CIS to CIS-E conversion

Whoa, that's getting me all the way into mid-80's technology!

The object: to convert my 1982 Coupe's engine management system from the almost-mechanical K-Jetronic CIS to the electronic KE-Jetronic CIS-E which became standard (on US models) in 1984.

The justification: it looks like a fun project, it lets me paint a whole bunch more parts, there may be a slight increase in fuel economy and/or power, and I have a donor vehicle so most of the parts are free.

(Note: This file also might be useful as an outline for part of the process of a turbo engine transplant)

All the detailed information in this file refers to US specification cars, in particular the donor vehicle is a 1984 Coupe and the recipient a 1982 Coupe.

At the most abstract level, this is basically a plug'n'play job. A donor vehicle ('84-'87) is stripped of the CIS-E harness and all the peripheral components involved and they are installed in the recipient vehicle ('80-'83). The reality is not even much more complicated than that. There are a couple of issues that must be planned in advance though, due to differences in the block and head mostly. The crankcase ventilation hose on the lower left side of the block won;t be used since the early block casting has no place for it. Unles the head is swapped as well, the air shrouded injector system will be scrapped and its hose from the intake boot eliminated. I may very well swap heads at a later date, after getting some "work" done to a later style head. A sensor or two on the recipient will not be used, they can just be left in place or plugs can be used. The vacuum brake boost system will be reduced to one source unless you swap the head, in which case the pump may still be installed.

Note, some of these parts I sourced at Atlantic Imported so the numbers may be weird

Now the fun starts. You should have three "things" in front of you at this point. One would be your working CIS car. The second would be a pile of stuff that constitutes the CIS-E system from the donor, with all appropriate cleaned peripherals and new gaskets of various types. The third will be all the tools you will need, which includes the car you will drive to get the parts you forgot in, and that you will drive if your car doesn't run right away. (Note: when I say "discard" in the following, I mean carefully place in a clean box just in case you have to reinstall - and so you will have a nice neat pile of stuff to help others with CIS problems out)

Pull fuel pump relay while the engine is running to lower fuel system pressure as much as possible.
Disconnect battery ground and fold out of the way.
Remove stress bar (save)
Disconnect throttle cable and cruise control rod, remove cruise servo and tuck all out of way.
Remove vacuum hoses from infold manitake (discard all except brake booster main hose)
Remove intake boot (discard)
Remove fuel tank vent valve and lines (save)
Remove battery (save)
Disconnect oxygen sensor
Disconnect the rest of the CIS harnes wiring: coolant sensor in pipe along block, one wire at each coil terminal, hall effect sender connection at distributor, WOT switch, frequency valve, grounds on battery tray.
Remove throttle body for ease of motion (discard)
Remove distributor cap (fold out of way with ignition wires)
Gently pull the ECU harness wiring out of the way, hang over fender.
Open main fuel lines at rear of fender - watch out for residual fuel pressure spray. Undo them and cover exposed ends on the car with baggies and elastic to keep clean.
Remove control pressure regulator from port side of block.
Remove injectors from the head.
Remove cold start valve from IM or just pull its wiring if your new IM has the CSV installed already.
Undo airbox clips and remove the fuel distributor/airbox assembly, with the CPR still attached. (discard except possibly the injectors)
Remove lower half of airbox for working room (save)
Remove intake manifold. Pray that none of the 8 bolt heads are stripped. (discard)

If any were stripped, drill the head(s) out and you will have to remove the exhaust manifold or cut the bolt between the head and the intake manifold to remove the IM. Either way sucks... I would not want to cut one of those bolts on a head I wanted to use, a few stray recipro saw strokes could mar the manifold mounting surface badly. I was swapping in a powder coated exhaust manifold and downpipe (4kq style) anyway, so I had to pull the exhaust anyway. Yes, one bolt was stripped. Took me a good hour with a right angle drill to get the head off the bolt, too.

