510 L20B EFI conversion - the project is finished!

[HRH]

EDIT: 11-4-10. PROBLEMS FIXED, READ LAST THREAD FIRST! (PAGE 18 CURRENTLY) CORRECT WIRING DIAGRAM IS BELOW.

 

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.

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Original thread starts here:

 

So I've been wanting EFI for quite a while now as the SU carbs run too rich for my taste and short of massively reworking them or buying a sidedraft weber setup, it's never going to be perfect. EFI however, can be done on the cheap side with junkyard diving.

 

About two years ago, Datzenmike sent me a bunch of 200sx fuel injection bits, and since then I've just procrastinated making the plunge. I finally decided that with the vacation from work, the 510 was going EFI. Took the 280z manifold down to Joes shop after cutting it up. Had to section a few runners for better fitment. It's not a perfect manifold, but it will flow air just fine, and that's the name of the game. Almost done with it, just need to port match the runners where it goes to the head.

 

When I pulled off the SUs, I found these nasty surprises. Overlap for one, rich as hell at idle for another. Couldn't run the carbs lean or it would detonate horribly at mid-throttle. I'm hoping the fuel injection solves a lot of this problem. Now the only question is whether to leave the deposits there and try and burn them out with running and Seafoam solvents. Or to close the valve and scrape off the mess then suck it out with the shop vac and a piece of hose. Can't figure out if it will be better to disturb it now and risk big chunks not being found, or to let it slowly dissolve in running with extra cleaners in the fuel system.

 

 

 

 

 

 

[tlap]

I had the same questions about how effective Seafoam was to disolve the carbon. After about a year of driving a newly rebuilt L20, I removed the head to replace the head gasket. There was a carbon buildup that I wanted to clean before I re-installed the head, so I soaked each combustion chamber in straight Seafoam for a week. It did VERY little. I scraped and wire brushed the carbon off by hand. I just cant see how it can effectively remove carbon build up while running. Am I missing something here?

Just my .02

[HRH]

It's just like any chemical cleaner, it mixes with the gas and contains more detergents than the normal gasoline will. For large deposits like that, water injection might be a better idea, though I've also heard of running ATF into the intake as a means of super cleaning. Blows smoke like a sonofabitch though.

 

It's a lot more effective in newer rigs with fuel injection because the engine is never subjected to such a rich condition that it piles on top of the valves like in the picture. If you don't have a big cam in your L20, you might consider trying a smaller idle jet, depending on what carb you have. I've found for the basic Weber 32/36, a .45 idle just is plenty sufficient for any 20B variety.

[inline4]

are su's worth putting on a L block?

[DISLEXICDIME]

are su's worth putting on a L block?

 

if you know how to tune them . they are the next best thing to fi

 

hrh what ecu are you going to use ? you cant run a chunky cam with the stock ecu for l/z series fi

[HRH]

Going to use the stock '80 200sx ecu. I don't even think this one has an 02 sensor, it's that basic. My Datsun guru has a few similar cars including one 13:1 LZ24 that he runs with the stock ecu, even with a big cam. No issues. Granted not exactly tuneable, but as long as it fires and doesn't knock, I'll be fine.

[nismo dr]

GM top end engine cleaner is the bees knees. Let it soak overnight, fire it up and rev the demons out. No more carbon, was told to use the GM stuff at Nissan engine school. Have used it ever since.

[HRH]

Here's a good video for you! Finally got the intake completely done, ready for install. Still need to drill the head for the new top bolt.

 

[LenRobertson]

Wow, when I saw you last week at the store and you mentioned doing FI, I didn't realize you were going to do it RIGHT NOW. Very impressive start to the project. Did the Z manifold have an EGR valve, or is it the pre-EGR version? I've read the pre ones are easier to modify, but very difficult to find. Pull n Save recently had an '82 200SX. I was there a week ago, and didn't notice if they still had it. It is still on their online inventory, but I don't know how often they update. Maybe nothing interchanges with the '80 FI system, but maybe some parts are the same if you are missing anything. It sounds like Joe has done FI conversions and can help you through it, which should make it much easier.

 

Love the vid. It sure looks like you are porting with one hand and hand holding the camera with the other. What talent! I'm really looking forward to the continuation of this project.

