Porsche CIS Fuel Injection Re-Build

[@tycotoys]

I used this video along with a diagnostic call to Kurt to fix my 74 Targa 2.7, I knew nothing about this car but was able to get car up and running correctly because of this video and Kurt. Ended up replacing Fuel pump, Accumulator, fuel tank strainer, had CIS Flowtech rebuild and ship me a correctly functioning WUR. Ignition system, plugs, wires, points, cap and rotor all replaced with correct non resistor type. Started car, adjusted sensor plate way back because someone over adjusted to compensate for bad WUR and fuel pump. Also changed out fuel tank strainer, actually didn’t look too bad, tank was clean. Runs perfect now. Thanks Kurt ! Bill from PA

[@klassikats]

Your welcome Bill, Thanks for the glowing review. glad everything is working the way it should now. Kurt

[@charleseckberg1947]

Knocked it out of the park. The most comprehensive Porsche repair content I have seen. This needs to be shared with the members of the different Porsche groups, clubs, and forums.

[@klassikats]

Thanks Charles Kurt

[@marien9695]

Probably the most comprehensive CIS video on KZbin, it is extremely helpful! I have a 1991 Volvo 940 with factory CIS and after 300,000 miles, the O-rings and gaskets are starting to dry out, leading to air leaks. Also, the injectors are factory, so probably time for a change too :-) You clarified everything so well!

[@klassikats]

Thanks Marien, glad the video helped Kurt

[@icbtech01]

It's such a pleasure to watch and learn from someone who is articulate and clearly knows what he's doing. There are far too many clowns putting videos out on YT that shouldn't be allowed to own tools, much less work on anything mechanical. Thank you for sharing solid knowledge, Kurt.

[@klassikats]

Thank You Kurt

[@frankmoron5787]

ws gettin ready to crap myself till i saw this vid, i feel a lot better now that u broke it down for us. thankyou very much! i ve been wondering about the toilet seat or not to toilet seat. hard to drill a hole into a nice new box and goop it up w glue since some say its the fix and some say no. since u explained the foam gasket and screws w springs it s clear the factory has addressed the issue. i ll try no pop off first. thx from terry in mendo

[@klassikats]

Glad to help. Kurt

[@thomas2857]

Totally agree - this is one of the best Bosch CIS / K-Jetronic videos if not the best ever because you name all the key comoponents and their adjustment, especially the sensor plate. Congratulation! Please keep up this competent work! BUT: I have to disagree on one single point - the basic setting of the CO screw / begin of injection at the fuel distributor. Bosch recommends the following procedure: All injectors connected and placed in to the intake tubes, sensor plate adjusted like shown in the video and with no lift as the engine sits, switch fuel pump on, and begin turning the CO screw cw until the injectors start to inject by hearing their squeaking noise and then turn the CO screw half turn (ccw) back. Done! Fine tuning of the mixture afterwards with a gas analyzer with warm and idling engine as the workshop manual tells. Done.

[@klassikats]

Thomas, yes, I have used the method you mentioned. Both achieve the same starting point for a first start. The only thing i dont like about that method and why i dont use it is that you have the possibility of loading the cylinders with fuel. For an experienced mechanic that gets all the settings really close to begin with this is not such a big deal. However for someone that does not really know how every thing works it can result in a fouled plug on start up. Thanks for watching and thanks for the input Kurt

[@thomas2857]

​@@klassikats OK, got it. Flooding the cylinders with fuel is a point. But on the other side and as you wrote - an experienced mechanic wrenching on these cars should be aware on this. I guess this is the more precise way to get an initial setup. Another advantage on this I see is that all injectors are connected to the fuel distributor because the pressure readings may vary from cylinder to cylinder. With this method you're closer to the point where all injectors start spraying...

[@johnfreeman1189]

Never seen this done before. Thanks for another great video

[@klassikats]

Thanks for watching! Kurt

[@drblast]

What a great informative, useful and helpful video! I'm applying the aspects of this video to the '79 928 I'm working on currently and I've done many of the tips you mentioned just from general mechanical 'muscle memory' per se, but some stuff I was like wow, glad he mentioned that. Subscribed.