At this point I pulled the cam cover and replaced the gasket since it was easy and mine was leaking a bit of oil. Turns out that if one uses acorn nuts on these studs, the nuts must have washers in order for them to hold the cover down properly. At this point you can also swap in a cam cover retianing rail with two built on nuts for the injector bracing piece like I found on my donor car.
Pull the CIS harness through the firewall into the passenger compartment. It can be completely removed by pulling the female spades from the relay sockets and cutting the one brown wire.
Enlarge the hole where the harness was, from about 1" to about 1 5/8". I used a nibbler and cleaned it up with a round file.
Now is a good time to remove the injector seats, clean the holes in the head, and install new ones with new gaskets under them.
You should also ensure that the manifold mating surfaces are clean and flat, likewise the throttle body to intake manifold surfaces, CSV mounting area, etc.

Clean up the general fender area you have exposed by removing everything on the starboard side of the engine. If you have surface rust here, or especially on the battery tray, now is the time to clean it up and paint.

Remove the old distributor and replace immediately. You should make a note of the rotor/body alignment and maintain it to keep your timing somewhere close to what it was. This is only necessary because the Hall effect connection is different (or was in my example). Use a new distributor to head gasket.
Install the exhaust manifold and any other exhaust components removed previously. This is when I installed my new warm air intake plate also, since it mounts using one of the EM studs.
Route the ingine compartment portion of the CIS-E harness through the hole in the firewall and seat the grommet in the (enlarged) hole. The big fat bundle should turn straight up and slightly to the starboard when seated.
Lay its wires in their appropriate general directions and locations.
Connect the coil wires, grounds, and distributor Hall sender connector.
Remove the vacuum switch to the rear port side of the block and replace with a plug and new gasket.
Remove likewise the old CIS temperature switch in the coolant pipe and plug.
Remove the upper radiator hose to head flange and replace it with the CIS-E version. This will have the CIS-E thermo sender mounted in its lower side and a plug in the top. The top hole is where the coolant temperture gauge sender is in later cars, the older car can retain its block mounted sender. You will spilla little coolant but not much if you're careful.
Connect the thermo sender wiring to the sender.
Install the CIS-E intake manifold to the head. You will see why one or two of the bolts are prone to stripping - it is very difficult to get a tool accurately into the bolt heads to tighten them properly. Be careful and it will be alright. By no means should you reuse any bolts that are losing their head integrity! If this ever has to come of again you want it to be easy!
Install the lower airbox. One part I forgot to buy new was the two rubber grommets that hold the outboard pegs of this piece. Now is when you should do any intake air routing work - I installed an aluminum flex hose to the warm air plate and another one to the "trailing arm brake cooling duct" I bought at a local speed shop which mounts sweetly behind the lower grille area. The right angle inlet piece from an 87.5 coupe has a single 2.5" inlet, the same size as the duct I bought. Typical 84-85 cars have a double inlet system, with a Y-pipe going to an inlet behind the fender and to a duct behind the headlights.
Put in a new air filter or the best one you have lying around.
If the throttle body was separated, install it now with a new gasket.
If the CSV was separated, install it now with a new gasket.
Attach the WOT/idle switch wiring and the CSV connector (which is part of the regular car harness)
Install the IM - EM braces (if possible).
Install the two four way hoses and the ISV to the intake manifold and the cam cover.
Plug in the ISV connector.
Install the battery, keeping the wires that go behind it (fat red wires, oil temp sender wire, coil wiring) neatly laid.
You may reconnect the battery + terminal but kep the ground disconnected and out of harm's way for now.
Install new injector seals on the injectors (moisten with a little gasoline first)
Install the fuel distributor/airbox top assembly with the injector lines. This will take a little wriggling around. Lay the fuel lines as neatly and close to where they go as possible, and install the injectors and CSV line.
Attach the potentiometer (outboard of airbox) and control pressure regulator (inboard of airbox) wiring to the clips on the airbox and plug them in. Attach the ground wires to the intake manifold stud provided for this purpose.
Cobble together the fuel tank vent system and install the intake boot carefully.
Install the cruise servo and attach the throttle and cruise linkages to the throttle body. Adjust their lengths aas necessary.
Plug all the extra connections to the brake servo vacuum line and attach the main on to the intake manifold. Plug the IM connection next to the brake one.
Check around for wiring I forgot to tell you to reconnect, make sure everything is neatly placed and tightened.
Hook up the ECU wiring - the wire goes to the AC system (I don't have this so you're on your own here), the wire goes to the wire form the car, this is a "ignition start" terminal shared by the CSV, and the and wires go to the wire, which is a fuel pump relay switched power lead for the ECU and for the OXS heater.
You are free to make your own decisions as to how these should be finished out. My FPR has a built on fuse so I wasn't worried. You could use the stock ECU relay and two fuses here if you want.
Install the ECU, altitude sensor, and ignition control unit to the harness under the dash.
Double check all your work.
Triple check all your work.
Reconnect the coil wire if it still loose.
Reinstall the fuel pump relay.
Reconnect the battery ground terminal.
Try to start the car... it will take a moment because the fuel lines are dry, the pressure has to build up. Also at first, if it catches, it may be quite rough since any cleaning agents you used in the intake tract and injector holes will ahve to be burned off.
I was lucky. The damn thing ran right away. I have adjusted the timing be ear, and now I just have to ensure that it is tuned up - and my Bentley is useless!
When the car runs, it is time to mount the three underdash components and clean up the mess in the car!

