924Board.org

bryanc · Joined: 27 Feb 2003 Posts: 233 Location: San Antonio, Texas

Since day one (of getting my 924) I have questioned the fuel pressure. I am going to get a fuel pressure guage (diagnostic type) and I know it has to go to at least 100lbs. Anything else I need to know? I remember seeing a CIS specific fuel pressure guage. Is this necessary? I am looking at a SUN guage.
How many of you have found problems with fuel pressure?
_________________
'84 944
I'd rather have a bottle in front a' me than a frontal lobotomy
Tom Waits

Roger · Joined: 06 Jan 2003 Posts: 1235 Location: Cordova, TN

The CIS guage is not necessary it just comes with all the fittings you need. The Sun guage will work but you will have to cobble the fittings yourself. You need to measure the system pressure vs the control pressure, and it will also be helpfull to see how long the pressure holds.
_________________
1981 924 NA

Some people are like Slinkies. Not really good for anything, but you
still can't help but smile when you see one tumble down the stairs.

924martinirossi · Posted: Wed May 07, 2003 2:08 pm Post subject:

http://bmpdesign.com/bmw/parts/catalog/o2_11b.shtml

Go down the page about halfway and buy this one. I bought one last Nov. and it is great quality with all the fittings you need.

Michael

Vaughn Scott has the same also.

924RACR · Posted: Wed May 07, 2003 10:16 pm Post subject:

Yes, I have it, kick myself for never having bought it sooner. You also need, in addition to the fittings, a valve plumbed in to properly measure all pressures (with CIS). Just buy the right one.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

bryanc · Joined: 27 Feb 2003 Posts: 233 Location: San Antonio, Texas

Is the '82 924 n/a a J or L jetronic system?
Don't guess. I'm going to spend $60.00 on the answer.
_________________
'84 944
I'd rather have a bottle in front a' me than a frontal lobotomy
Tom Waits

924RACR · Posted: Tue May 13, 2003 1:06 am Post subject:

Neither. It's a K-Jet.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

bryanc · Joined: 27 Feb 2003 Posts: 233 Location: San Antonio, Texas

The choices on the page sugested for the presure testers are K or L jetronic.
I think I remember somewherer in the Haynes text it noting that although the system is called jetronic it does not mean it is an electronic F.I. system.
The Haynes manual calls the CIS system Lambda injection for my year 924. I just wanted to confirm that the lambda jetronic is what the guage supplier calls an L jetronic.
Look at the page from 924martinirossi if I am not clear on what I am asking.
_________________
'84 944
I'd rather have a bottle in front a' me than a frontal lobotomy
Tom Waits

Roger · Joined: 06 Jan 2003 Posts: 1235 Location: Cordova, TN

CIS stands for constant injection system I think. All CIS systems are mechanical injection not EFI. The Bosch CIS tester will work here is one

http://www.autopart.com/Tools/file/part89.htm
_________________
1981 924 NA

Some people are like Slinkies. Not really good for anything, but you
still can't help but smile when you see one tumble down the stairs.

bryanc · Joined: 27 Feb 2003 Posts: 233 Location: San Antonio, Texas

I give up.
I'll just borrow my brothers Snap On fuel pressure tester and try to find fittings to adapt.
I'll just spend the money on a stereo and speakers the PO removed.

Does anyone have the manual on troubleshooting Bosh CIS systems mentioned in the ad for the L jetronic presure guage. I will have to assume the L jetronic system is the same as the Lambda system refered to on page 97 of the Haynes. I know it says (section 34 paragraph 1) it is basically the same as the K-jetronic system but that is why they have another section labled "Lambda injection system", because it has different test values and I would assume different fittings.
If you can steer me to a the text of the troubleshooting manual (TIFF, PDF or other) let me know.
Thanks for the help

_________________
'84 944
I'd rather have a bottle in front a' me than a frontal lobotomy
Tom Waits

924martinirossi · Posted: Tue May 13, 2003 3:37 pm Post subject:

I'll see about scanning some pages to send you. Remind me thr email in the morning.

Michael

924RACR · Posted: Tue May 13, 2003 10:35 pm Post subject:

No, L-Jet is EFI, same as used on the 944/924S. The 924 and 931 use K-Jet, which is CIS. Some CIS systems use "lambda" feedback from an O2 sensor. You still need a tester for CIS aka K-Jet.

EFI: electronic fuel injection; fuel is metered by the injectors, pulsed injection
CIS: Continuous Injection System; fuel is metered by the fuel distributor, and is continuously pumped/injected into the intake, not pulsed. Operates at a much higher pressure than EFI.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Roger · Joined: 06 Jan 2003 Posts: 1235 Location: Cordova, TN

I have a book on CIS systems but its general because it covers CIS for all the models it was used on. Everything from VW to Saab. You are pretty well stuck with the Haynes or you could buy the factory manual. I would send you some info just give me your email address.
_________________
1981 924 NA

Some people are like Slinkies. Not really good for anything, but you
still can't help but smile when you see one tumble down the stairs.