Rich9928p

Also be aware that there IS a difference in the wiring at the engine between CIS and L-Jet. I convirted a later style engine to fit into my '79 track car from L-Jet to CIS and had to make changes due to differences in temperature sensors etc. It IS NOT JUST A PLUG AND PLAY swap.

If who ever did the change on this car did it by swapping engines, everything on the engine will have to be changed (as Quick Carl has said). Have you checked the engine number, if it IS NOT 28/01, 2, 3 ,4, 9 or 10, it wasn't built with CIS. The US L-Jet motor would be 28/10 or 28/11.

I also recall that the fuel line routing is very different between the CIS and L-Jet. For CIS fuel lines, the line comes in at the passenger side of the engine up top and goes back to the fuel distributor. For L-Jet, it comes in from the fire wall.

It wasn't so bad for me because I had the old CIS engine sitting next to the L-Jet engine and I just did a part for part swap. If you're doing this cold (having no understanding of either CIS or L-JET) you will be fighting many many problems.

My suggestion is to find someone with an L-Jet 928 and do a comparison of what was done to your 928. If it was a complete swap you'd be better staying with L-Jet and trying to figure out what it takes to fix the problems.

mulik51

Hey, I checked the number of the engine, it is 28/M03. So ti is 1979 engine. I kind of understand the CIS and L-Jet(now), but I never did see it on 928. I have one question, if I will change plenums, will I need the new gaskets?

Thanks,

Klim

Carl Fausett

Kim,

Your motor is a CIS motor, 4.5L, meant for K-Jetronic (CIS) and at 8.5:1 Comp ratio - perfect for supercharging.

Yep, you should replace those 8 intake gaskets, they are about $2 ea.

2V4V

Actually, he could have left it in place and functional. Pressure/volume from the pump being too high is never really a problem as long as you have the correct regs and reflow capabilities.

In fact, using a CIS pump is an old upgrader's trick for hi-po V-8's.

Greg

mulik51

Cool, and it has just 15000 miles.

Thanks,

Klim

mulik51

Cool. I will chach that today, maybe I got lucky!

Thanks a lot,

Klim

mulik51

Hey, here is new information.There is no cover on the rear fender, and in that compartment there is fuel filter and some small thing(fuel accumulator?). There are two metal tubes coming into the compartment, but they have pieces of rubbere hose on them which are cut of from everything. One hose from fuel filter goes under the fuel tank(Second CIS fuel pump?), and other is going along the two metal "hoses". All three hoses(two metal and one rubber) come in the engine bay from right side. There metal tubes have pieces of rubber hose on them(they were cut), and rubber hose from fuel filter comes to the engine and goes to the pressure regulator.
So, I don't know how to react to this? Is it right?
And in the engine bay shold there be only metal tubes, or I can connect the fuel distributor by rubber hoses?

Thanks a lot,


Klim

Jim bailey - 928 International

Klim as I said .."the big problem is your car is a bastard , a hybrid , not CIS yet Not L-jet " Your most recent discovery of modified fuel lines just confirms the problems. Absolutely no one can tell you what you have or do not have on your car. That is what makes it virtually impossible to give you advice. Creative engineering is often used on 928s then the subsequent owners find that things do not work like they are supposed too , replacement parts do not fit . Perhaps someone near you with a CIS car and some knowledge of how it works could bring their car and park it beside yours then spend some time comparing. The only way to have everything work as designed is go back to CIS. Obviously it did run with L-jet but only with a rats nest of jumper wires and such on the board . What were you thinking when you pulled off all those wires that someone determined were needed just to make it run ? I am trying real hard to be sympathetic to your plight but your lack of understanding created the problem. You need a really big favor from a local 78-79 owner.

mulik51

Thanks Jim, nut I wanted to go to CIS anyway, and I am a lot better in understanding the flow of fuel and simple relays, then impulses from the ECU. I hate computers(that's why I bought 1979 car). You can disagree with me or think that I am stupid but this is just the way I am. I want to ask you, do you have the fuel distributor-to-injector line, fuel distributor-cold start valve lines, line by which fuel goes back to tank(from fuel distributor). I mean do you have them on 928Intl, becouse I looked and found a lot of Fuel Injector Lines without year or any othere identification on them.
Thanks a lot,

Klim

Carl Fausett

If I find anything else that I have that I kinow you need, I'll throw it in for you.
Here is a good schematic to give you and idea what you need. If you have the 8-volume manuals, you are all set.

Carl Fausett

forgot the picture...

Rich9928p

I don't think any of the CIS 928s had a closed loop lambda system, that was used by Mercedes and was called a KE-Jetronic system. So the diagram shows more than is in a CIS 928.

mulik51

Thanks. Yeah, I have different diagram, and it does not have ECU in it.

On my diagrams, I have solenoid valve in the fuel system and I have a lot of air stuff(throttle by-pass valve, booster valve(vacuum control), blowoff switch valve, check valve, suction ejection pump).

Can you tell me, are this necessary, and are they installed on L-Jet?

And this air stuf, what role does it play in CIS?
(I thought that CIS is like diesel engine, you have high pressure in the system, and injector is spring operated. When pressure in cylinder goes up, injector opens and fuel goes in. The amount of fuel dependes on the system pressure, which is controlled by pressure regulator, which is controlled by mixture control unit).
This is the simple "CIS" how I understand it, am I right? And one more practical question, CIS has only one fuel pump(which gives 80psi), right?

Thanks a lot,

Klim

Carl Fausett

Some of the 928 CIS systems have a single fuel pump and some have two pumps in series. They both produce the same pressure. The difference is volume, the single-pump systems doing about 1160 ML per Minute and the dual pump systems doing about 1320 ML per minute, if my memory is good ( I do not have the 8-volume manual set in front of me - but I know that actual numbers are in there.

mulik51

Great. So I will just take the L-Jet pump out and put a new one in. What about those air valves. Do I need them?

Jim, do you have the fuel lines on 928Intl?

Thanks,

Klim