930 EFI Conversion in process

[Jim2]

This thread started in August of 2006


I started an EFI conversion on my 930 and plan on having it running in a couple weeks. I'll do some updates along the way.

I've been wanting to do this for a couple years but the cost was a holdback considering I would also need manifolds and injectors etc. Then a couple months ago I saw an ad for some fair priced Carerra manifolds and I found myself knee deep! Could not resist, cost aside. Wife is going to ban the credit card.

My car is a 79 930 with a fresh motor back when I bought it in 2001. Has 964 cams, twin plug heads, and the usual bolt on performance bits, Garretson IC, K27-7200 converted to K28, Powerhaus headers, open muffler etc. I don't really care to chase HP numbers so I don't have any dyno info to share (never been on a dyno) but lapping with some other cars displays the expected power for this combination.

My expectation of the EFI conversion is to take advantage of the Carerra intake manifolds which will improve midrange and off boost torque (930 achilles), be able to map A/F ratio and timing, and utilize the second set of spark plugs.

SDS is manufactured locally hence my choice and I have a friend who I lap with running the same setup on a non-turbo SC with a built 3.4 motor. He had lots of good pointers for my installation.

BTW this is my second EFI intall. The first one was an aftermarket analog system manufactured in the mid 80's which was intended for RVs with V8 engines and throttle body mounted injectors. Since it had four injectors I was able to adapt it to a turbocharged Datsun 510. This is near the time that my turbo sickness set in. Lots of year ago and still no recovery!

Back on topic, the system came with two manuals, one for EFI and another for the ignition. After a thorough read (and re-read) it appeared my first aspect of the installation would be to mount components which could be done while keeping the car mostly in service. I'm only at about step number 3 of about 20 or so steps, so to say.

I scoped out most of the installation and figure I'm aware of the potential issues, but the advice from my friend with the SC seemed thorough short of turbo plumbing.

Ordering the system was simple but I did have a bit of confusion determining lengths of various wires for the wire harness. I should have done more homework using string or wire to do a mock-up of the wiring layout and lengths. As I type this I'm just at the point now where I will find out if I screwed up.

Here is the system: engine control unit, coil packs (two for the twin plug system) programmer, wire harness, and several sensors. Also a bag of gold..., or should I say new injectors - worth their weight in gold! These things are so common now you would think the price would have come down.



Next I stripped the back of the car to remove the crank pulley so I could install the electronic pick up, and mount some magnets on the pulley.


The manual says to ensure that TDC 1 is accurate. I put a wire in cylinder 1 and turned the crank to feel for TDC (with my eyes shut) and I was able to repeat it 5-6 times consecutively. I found the mark was off by about 2 degrees which I later found out was slop in the pulley locating dowel.


I have a small mill/drill and a rotary table I used to index the magnets according to the manual, but the manual has a very clear method of doing this for the DIYer without a mill.


The holes are 1/8" by 1/8" deep


Hard to see, but the magnets are epoxyed into the holes here. They fit pretty tight. I found the pulley has just enough meat to accommodate the magnets. My friend with the SC built an aluminum pulley and had it hard anodized. He had a shoulder to accommodate the magnets. I also machined off the A/C pulley groove and static balanced the pulley, but this was not necessary.


Continued...

Jim

[Jim2]

Here is the pickup and a spacer shim I made from aluminum to bring the pick up the appropriate distance to the magnets



I traced the location for the pickup onto the engine case then drilled and tapped some mounting holes for my shim


Here the shim is mounted


Here the pick up is mounted


Reinstall the pulley, loctite, torque etc.








Continued

Jim

[Jim2]

The system uses a A/F ratio control knob for diagnosing rich or lean during tuning. This knob gets turned off via the programmer until you need it again. It sounds like you could bump it and do severe damage to your engine if you leaned the mixture, but it looks like it will be easy to drive and tune with the knob, then pullover to adjust the maps in the computer - one man operation? I'll find out.


While I had the rear engine mount removed to get at the crank pulley I lowered the rear of the engine then removed the air cleaner assembly so I could mount the coil packs. I copied my friends intallation in his SC. I cut the mounting plate from some scrap 1/8" aluminum and bolted it to the rear crossmember seam, and put a couple stand offs through bolted to the rear firewall. I also bent up the end of the plate so I could mount the manifold pressure sender. I did not need to be this elaborate because the sender could have been zip tied on something.






I rplaced the rear engine mount and noticed that it colided with the cranck sensor by about and 1/8" so I trimmed the mount a little.


I also drilled a half inch hole to make it easier to tighten the one mount nut. The alternate was to butch up a wrench.


Per the manual for the ignition it suggested mapping the timing curve for the distributer. I forgot to take pictures, but basically I used a timing light and noted timing at: 500 rpm intervals to measure the mechanical advance with the vacuum/boost hoses removed from the distributer. This isolated the mechanical timing. Then I used a vacuum pump to simulate vacuum advance and noted this at 5" mercury intervals. Finally I did the same thing again using a pressure regulator to simulate boost on the boost retard side of the distributer dashpot.


