CIS fuel pump
11-13-2013, 08:48 PM
#16
Three Wheelin'
Docmirror, you are trying to confuse me here. What do you mean by AFC ? AFAIK, there were only 3 injections systems used on 928s - CIS (aka K-jet), L and LH-jet. Is AFC another name (being Air Flow Controlled ?) for CIS/K-jet ? My info shows L-jet ran pressures around 40psi, and LH maybe a little higher (45?), but CIS runs 65-75 system pressure.
For FBIII, all the systems are controlled by a pressure regulator - in CIS its inside the fuel distributor; in L and LH its done by external regulators that are modulated by engine vacuum, to reduce pressure at high vacuum. The only other valve I know of is the check valve at the pump, whose only job is to STOP pressure dropping as the engine cools.
jp 83 Euro S AT 55k
For FBIII, all the systems are controlled by a pressure regulator - in CIS its inside the fuel distributor; in L and LH its done by external regulators that are modulated by engine vacuum, to reduce pressure at high vacuum. The only other valve I know of is the check valve at the pump, whose only job is to STOP pressure dropping as the engine cools.
jp 83 Euro S AT 55k
11-13-2013, 08:58 PM
#17
Advanced
Thread Starter
You guys are all a tremendous source of great feedback as well as fun reading. I would like to take a second here to thank Roger for helping me to make sense of it all and for helping me to procure all of the parts I need to put together a CIS system that I feel very confident will serve me well. Thanks again to all.
Joe
Joe
11-13-2013, 09:13 PM
#18
Rennlist Member
OK, rocket motor pumps are different from what we speak of here. Why speak of 'upper end pressure available' , ie a limiting condition, when all I am contending is that an L or LH pump can supply enough pressure and flow to satisfy CIS demands, based on personal experiences.
Anyway, if the OP is fitting all the correct parts for CIS, the question is moot, by the look of it.
jp 83 Euro S AT 55k
Anyway, if the OP is fitting all the correct parts for CIS, the question is moot, by the look of it.
jp 83 Euro S AT 55k
11-13-2013, 09:30 PM
#19
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Just for the interest content - PET shows an in tank pump was fitted for the Australian and Japanese markets only 80 to 83 4.7L 16v 300HP engines. Also 84 to 86 310HP 16v engines with twin dizzy.
Certainly on Australian delivered cars I have found this to be the case.
Certainly on Australian delivered cars I have found this to be the case.
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
11-13-2013, 09:53 PM
#20
Rennlist Member
My car is a C16, UK delivered car, so no in-tank pump. The fact that it survived that way in Saudi from about 1990 (when it was shipped to Saudi from UK) to my exporting it to OZ in 2002 shows how little the in-tank pump was needed, at least in this case.
jp 83 Euro S AT 55k
jp 83 Euro S AT 55k