[@klassikats]

Glad it was helpful! and thanks for the subscribe. Kurt

[@notnilc20]

What a God-send this video is. All I can say is THANK YOU THANK YOU THANK YOU!

[@klassikats]

You're very welcome! Kurt

[@pauldaly3589]

Fantastic, I have a 2.7 and need to learn to be able to test and tune from zero base knowledge, this is an amazing video. Thank you.

[@klassikats]

Glad it was helpful! Kurt

[@aqa321]

Such fantastic videos. My 1978 928 project has been guzzling fuel and your videos have been incredibly useful pinning down the issues (so far looking like the WUR). Thanks so much

[@klassikats]

Glad to help Kurt

[@michaelkost238]

Another fine piece of Information about the 911. Wish i hadfound this a couple of months earlier. Did this renovation on my shortly bought 3.0sc us. Had exactly tha aluminium pipe rubbed through.

[@klassikats]

Michael, Yes that pipe is always damaged to some extent. Thanks for watching Kurt

[@911engineguy]

Great info. Well put together. Would be good to see your tumbling process on the intake manifolds :)

[@klassikats]

Hey Michael, You can see our cleaning process including the tumbler in our 911 cylinder head section. We pretty much tumble all the aluminum and mag parts we handle. Thanks for watching Kurt

[@davidwilburn6314]

Fun to watch, even though I removed my '80 SC CIS years ago to make way for much newer injected throttle bodies, dual plugs, cam change, SSI yada yada. Now I've got a cardboard box full of relic parts sitting next to the upright compressor.

[@klassikats]

David, Thanks for watching and dont get rid of those relics. Their getting harder to replace and worth more and more money

[@davidwilburn6314]

@@klassikats Yep!

[@cheesewhiz32]

This was very well done and very helpful in demystifying CIS components for me. Thank you!

[@klassikats]

your welcome, glad I could help Kurt

[@marionfisk7926]

Great video Kurt. the injection system to me it’s been a mystery now, I have an understanding of how each of the parts in the injection system work and hopefully I can do the cleaning and refreshing of some of that system myself when I take the engine out of the car. Thank you

[@klassikats]

Your welcome and glad it helped Thanks for watching

[@michaelkost238]

Unfortunately this pipe is special for the 82 US Version, this one has an additional connection and of course is no longer available. I had some luck finding a pristine used part at 50 euros. Still working through your videos. Very impressive. Thanks for sharing.

[@klassikats]

Yes, and that pipe has been NLA for a long time now, making them much harder to find on the used market. Glad you were able to find one to keep your car running. Kurt

[@claudevoyer7124]

This was great and very explanatory.

[@klassikats]

Great! Glad you liked it. Check out the diagnostic CIS too. kzbin.info/www/bejne/qZ2mq4mop7iHaLM Thanks for watching.

[@chuckglass8849]

Excellent info, thanks for sharing.

[@klassikats]

Our pleasure! Kurt

[@OTTOFOX]

Great video! Had some issue setting my fuel system up but your video was easy to follow, Thanks a lot! :)

[@klassikats]

Glad it helped! Thanks for watching

[@roeljanssen1982]

Again a very impressive video!! I’m working on the same system at this moment, this gives me so much guidance. Big thanks for that! I have one question about the fuel lines… if the rubber isolation is crumbling. Would you replace them? And can they be re-tubed? Of have you put in a whole new set?

[@klassikats]

Hi Roel, No the outside tubing is fused on and can not be replaced. Get a new set if you are worried about it. If it really is just the outside abrasion protection and not the inner polyamide line you could run as is. Thanks for watching.

[@356classiccars4]

Superb guide. Thanks

[@klassikats]

Glad you liked it Kurt

[@kazstrankowski8721]

Another great, informative video!