 

Len

[HRH]

Yeah, holding the camera with one hand, but I still had a lot of meat to grind off. Final grind was two handed very carefully. The Z manifold I cut down doesn't have an EGR port, believe it was an early 280z manifold. It's the one without the secondary torpedo tube bell in the bottom of the collector. It didn't fit just right, but is close enough for my purposes.

 

We'll see how well this system works. If it's better than the SUs I'll be perfectly happy. If not, I'll yank the whole mess and throw in a KA motor. I'm hoping it turns out good, I'm thinking the stock ECU being so basic will still perform rather well. The Z motor the system was designed for was a pretty detonation prone thing too, though with the stock cam would have had a much easier time at idle. But Joe has three or four rigs with the same setup, so it should work.

 

Going with an SR20 throttle body though. The 200sx and 280z throttle bodies are tiny.

[LenRobertson]

I'm a bit hazy on the Z manifolds. There may be more than one version without EGR. I don't know if the later EGR version can be cut to fit an L head, at least not without a huge amount of work. I suspect Joe can do it, but would prefer modding the earlier manifold.

 

I did find the "Dime Quarterly" article that originally got me enthused about FI: http://dimequarterly.tierranet.com/ Click on "Back Issues", then scroll down to Vol. I, Issue I. This is a fairly old article, so some of what he did can probably be updated.

 

But before I get carried away dreaming of FI, I just want to get my car running. I got the metric studs I was looking for here locally (after much trial and error), so the trans cross member should be okay. In hindsight, I should have done something different (as you said, have Joe make me one), but I think what I did will work. Only about another two dozen minor details and I may be running.

 

Len

[HRH]

Yeah, my first transmission crossmember in the wagon quite a few years back consisted of some square block spacers and longer bolts with relocated holes through the trans tunnel. Needless to say, I haven't repeated it. ;) As long as it works, though, who cares?

 

As it turns out, there's a common tool that works pretty well for a centering device, provided you're hogging it out to 1.524" or 38.7mm. The ping pong balls are actually 40mm, but have a little bit of squish. They were a little hard to pry out of the head after the mock up. One ball I had to cut out, damn thing got stuck!

 

 

 

[HRH]

Well just fucking great. Drilled the holes in the head incorrectly. Hogged out the manifold upper mounting holes to compensate. Worked fine until I realized I had about 1/16" sealing surface from the edge. Then reexamined the manifold and found even though we had it clamped on a head, I somehow screwed the pooch and it needs to be about an 1/8" farther apart between the halves.

 

So fuck life, fuck today, fuck cars in general. I'm going to go ride the bike. Not happy. :angry:

[datto510]

Bummer dude. :angry:

[HRH]

I checked out for an hour or so, rode the bike up some insane hills with the dog. Made me feel a whole lot better. Drove home barefoot, felt even better. Have a second plan of attack with the manifold, things aren't that bad. Still unhappy with the progress but it will continue. Just having one of those days which seems to be improving now that I kept out of the garage for a few hours. I've given myself the night off from car projects.

[motavated]

Plz finish this man. Looks promising and very very very interesting!!!

[Spedie]

Dont give up on it! This was really motivating me and getting me thinking about fuel injecting my J15.

 

Good luck!

[HRH]

Okay, better new today. After not screwing around with the car for a night, and getting up semi-early, I took the gasket and made a transfer, then started figuring things out. The 280z manifold is slightly narrower, but that's not why I was having the problem.

 

The dual SU manifold I had has the big 1.5" ports, and a much wider flange area. The manifold would have lined up correctly except on the outer intake holes, I reamed them a touch wide when I did the head. With the SU manifold, it wasn't really a problem. Not perfect port matching, but the extra flange width sealed the gap just fine.

 

The shrunk down 280z manifold also has angle cut edges instead of rounded edges, so that's why when I put it up, it only has 1/16" sealing edge, whereas if it were the SU manifold flange, it would have hidden it no problem.

 

So the good news is I only screwed up the location of the mounting bolts, but I'm taking the manifold down to Joes to have him add some material on the edges, and that should fix the problem. I'll keep you guys posted.

[mike]

Hey if you get pissed at that one and need an extra manifold Ive got a non webbed one you can have... its from a 75 or 6, egr canister on the back.

