workshop)?
Cheers, Harm.
_________________
Porsche 924 NA 1982 LY7A/A3A3 _ Greater driving pleasure never harmed anyone. |
|
| Back to top |
|
|
Rasta Monsta
Joined: 12 Jul 2006
Posts: 11733
Location: PacNW
|
| Posted: Wed Mar 09, 2011 1:13 am Post subject: |
|
|
The valve isn't technically necessary. . .just for the convenience of hooking up the tool one time to test both system and control pressures.
_________________
Toofah King Bad
- WeiBe (1987 924S 2.5t) - 931 S3
|
|
| Back to top |
|
|
Joes924Racer
Joined: 03 Nov 2002
Posts: 11964
Location: Oregon, Denver Colorado native!
|
| Posted: Wed Mar 09, 2011 5:00 am Post subject: |
|
|
Knowing whats first is good ... to know sys. press. For starters you can shim the spring to raise it. pump pressure closer to home is good -know too.
Its not being accurate enough is a down side. For me monitoring sys pressures from differnt locals would be awesome. Yea kind of like doing
the ouput tests of the pump line, injectors & CSV. Monitoring
them in action full time even better.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo. |
|
| Back to top |
|
|
El Chato
Joined: 22 Aug 2006
Posts: 205
Location: El Paso, TX
|
| Posted: Wed Mar 09, 2011 10:00 am Post subject: |
|
|
Kind of re minds me of the 911 dash I've seen a couple of times just full of gauges, it be cool to have them going berserks at an inspection
_________________
1979 924 N/A, Snail Shell
1980 924 N/A
1976 924 N/A
It may be that your whole purpose in life is simply to serve as a warning to others.
Today's weirdness is tomorrow's reason why. |
|
| Back to top |
|
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
924 FAQ (Technical)