[@klassikats]

Glad you liked it! Thanks for watching

[@kevinsamuels5868]

What a super video Thank you for sharing your knowledge. 👍

[@klassikats]

Glad it was helpful! Kurt

[@pauldaly3589]

Your videos are wonderful, thank you ever so much for posting. I’m working on my 2.7 CIS - I see you adjust the position of the sensor plate using the adjustment contact for the safety switch. Others have recommended first setting the level of the sensor plate using the 3mm mixture screw and then adjust the position of the safety switch contact. I’m a bit lost as to the correct order, is the order important ?

[@klassikats]

Paul, Firstly the mixture screw has no effect on sensor plate height so no you cannot adjust the plate height using the screw. Also no I am not using the sensor plate fuel cut off senor to adjust the height. On the 2.7 and 3.0L engines there are two types of adjusters. on the early cars it is adjusted by bending the a small metal clip on later sensor plates there is a small adjusting screw and lock nut that adjust the sensor plate height. Thanks Kurt

[@pauldaly3589]

@@klassikats Kurt, Thank you so much for your help - now I know what to do. Can’t thank you enough. Paul

[@James_LDN]

Incredibly useful video, thank you so much for taking the time to film it all. I'm looking at the new air box sitting in front of me on the table; the old one is split exactly where you mentioned due to backfiring. My question is whether it's possible to change the air box without dropping the engine at all. It seems that there are some slightly fiddly connections to sort. Many thanks.

[@klassikats]

James, Yes I change air boxes all the time without removing the engine. All you need to do is just lower the back of the engine so that the air box can slide out over the top of the alternator. Yes there are a few bolts that are tough to get to but all in all its pretty easy. Thanks for watching and good luck Kurt

[@James_LDN]

@@klassikats Many thanks Kurt, I shall give it a go. Might make a video of it so you can share a 'how absolutely not to do it' episode : )

[@BCloss90]

Amazing video, crystal clear explanations! By the way, I just put together a CIS system on a 79 911SC. We did cosmetic rebuild on the system. The engine is all assembled in the car. It starts, but immediately dies. Appears no to have idle. basically. Any tips on where to look first? If I move by hand the air sensor plate, the car will rev up, but wont keep idle. Thanks a lot!

[@klassikats]

Bruno, Sounds like the engine is starting on the cold start injector then it runs out of fuel. Most likely place to start looking is cold WUR pressures. Sounds like that the cold fuel pressure is to high. Thanks for watching Kurt

[@jasonwright9555]

I keep getting distracted by these brilliant video tutorials! 🙂 I really need to get on with some work. Regarding the smoke testing. Is the brake booster port also a good location to connect the smoke to whilst the engine is back in the car and completely plumbed in, or would you suggest another more suitable point? Thanks again Kurt, top work!

[@klassikats]

Yes that will work. Kurt

[@russelllamborn892]

Like to watch your videos, , special Porsche CIS fuel injection re-build. My Porsche can't start, I found out the roller bearing of mixture control Unit is stuck, not move at all. I tried to put some oil on it for a few days, still not moving, could you please advise how to fix it and get to move freely again ? Thanks.

[@klassikats]

The way I usually fix the frozen roller is to use a light penetrating oil and then keep working it back and forth until it frees up. However I have never seen the roller cause a no start condition. That will usually be something else like fuel pressures or no spark. Kurt

[@adi4208]

Well done, thank you so much! I am rebuilding a 911 SC 1978 with the CIS System, and i have to change the air box because of lekkage. Why didnt you use the pop-off-valve on the new airbox? Thanks for sharing your knowledge!

[@klassikats]

I dont use them because they dont work and usually result in vacuum leaks. Drilling a 1 1/2" hole into a $500 part makes no sense to me. Kurt

[@adi4208]

That's a point, thank you 👍

[@slavoexploresamerica4495]

@klassic - would you say that theoretically I could just remove and seal the pop off on my existing unit?