At this point I used about four long evenings and an entire Saturday, and of course, a case of beer.

I pulled out the manifolds and started cleaning them up. They were really badly coated with EGR residue. Next I will have to make a small adapter to hold a throttle position sensor to the end of the butterfly shaft. It looks like the Bosch one which comes with the manifold but the original is actually a switch, not a potentiometer. Pics to follow. I'll start stripping the engine bay of intake, distributor, CDI, fuel metering unit, plumbing etc this weekend.

Jim

[beepbeep]

Great writeup! SDS is very nice and trustworthy system, albeit somewhat baulky when it comes to mapping (no laptop).

Talking about ignition timing: it get's messed up with years. You could copy your buddy's 3.4 Carrera timing, retard it couple of degrees to be on the safe side and start chasing AFR's.

Do you have access to Wide Band O2 sensor? It's quite hard (almost impossible) to do a good map with just narrow band O2.

Good luck!

[930Jim]

Good post. I'm in the middle of an EFI conversion myself and this is very helpful.

[hobieboy]

Jim,
Great description & good luck! A buddy of mine also did the same, see this SDDS link - http://www.sdsefi.com/features/jan03934.htm

His car had been very reliable and throttle response from the system apparently is very good.

I'm in the EFI process as well though still struggling - I went with Megasquirt and still trying to get the car started (no sparks ). In fact, SDDS is fast becoming my potential plan B

[MikeY930]

looking very good, let us know how she runs when your done

[WERK I]

Great post, great photos, Jim. I look forward to hearing all about this project. Good luck!!

[slow&rusty]

Great write-up and awesome pics too!! I am staying tuned as I am going this route hopefully soon in my own 930.

Yasin

[jpnovak]

Great writeup and clean install so far. Can't wait to see the finished project.

[DW SD]

Great post and project!

Doug

[Jim2]

Hi all, here is an update on my EFI install.

Beepbeep, I currently have a narrow band o2 with a visual dash gauge, but I plan on trying the o2 feedback data logging in the SDS computer. If it is too difficult using the narrow band o2 I have a line on a wideband which I can borrow for tuning, or I might just buy one.

Last point I left off at was mapping the distributer. I then stripped the engine bay. Here is the before shot.


And here is the after...WOW!




Now for a change of topic, I decided to mount the TPS (throttle position sender) Here is the sender pushed onto the throttle shaft of the Carerra throttle body:




Here is the adapter I made up from a small scrap of 1/2" thick aluminum. Again I used my small milling machine but a hacksaw and a file would have sufficed. The spacer needed some clearance for the plug which connects to the sender.








Here it is installed:



At this point I reverted back to working on the car. I decided to pair down the wire harness and trace all the wires. The 930 is pretty simple. I managed to identify everything without a schematic. Most of the CIS system is interconnected and uses simple 12v in and grounds. I very thoughly labeled all wires before disconnecting and trimming. Sure looks like a mess!:



edit: Stripping the engine bay of the entire CIS, intake, plumbing etc took about 5 hours including removing the long intake port studs. The tps adaptor took about 2 hours. I'd say about a half a day to pair down the harness and identify the wires. Another couple hours for cleaning, puting the car on stands, and scratching my head in shallow thought - wondering, WHAT HAVE I DONE!


Continued

Jim

[Jim2]

Continuing on the wiring topic, I decided to get it out of the way because I knew I would have to crawl under the car and route wires. This was not the most fun thing to do.

I previously decided to mount the computer behind the drivers seat then run the wires through the wall of the tunnel near the shifter access panel, then through the spare bulkhead hole to the engine bay. I'm thinking this installation has to be done as good as the factory becasue it is permanent, never to be reverted back to CIS. Upon closer inspection I found there were far too many obstructions in the tunnel, and I did not like the proximity of the transaxle and mount to the rear opening of the spare bulkhead port. Seemed as though if any part of the wiring were to potentially touch the transaxle, vibration and movement would abraid the wires.




Plan B: I took a hole saw and created a new port next to the location where I decided to put the computer:



Looking into the hole, the torsion bar tube below, and bottom of the rear seat pan is above. Hole is 1 3/8":




I built a mounting panel for the computer. I screwed it to the cargo or child seat tie down point behind the drivers seat:




Beer break - midnight




I bundled the wires into four clusters and threaded them through the undercarriage from the hole I created. I followed the same layout as the factory wire harness on the passenger side. Difficult to take photos... The hoses are boost control, mech boost gauge, and a couple spares for diagnostics. The hoses are routed back through the original spare hole in the bulkhead leading into the tunnel.




Here is a grommet I split and put around the wires. I put sealer around it, then when the system is running, I'll fill the space between the wires with silicone to stop any water from entering. The computer is very close to the other side of the grommet and water could migrate to the computer if it were not sealed.



