510 L20B EFI conversion - the project is finished!

[Sealik]

jeff - I've seen pretty good results copying pages by shooting them with a digicam, but you need one with somewhat of a closeup range. Even without pics of the '80 manual, you can look up specs for the various bits n pieces. I'm really curious what your book says about the head temp sensor, or maybe it was called a water temp sensor in '80. Can you look at my post #335 on page 17 of this thread, and see if the '80 spec is the same? Maybe it is the same, even though the sensor is located in a different place. You might also be sure the pin number on the harness connector is the same as what I found in the '81 book. I'm really close to buying an '80 manual myself, just so I can see the differences between the two years. But that would just put me closer to following Matt down the FI path, and I'm not wanting to do that yet. Not until he wins this fight anyway.

 

Len

 

 

Yep.....the tests are the same for the head and water temp sensor.

Haynes has a manual for 200sx. Covers the years 80-83, Z20 and Z22 engine

[bilzbobaggins]

it is the same for the tests.....

 

jefff

[LenRobertson]

Thanks guys for checking this. I'm really starting to wonder if there are any real differences between the '80 non-O2 sensor FI system, and the '81 with O2 sensor. Matt has posted that his guru Joe seems to be running a couple of cars using O2 sensor ECUs, but without the O2 sensor. Could it be the O2 sensor, at least in these early, somewhat primitive FI systems, doesn't do very much at all? Maybe it just slightly tweaks the injector pulse duration for slightly better emissions control? If it wasn't so much work, I'd love to put my '81 Z20e engine in one of my cars, just so I could unplug the O2 sensor and see what happens.

 

Len

[HRH]

IT RUNS.

 

So today is my lucky day apparently. Been fighting with the mortgage people on the home loan modification and my appeal was finally granted, so I'm not going to loose my house it seems. I've tried to keep that out of ratsun threads, and it's one of the reasons I haven't been working on the 510 near as much, because I've been stressed about it.

 

Then, Len calls me up and I got to meet him for a FSM for the 81 200sx, which was greatly appreciated.

 

After that, I went out to pull and save with my Datsun guru Joe, and Len met us there later on. Not only did I find an NX2000 (sad) that Joe needed a spare ECU for off of for the chump car, but there was a smashed in the front '80 200sx that had just been put out in the yard. So I got the entire wiring harness and ECU out of that!

 

When I got back to Joe's shop, we tested the ECU, which was fine. And then I asked Joe about that large yellow wire on the connection closest to the ECU. It has a tee connector with two wires, one goes to the tach for signal, the other goes to the starter.

 

I originally looked at Joe's setup in his truck and saw the wire going to the start solenoid, but I didn't want to run it to that for the start up test, so I ran it to the fusebox instead. So it was 12v constant all the time. Now here's the funny part. I didn't even open the FSM I borrowed from Len, but after I looked at Joe's truck, we realized that that yellow wire goes to the COLD side of the solenoid. It only gets 12v when cranking.

 

I thought about it on the way home and figured out what had happened before I even got home. The yellow wire is a fuel dump. It throws in lots of extra fuel for startup when the motor is cold, then stops after you disengage the starter. So having it constant on explains why it ran pig rich and I could only get it to idle with a massive air leak to balance out the extra fuel. The reason it was fixed the other night was from running it so much with the air leak that it finally heat soaked enough when I shut it off, to reach a bypass temperature. The ECU obviously has a preset temperature point where it disables the extra fuel feature in warmer weather, as it's not needed. So at 160ish degrees, it knew extra fuel wasn't needed on startup. That's why it was seemingly fixed when I poked the positive terminal. It was just warm enough.

 

I'm going to go back now and fix the wiring diagram info I posted earlier in this thread, so as not to deter any other people. Oh, and the engine wiring diagram in the Chilton's manual doesn't show that wire going to the starter. It shows it going to a fuel pump relay and that's all the farther I traced it since it was key on also.

 

That was the whole problem. Definitely a wiring issue. Going about wiring up peripherals now and getting her all back together for winter. YAY! :)

 

THANK YOU EVERYONE FOR ALL THE SUPPORT DURING MY TIME OF STUPIDITY!

 

Here is the updated wiring schematic:

 

On the connector next to the airflow meter pigtail:

 

Black w/ White wire 12 gauge - 12v

Red 14 gauge - 12v

Green 14 gauge - 12v

 

Connector inside cab 6 inches from ECU harness attachment:

 

Little yellow (or blue) wire - Negative side of coil.

Big yellow wire - 12v wired to COLD side of starter solenoid. Power only when cranking starter.

 

Ground ring near injector pigtails goes to grounds. May need a separate ground strap from engine to frame.

[HRH]

And Len Robertson especially, thanks for all the regurgitated FSM info, I'm sorry I didn't actually get to use the FSM! :D

 

[jovial_cynic]

NICE! Glad you got it fixed!

[INDY510]

.

From page 4 of this thread:

 

You probably know this,,,, , but my KA24DE is spliced into the stock datsun wiring.......... because the ECU needs to know when you are cranking the starter

 

 

......... the 200sx must have a starter signal wire

 

:lol:

[Farmer Joe]

OMG!!

 

i wanna see vidz!!

[LenRobertson]

I KNEW once I got the service manual to you, it would solve your problems. But yeah, I did think you would have to open it up and read a little. No matter, it is obviously a Magic Book! I just wish I had gotten it to you a couple of weeks ago when I was in Spokane to the eye doctor. You would have been running that much earlier.