[@Groovecorrecto]

So great video. Very comprehensive. Do you think installing an SSI exhaust on a '82 SC, but keeping standard CIS could have any benefit? Thanks a lot!

[@klassikats]

It will make slight difference. although I doubt that 99% of drivers would even notice the difference. Kurt

[@02powertube]

28:30 What electrical connection is that on the sensor plate housing. Thanks for a GREAT walk thru

[@klassikats]

That is for the fuel pump shut off. it stops the fuel pump from running when the sensor plate is sitting on its stop. Kurt

[@02powertube]

@@klassikats Thanks fornthe swift answer Kurt👍🏻. When adjusting the base setting on the plate, coyld that be done so that the sensor does not work?. If adjusted too high during the base setup?

[@02powertube]

@@klassikats And .. I believed that the fuelpump would run when the plate is at the "stop". If not, how do the system build up the initial pressure?. Thanks in advance

[@tonyreyes9969]

I would like to add additional information about the electrical connection on the sensor plate housing. As its already been said, it stops the electric fuel pump from running when the sensor plate is sitting on its stop position, it is part of the system called SAFETY CIRCUIT, and this is how it works. During starting the electric fuel pump runs as long as the ignition key is operated. The fuel pump continues to run when the engine has started. A safety circuit is incorporated to stop the fuel pump running and fuel being delivered if the ignition is switched on but the engine has stopped turning, for example in the case of accident. I hope this information helps. I love watching your very informative video's. All the best. Cheers!!!

[@02powertube]

@@tonyreyes9969 Thanks 👍🏻👍🏻

[@chrismac2264]

Thanks for the video Kurt, I'm using it do disassemble and clean my 76 911s CIS system. I can't get the flat head screws loose on the fuel distributor. I've tried penetrating oil but they just won't budge. I'm hesitant to apply any shock to them (striking screw driver with hammer) as I'm afraid I would damage something. Any tips on getting these 3 screws to break loose?

[@klassikats]

Just use an impact driver, you will not break anything. Kurt

[@chrismac2264]

Thanks

[@AOMC]

Great video! Can you remove and reinstall the assembled intake with the engine still in the car or do you have to do a partial drop or full engine removal?

[@klassikats]

The intake system can be removed with the engine still in the car. You do however, have to lower the back end of the engine to clear the alternator fan shroud. Kurt

[@katherinecampbell2984]

Hi there, all your videos are exceptionally helpful - thanks! I have a 1991 964 turbo with the Bosch 0 438 120 205 mixture unit (downdraft). I had to remove the fuel distributor from it to clean the stuck plunger. After reinstalling all fuel pressures and fuel volume tests are correct but it will not idle unless I hold the air sensor plate slightly down - I've stuck a tiny allen key between the sensor plate to keep it down. It will then idle ok and once reaching operating temp my wideband sensor reads AFR at 14.7 so fuel mixture is ok. Therefore I assume the idling issue is due to the air sensor plate height. How do you adjust the air sensor plate on this unit as it differs markedly from the one in your video? Any advice appreciated. Cheers.

[@klassikats]

Most likely just a CO adjustment will solve your issue. You are wasting your time with a wide band O2 Sensor and you just need to put a gas analyzer in the tail pipe and adjust the fuel mixtures. When you change the sensor plate position by artificially changing its position you are changing the CO% Kurt

[@katherinecampbell2984]

@@klassikats Many thanks! I've only just been able to get back to the car but I adjusted the CO as per your advice and it solved the issue. It is now driveable so I will have CO measured at a workshop and will adjust fuel mixture to achieve specified CO value (1.0% +/- 0.2% for 964 turbo). But will this only achieve the correct CO at idle - not throughout the rev range? If enrichment is handled by the warm up regulator (mine's been rebuilt and is in spec) and should the car be running rich, do I need to adjust the sensor plate height? In other words if CO is correct at idle, and if fuel distributor and warm up regulator are in spec what else can be adjusted if still running rich (on a 964 turbo with oxygen sensor)? Thanks again.