I mounted the computer and connected the various parts of the harness. If I could make a suggestion, I would seriously consider looking at perforating the back seat to route wires to the engine bay. Though I tried to follow the factory path under the car, I estimate that I spent a clear day, wrapping and pulling the four small wire bundles and my five hose. The back seat seams so practical, as long as you can hide the wires under the seats and carpet. I estimate I spent a casual Saturday and Sunday to mount the computer, do the layout, wrap and complete the wiring install.




Shield over the connectors:





Continued

Jim

[Jim2]

Yet another post tonight...

With the majority of the wiring out of the way I decided to get on the intake adaptors. My friend running the SC with SDS told me about these adaptors but he was unable to articulate what the fitment issue was since shipped his intake and heads to someone who made the adaptors for him. His are made from phenolic.

Upon comparing the Carerra manifolds to the 930 heads I found the electronic injectors are set about 3/8" further out from the port, as a result you can't just put the Carerra manifolds onto the 930 heads because the injector would be partially covered over, and there would be insufficient mating surface to retain the gasket around the injector. (Not sure, but I think heat soak back on the 930 might boil fuel in the efi injectors without any isolators)

Here is a tracing of the 930 and Carerra gaskets. The crosshatch area is the 930 gasket, and the wedge pointing off to the pencil is the Carerra gasket allowance for the efi injector:




My solution: I located a chunk of bakalite which my brother acquired for an electonics project. (5/8" thick). I traced the shape of the Carerra manifold onto the bakalite and cut them out with a bandsaw:




Here I marked the center of the port hole then used a hole saw to cut out the port hole. A dull 1.5" hole saw seemed to be the perfect size:




I slipped both a 930 isolator and one of the new ones over a piece of 1.5" tubing to keep them aligned, then pilot drilled the stud holes:




The 930 isolators (and the Carerra manifolds) have a ledge which seals against the engine fan shroud. I used a 930 gasket as a template to trace around, then free handed with a router to cut the ledge. It was a little difficlut to set up, but the result was sufficient, virtually identical to the 930 part. I also added the notch for the fuel injector to one isolator and trimmed the edges with a belt sander:








Here I tried to capture the difference between the two injector locations. The 930 isolator in the background has the injector located about half of an injector diameter into the isolator wall. The new isolator for the Carerra manifold has the injector located about one full injector diameter further out from the port (hope this makes sense):




I estimate that I will have a full day into making the isolators once the injector notch is filed into all of them.

Car awaits me! or I can't wait.

[SteveM911]

Excellent write up and pictures Jim.
I like the way you just get on with a solution to the problems you encounter.

Good luck with your project.

[Jim2]

Here is an update to my SDS fuel injection installation.


This last week I completed the wire harness installation inside the engine bay. It was simple to hook up but lots of hours to do a tidy installation with all connections soldered and heatshrinked. I also had to go back and add some disconnects so the engine could be removed. I made a mount for the factory voltage regulator on the right side of the coil packs, then mounted two relays on the left side to power to the coil packs and the injectors. It's tough to see but the wire harness is entirely behind the coilpack panel. I left one power wire and a ground near the old rear panel location for testing or hooking up a timing light.



I didn't have any of the throttle linkage parts from the Carerra besides the 6" long rod connected to the throttle body. The Carerra and 930 linkages are similar but I needed to move the ball stud on the engine so it was facing the drivers side, then rework the arm so it would be near the 12:30 position and add some material to build up the WOT stop. Previously the arm was at about the 11:00 position.



On the throttle body I moved the arm to about the 4:00 position from the 5:00 position and removed the extra linkage parts from the stock Carerra application.



I have a MSD knock sensor with an audible and visual display inside the car (audible part is a joke) I drilled the intake manifold and tapped the hole to accomodate the knock sender.



I think I'm up to about 2 or 3 cases of beer, and about a half a dozen starbucks along with an equivalent amount of aspirin to relieve the back pain from leaning into the engine bay.

I wrote up a list of items to be completed. Looks like another week before start up, and it will still be missing the intercooler.

Jim

[89turbocabmike]

Nice progress Jim. The spacers really came out nice, nice routering touch. Hope replacing the head studs goes smoothly

[DW SD]

Great update! May I ask why you are mounting the knock sensor to the intake rather than to the case, or block somewhere? Any chance the noise would be filtered out by your isolators?

Doug

[rfuerst911sc]

Are you concerned about heat buildup of the ECU being under the carpet? I was thinking of mounting my MS ECU in the same spot that you did but decided to mount it under the drivers seat for better heat dissipation. Your install looks very nice. Good luck

[Jim2]

Turbocabmike, I had difficulty getting studs the length I wanted so I bought some allthread rod and cut it up. One of the inlet port stud holes is blind and the other is open. For the open ones I'll just use a spot of blue locktite.

DWSD, I had the knock sender mounted to my 930 intake and it seemed to work fine. The pickup/gain is adjustable. The pick up seems to be very sensitive.

rfuerst911sc, I never even thought about heat build up. I'll call the SDS guys next week to see if my mount location is an issue. It didn't say anything in the manual though. Thanks for the observation.

Jim