 

So now all the rest of us can stampede into FI conversions. After I left Pull n Save today, I realized I should have talked to Joe about FI intake manifolds for L series. Maybe in all his Datsun collection, he has a JDM FI manifold. I know this isn't supposed to be a good performance manifold due to the small diameter runners, but I'm just wanting a mild street engine. Or maybe he has a preference for a fabricated manifold.

 

I didn't really think you would post the pic you took of me. If it isn't obvious to everyone, I was squinting into the sun. At least I guess I was. Hey, maybe I always look like that! How would I know?

 

Great to hear you have it whipped. And the house thing solved. Buy a Lotto ticket on the way home?

 

Len

[Unclejesse88]

I guess the yellow wire could also be spliced into the turn-on wire to the starter, but it might be easier just crimping a ring terminal on it and installing it on the motor side of the starter like you did. Glad to hear you got it running. Make sure to take some pictures of said connectors, starter, and overall engine. Also take pictures of rubber left in the street after your first burnout.

[HRH]

Yep, have a whole list of things to do to her now that she's running well. Think I'm going to quit while I'm ahead tonight and have some victory cookies. And if only I had listened to INDY! :) It's like everyone said, it's something stupid you just overlooked. :P

 

I just dicked around with idle and timing, it's amazing how quickly she reaches temperature now. And my cheap temp guage seems to be fluffed. It reads a bit high. My electric fan wasn't kicking on and I had to go get my infrared temp gun to see what the actual temp was and it read about 10 degrees higher on the guage. Cheapy special, go figure.

[Duke]

I have been following this thread for a while and I was really feeling for you while you were having difficult times. I had a similar experience during my KA swap, but as I'm sure you are experiencing, it is sooo worth it once you get it going. Great job sticking with it.

[bilzbobaggins]

Awesome....so the yellow wire was kinda like a cold start injector...wow...congrats on the car and everything else... :D

 

jeff

[fisch]

I've been following with interest too man! But am totally unqualified to comment on the wizardry of FI. So glad you got it sorted, and eagerly await the vid!

[LenRobertson]

So now that it is finally running great, I'm going to suggest you screw it up again! The stock SX system has at least three relays, all interconnected with each other, the alternator,oil pressure sender, maybe a few other bits. It all looks needlessly complex in the wiring diagram, but the idea is to kill the fuel pump if the engine quits. I know we all laugh at "safety" crap, but this is something that might save the car (or you) from burning to the ground someday. Wiring in at least one relay through the oil pressure circuit seems like pretty cheap insurance. Or just grab the relay block from the '80 SX at P&S, since the harness already has a plug for it. I know this idea puts you at risk of a relay failure, but those things tend to last a long time, and you can always carry a spare if you are doing a competition thing.

 

Anyway, congrats on the success. When is the winter rallycross? Predictions are for a snowy winter!

 

Len

[HRH]

Yeah, I don't know about rallycross. The airport isn't that jazzed about the idea and probably isn't going to help plow this year as they need to worry about their runways. So depending on snow, it may or may not happen. We also have to have quite a few people for it not to get cancelled. Think we needed 14 both days to break even. Unfortunately not that many people want to screw around in the snow. Much less we can't afford to have someone plow us a course so it's up to us. I'm all for the snowy winter, but I'll need to find or make a cheap snowplow for the truck and do that 'cause I don't think anyone else is going to.

 

As for the fuel switch, I have a huge toggle for ECU and fuel pump easily within my reach. I know that doesn't help if I'm unconscious, but I'm not too worried about it. However, it is a good idea, and if I get everything else sorted out, I may wire that in.

 

I'll try to post a video on Sunday if I get around to it.

[wildmaninid]

Mat, trying is just setting out with the intention to fail!!

 

You will post some videos.

 

I wish i had gotten in on the ground floor of this adventure, i think i could have saved you alot of time and headaches, but hey you now have the experience, just the way i gained it.

 

Looking good all the way around, I need to get over to spokangeles some day and we can bench race. Aren't you glad i told you datsun's were the coolest all those years ago?

 

LOL

 

Congrats man, have a drink

 

Bill

[Creepy Cruiser]

Congrats Matt!

 

Now lets race!!!!

[HRH]

Haha, thanks Bill!

 

Todd, I'm all up for that. I'm curious if my newly fuel injected high-strung 20B can keep up with the torque of the KA. I'm thinking you might edge me out, but we shall see. :cool:

[Creepy Cruiser]

Get yours all dialed in and we'll set it up. It should be fun.

[wildmaninid]

I tried putting out an apb with the spokompton police regarding the future low speed race of 2 datsuns in the greater spokane area.........no one returned my call............................................

 

 

Have fun boys

Bill

[HRH]

The po po are busy chasing all the Ruskies in stolen Hondas! :D And we may have to race in snow! Finally committed to moving the battery to the rear passenger footwell. Have an aluminum plate and battery box mounted now, had to go get bulk cable at work today. Ended up needing about 83" to make the connections. Still have quite a few things to do to her.

[Creepy Cruiser]

No, no, we'll find a nice SAFE/LEGAL place to race, lol. I'm not into crashing into or killing anyone else.

 

(Now drifting a local roundabout once in a while in the middle of the night, well, maybe, lol.)

[HRH]

I know of an abandoned stretch of road in the valley, it's near the Kaiser plant. I'm sure we can find a place with no one else. If not we can go to Idaho. I know all the sheriff's deputys there. :P

[Creepy Cruiser]

Hey Matt, (and any other fairly local people), the next local Nissan/Datsun meet, is this Sat evening (the 13th) at the hot rod cafe in post falls @ 6pm. (I think Duke will post it in the local thread also.)