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Frontier KA24DE to D21 4x4 swap. No more KAZ24.


HRH

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Something I didn't mention when I called you the other afternoon. We went to Valley P&S first and I couldn't find any early Altimas, so I asked one of the nice ladies up front if there were any in the computer. She said no, but were some North location. She asked what I was looking for and when I told her cams, she checked some interchange source on her computer. She said it shows interchange for '93 and '94. You mentioned '93-'95. So I really don't know if there is something different with '95 cams, but you might look closely (if you still want cams that is). I think the Altima we took the cam caps off of is a '95 and the other one down row A15 is a '94 so should be easy to compare.

 

If you really want better mileage, maybe Art will sell you the SD22 diesel out of his 720. :P  Of course you may have to leave for work about 20 minutes earlier to get there on time. Seriously, I think you should study up on motorcycle carbs. If I wasn't so lazy I'd be trying that myself.

 

Len

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Haha, thanks Len.  I'm actually reading up a bit on megasquirt at the moment.  I've been reticent to pull the trigger on it, but if I find everything is indeed "correct" with the factory ECU and I can't make it achieve better mileage, I may opt for a standalone system.  Getting tired of being trapped in Nissan's factory coding.   Especially when I know the motor is fine in itself, it's just the management.

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Okay, it is Sunday morning, I have a few plans in place:

 

First off, I'm going to attempt to "fix" whatever's broken.  Going to start by checking the ECU for "55" blinky lights indicating that everything is okay.  If not, we'll fix those issues.  Should everything be okay, the next thought I have is perhaps she's just going to get shitty mileage climbing up the Sunset hill every morning then fighting wind on the high plains.  I have a nasty feeling I could go to Coeur d' Alene right now and average 22 mpg on the nice flat freeway with steady load at 63 mph.  However, 17.33 is UNACCEPTABLE.  Especially when a crapbox Jeep Cherokee with a bullet-proof 4.0 liter can get 23 mpg and 18-19 in the winter.  If I can't get this right, I'm going to own a Cherokee.

 

So my plans are this in order of cheapness (money-wise and time-wise)

 

1.  Fix the existing system and make it work correctly.

2.  Try an Altima ecu if it will fit, see if that will help

3.  200sx EFI using a secondary throttle body as a giant choke unit instead of the annoying IAC valve which is just a reed and spring.  I've never liked them, they never seem to work well.

4.  Swapping an Altima or 240sx car harness in.

5.  Dual SU carbs or dual 32/36 carbs.  The one reason I don't like this is because the manifold wasn't designed for fuel.  Just air.  While it would be much easier to replicate Farmer's idea, I'm thinking about taking the manifold off, setting up in a jig, then cutting off the flanges and cutting two L16 manifolds off at the flange, then staggering them to fit.  Not sure if it will work, but I have a few extra manifolds to try.  This of course, would be expensive to have done, and then you have to buy two carbs, but it's still not that expensive.  I like the idea of motorcycle carbs, but I haven't played with them, nor gotten them.  I just calculated that every cylinder would be 600 cc, so I suppose I could hook up 4 600 cc thumper carbs and make that work.  Keep in mind this is in order of most costly.

6.  Standalone ECU such as megasquirt.  I know Icehouse will vouch for this, but I'm still intimidated.

7.  An entire 280zx motor, might mean some more custom pan work and custom core-support work, but it would be soo cool.  But it's also at the last of the list.  And then what would I do with the Frontier motor.

 

I'm still stuck with the fact that the hardbody weighs 3800 pounds without me in it.  She's a heavy pig.  The other thought I have is the EGR not being attached, perhaps missing the extra airflow from that, the ECU is running too rich?  But then, the 02 sensor should see that and compensate for the very little amount the EGR lets in.  And that's only at light load and idle, not WOT and heavy accel.

 

8.  Think I'm going to hook up a vacuum gauge and do some testing also, see if my most fuel efficient point is indeed still 2700 rpm in 5th.

2. - Altima ECU will not work. The truck KA24DE is, in fact, a SOHC block with a one-off DOHC head Nissan designed to fit the SOHC block -- if that makes sense? Therefore, right off the bat, the KA from a frontier lacks a knock sensor. Won't work.

 

3 - The IAC does absolutely nothing EXCEPT adjust idle accordingly at cold start and incase of another malfunction that would cause a high idle, or low idle for that matter. Once the engine has warmed up to operating temperature and in closed loop the IAC doesn't a thing.

 

4. - same as #2. Completely different system. Harness won't even work.

 

For the fuel mileage, we need to start by doing one thing.... and you're on the right track. Check for codes. I'm willing to bet you got a O2s issue or a coolant temp sensor. Either of these components malfunctioning won't allow the engine to get into closed loop, and in return affecting fuel mileage and runability.

 

I have a large amount of experience and knowledge with the KA, whether it being a S13, S14, D21, sohc and dohc. I'm willing to help.

 

First check codes and we'll go from there.

 

To check codes, locate your ECU.

 

Look on the side where there is a "screw" and either a red and green LED, or just a red LED bulb. 

 

Turn the key to on position, waiting approximately 2 seconds. 