[Z Tyler Z]

Yeah, holding the camera with one hand, but I still had a lot of meat to grind off. Final grind was two handed very carefully. The Z manifold I cut down doesn't have an EGR port, believe it was an early 280z manifold. It's the one without the secondary torpedo tube bell in the bottom of the collector. It didn't fit just right, but is close enough for my purposes.

 

We'll see how well this system works. If it's better than the SUs I'll be perfectly happy. If not, I'll yank the whole mess and throw in a KA motor. I'm hoping it turns out good, I'm thinking the stock ECU being so basic will still perform rather well. The Z motor the system was designed for was a pretty detonation prone thing too, though with the stock cam would have had a much easier time at idle. But Joe has three or four rigs with the same setup, so it should work.

 

Going with an SR20 throttle body though. The 200sx and 280z throttle bodies are tiny.

 

Just use the throttle body from a Ka24e from a 240sx or 89-92 Stanza. There bolt on and 60mm compared to the stock Zs 50 mm throttle body. You'll probably need a spacer if your planning on using the stock linkage or you can always convert your dime to cable linkage. Just make sure you bore the intake to fit the new throttlebody.

What are your plans for the fuel tank? Are you already running a baffled fuel tank or some kind of fuel cell or are you just going to keep the stock tank?

 

Looks like this build is going to be pretty sweet, keep us updated.

 

LenRobertoon Posted 07 June 2010 - 07:11 PM

 

I'm a bit hazy on the Z manifolds. There may be more than one version without EGR. I don't know if the later EGR version can be cut to fit an L head, at least not without a huge amount of work. I suspect Joe can do it, but would prefer modding the earlier manifold.

Only one type, 75-76 non cali 280zs came without erg fittings both are n42 manifolds. After that all 280z and 280zxs came with erg fittings.

[HRH]

Okay, here's the progress so far. Got the manifold back, it will work this time. May need some additional grinding, but I'll figure that out tomorrow when I put it on.

 

So here's the first f up. It's not so far off enough that it will cause problems. I'm fairly confident it will still hold the manifold in place just fine. It annoys me, but if it works it's way easier than welding the head back up and re drilling, especially now that I hogged out the manifold mounting holes to accomodate the error. Still don't know how the hell I did that. :angry:

 

 

 

 

And while the intake was down there, I took the exhaust down too. The two studs have been broken for a while, was using 6mm bolts to hold them on, you can see where it was leaking. I knew it was, just hadn't gotten around to fixing it.

 

[dryheat]

Do you intend to notch the top portion of the intake ports on the head?

 

 

[HRH]

Yes, I borrowed a tool that bolts onto the injector spot where you can feed a drill bit down it at just the right angle. It won't need much seeing as the ports are so much bigger than stock, but it will still be necessary.

 

The other oddness is aftermarket injectors (the ones I got from NAPA) sit way farther back in the hole, and the end isn't plastic tipped. Not too worried about it, just slightly odd.

[HRH]

Okay, so I didn't make much progress today on the EFI, but I did find out some cool things. And my roommate and the dog and I went for a 7 mile bike ride, got a good workout in. Made it down to Pull and Slave right before they closed and got a couple throttle bodies.

 

My main issue has been finding a cheap TPS, as supposedly the only ones that work on an SR20 throttle body are cars with FWD SR20s. Haha, bullshit! I found the GA16 tps bolts right on, and is very nearly the same arrangement as an SR would be anyway. It's flipped around, not that it matters, it doesn't hit anything hanging off the edge. So that's one heck of a lot easier to find. May have to change connectors, actually pretty sure I have to, haven't checked the 200sx harness yet, but I think it's a square connector, not a rounded square like the newer three prongers.

 

The best thing is if it works, the parts availability should there be failure is much great given the number of GA16 cars vs SR20 cars.

 

 

 

 

 

And after trying to fine tweak the intake manifold for absolute straightness, I've decided I need to pick up a belt sander, so that's on tomorrow's list. There seem to be a good selection on craigslist, trying to find the longest one for the best price.

[Unclejesse88]

Check to see if the 200sx tps is a four pin. It may have an idle switch in it. If so, you may want to research the effects of using a tps with no idle switch on the 200 sx efi. I don't know how that will effect it.