CIS-E is new to me and I don't yet have the appropriate manual (though I do own the Bosch fuel injection book).

Basically the adjustments that are required are:

Adjust mixture at idle til differential pressure regulator current oscillates around 10 mA.

Adjust idle air screw while monitoring idle stabiliser valve duty cycle at test connector, aim for 28%.

These should be done concurrently, with the usual frustrating list of vent hoses disconnected and plugged.

I'm still tinkering with the timing, I really need to do it right, 3 degree increments from 3 to 24 or so, with a test drive at each setting on the same route, to pick the best point.

In the meantime it is running quite well.

Two things I will be looking for at this time - fuel economy and "driveability," or ease of starting (especially warm not hot starts) and idle quality, etc. As the weather changes cold starts and idle will be more observable.

There also are power issues that might be noticeable at times.

So far, my first tank of gas, in spite of the system running open loop for the first couple of days, has yielded about the same mileage as the old system, maybe slightly better - in the 27 mpg range. This is good I think...

The next tank will be biased by being half burnt on the round trip to Mount Washington, which is pretty much all highway miles. Last year I broke 28 mpg on that tankful.

Over 290 miles, including the Mt. W. jaunt, I burnt 10.3 gallons of fuel (28.15 mpg). While I expected this to resemble highway driving it really didn't. There was a lot more traffic than last year, so instead of just putting along at 70 on cruise control, it was all mixed speed, passing, going slow, etc. driving. The last 8-10 miles were spent entirely in third gear at 85 mph or over, which may be what this car was designed to do perfectly, but surely isn't good for the best fuel economy!

More results... following two tanks at 28 mpg, I had one at 27. Not thrilled. Then I noticed a very small gas leak at one of the fitting over the front of the air cleaner cover (the one with the 10 mm hex socket) and tightened it carefully. I just refilled the tank, after doing that about 1/3 of the way through the thankful, and drove 446 miles on 15.4 gallons. That is 29.0 mpg!

At first upon starting the cold engine, the idle would drop to about 700 rpm and then kick up to about 2000, and repeat this cycle a half dozen times over about a minute, kicking up to less and less till it settled down. I richened the static mixture a bit, and now it only does the one jump, and only when dead cold. Considering I probably have some air leakage through my almost certainly shot valve stem seals, this is pretty good for a 17 year old car with a 15 year old fuel system on an engine with about 145,000 miles on it.

The report on starting - this is great. I almost always get a flick of the key start, cold, hot and warm. If not a flick, it is still at most a one second crank time. This was one of the reasons I wanted to do this swap. My car used to take a few seconds to start when warm. The donor vehicle, which had not been run for at least 10 months, fired right up when I attached my battery charger to it.

I guess now I'll wait for the cold weather performance feedback. Will they use MBTE this year and ruin my mileage? The old system used to drop from 27 ish to 22-23 mpg in the winter.

The following files display some photographs of this job:

Parts Display - The harness and all the various parts all laid out.
Fitting Detail - Close ups of a couple of connections.
Removing CIS - Gutting the old system...
Work in Progress - More and more bits are added until -
Final Results - Two photos of it all assembled.

I'm afraid I didn't do a particularly good job of documenting this job - I took lots of pictures, but they don't really seem to "tell the story" the way I'd like. Maybe I should just hang up those photojournalist fantasies...