[@klassikats]

@@katherinecampbell2984 Katherine, The sensor plate height is critical to the correct operation of the system. The sensor plate height in conjunction with the fuel mixture settings being correct set the entire fuel curve. As long as your warm-up regulator and fuel pressure/volumes are correct, then you will not have any issues. The O2 sensor will also fine-tune the fuel curve. However, if the mixture is set to rich or to lean, then it will not be able to effect much of a change. This is why it is so important to set the correct fuel mixtures using a 4 or 5 gas analyzer.

[@diogeneslamp8241]

Question- the roller bearing under the fuel head- should I grease it or oil it? If so what lubricant do you like for that?

[@klassikats]

I use a light machine oil on that roller. You want to make sure to work it in to the needle rollers and not just on the outside of the roller

[@brooklynbrowser5881]

Fantastic videos, really good - thanks. What do you use to clean the oil residue out of the throttle body and around/underneath air sensor plate?

[@klassikats]

Thanks I use Metal Parts Cleaner, (MPS), it is a highly evaporative cleaner that works well. You have to be careful though as it is highly flammable. So make sure you only use it on a cold engine. Thanks for watching

[@nielsvanderzeyst7036]

30:16 great video and it will be very useful for when I tackle this on my 78 this spring. Just curious; you said overhaul of the fuel distributor is a specialist job. I have seen people overhaul them with specialist kits succesfully. What makes this a specialist shop (and thus a 500+ euro) job?

[@klassikats]

putting a kit through the Fuel distributor is only half the job and the easiest part of the job. Setting the fuel calibration and delivery rates is using either springs and shims on the earlier models or the later adjustable models is where you need specialized equipment and some skill. Kurt

[@nielsvanderzeyst7036]

got it, thanks Kurt!@@klassikats

[@jansharawan1358]

Good wark bro 👍

[@klassikats]

Thanks ✌️

[@khamul02]

Cold start valve testing question. I tested mine and it click and spray fuel but after having on for maybe it minute the valve got hot. Not to hot to handle but uncomfortable to hold. Should I replace it or is this common?

[@klassikats]

Tom, That valve is not designed to be on for an extended time. In the car it will only open when the car is cranking and the engine cold. So usually only a matter of seconds. I would expect it to warm up somewhat if it was powered up and left on for a minute or more. Thanks Kurt

[@fakeaccount4092]

Skills thanks man!!!!

[@klassikats]

Happy to help! Kurt

[@zonoscopePictures]

At 19:50, do you use OEM parts for the Intake Runner sleeves or boots, or do you cut some hose to length? (The reason I ask is they look different than the ones I ordered, which turned out to be the wrong size - my runners are -4R and these must have been -2R)

[@klassikats]

I use the OEM intake sleeves. There are several different sizes of intake sleeves depending on your engine and the intake port size and model. 1973.5 Models 911.110.885.01 (smallest) 1974 - 77 Models 911.110.885.02 (39 mm) 1978 - 79 Models 928.110.158.01 (large port) 1980 -83 Models 930.110.885.00 (Small port ) Thanks for watching Kurt

[@dasboototto]

seriously thinking of converting to EFI from bitzracing after watching this

[@klassikats]

Be prepared for even more work. Getting an EFI conversion working correctly is really tough and most never really work they way they should. Kurt

[@dasboototto]

@@klassikats Maybe its six of one and half dozen of the other. My car has this exact engine (76 911S). Its 46 years old. My local Porsche wrench retired so I would have to learn the CIS system on my own. Prices for CIS parts can be pricey. Knowlege wise, I would be starting at zero with either system.

[@rajikhalaf]

kzbin.info/www/bejne/gV6yp52ioNeahNE Great video! Great channel! I've worked on two CIS 911 engines (78 and an 83) and neither had this drain tube or hose. Did they discontinue this on the later CIS cars?

[@klassikats]

Yes the drain assembly was discontinued with the 1978 models and on. Kurt