 

Rotate the screw fully clockwise, wait approx 2 seconds.

 

Rotate the screw fully counter-clockwise. 

 

Count the flashes of the LED. 

 

Long flashes denote the tens, short flashes denote ones. ie;    ----   ----    -    -    -    -    -    would be code "25".

 

Let me know what you've got.

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From the info on nico club, it appeared that the Altima cams were 240/248, can't remember the lift, but I thought it was more than the trucks.

 

And yes, I know the IAC won't affect mileage, it's just annoying me and needs fixing.  Incidental that it's happening at the same time as crappy mileage.  Good call on the knock sensor, I forgot about that.  However, I think it should still run without it connected?  I remember an issues of SCC where they wrapped the knock sensor in a sock to prevent it from working while they were dinking with it.  But it was in fact hooked up, so not having the output there may be an issue.

 

mhub91, yes I know quite a bit about the KA system as well, but I'm absolutely willing to accept help!  No one ever knows it all, least of all me!

 

As for the hardbody.  Checked the codes before I started dicking with it this morning.  "55" all good.  As far as the ECU is concerned, nothing is wrong.

 

Plugged in the Altima ecu.  Ran (barely) at 300 rpm, and I dicked with the IAC trying to get it to idle to no avail.  Tried feathering the throttle, it responded very weakly.  Codes on that ecu came up as TPS sensor.  So I checked out the TPS for the Altimas which fit 91-95 240sx and 93-95 Altimas.  The wiring arrangement looks the same, but I think it's a three-position switch as opposed to a potentiometer like the D21.  The Altima/240 switch has the plate like an early 280z with a plastic cover that slips on the side.  In which case, it may operate more like the early systems but I don't know.  Going up to pull and save to grab one, though I think I have an extra in the garage, just don't remember where.

Anyway, knock sensor or not, I'm going to try and make the Altima system work if nothing else just out of curiosity.  If the appropriate tps doesn't make it runable, then I'm going back to the D21 system for now.

 

As mentioned by Icehouse, 02 sensor is suspect as the leading cause of shitty mileage.  Mine is new enough, but did make an open header trip initially, so it may be skewed.  Not enough to throw a code, but still could affect it.  Thus, I will also replace that today after I finish fiddling with the Altima ecu idea.  Coolant temp sensor is newer, replaced that with the one from the KAE that I replaced a few thousand miles ago.

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I am currently not, as people charge an arm and a leg for the 248 exh cam, considering it's a stock cam they go for ~$50. The 248 cam is only found in an S13 KA24DE. It is not found in any other application of KA, however you can use a FWD exh cam from an Altima equipped with a KA. It is a 232/248 setup too, but You have to remove 5/16" from the rear of the cam though, it's slightly too long due to the distributor being driven from the exh cam.

 

But yes, two exhaust cams is a common swap for KA. It's possible on All dohc KA's. It's rumored it helps carry power even into high rpms, as the KA is an over-square engine and loves mid range.

 

I really enjoy the KA despite that the 240sx and drift boys claim it's a boat anchor.

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Not a universal 02.  Factory 1 wire.  Actually, do you know if a three wire 02 heater element wire is always hot, or does the ecu switch it off after warm-up?  I was debating putting a three wire in to help with cold start.

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Okay, back to d21 system, truck is running.  Had to run for a few minutes to clear all the fuel shit out of it from the Altima ECU test.  Definitely didn't like that.  Going to yank the air cleaner assembly and check the throttle body for binding, etc.  I think I may switch back to the original throttle body even though there's not that much different from the 95 one.  Still, I have a new tps on that one and a new IAC for it.  May just do that to eliminate any other potential variables.  Timing is currently at 10.5-11 degrees, and that got .33 increase.  Think I'm going to run it up to 14 degrees and see if that doesn't help.  Shouldn't have any detonation problems with that.  Think the Frontier KADE is only 9.3:1, isn't it?  Anyway, I'll try that and get a new 02 then go out for some testing back up the hill today.

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matt, what year is your engine? 

 

my 2000 had the 3 wire O2, and a knock sensor on the intake side of the block. 

 

honestly, i think its the D21 system that is giving you the cruddy milage. 

 

how different is the d21 to d22 harness? 

 

while the d21 system is close, its a pre OBD2 system. im thinkin this engine is not at its full potential since it running on the single cam computer. its close, but not close enough to be efficient.

 

 

i guess if youre gonna go aftermarket computer, check out the microsquirt made by DIYautotune.

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The engine is 2002, but in reality, all it is is a 93 single cam with better head flow.  I'm with you, I think the 93 system is contributing to the shitty mileage, but I still think the damn thing can be tweaked to generate better mileage.  The o2 sensor idea intrigues me as a 3 wire o2 is more responsive quicker and will definitely help the engine go into closed loop sooner.  It's not much more for a 3 wire, and I found one for a 96-97 hardbody which would be the same realistically as the motors are the same with the exception of obdII versus I.  It's cheap enough I'm willing to hook up a heater circuit and test the theory.

 

Aftermarket ECU is definitely a good idea, but if I can make it close to what I can do with a standalone, then I'm not going to spend the money.  I'd rather tweak the existing system.

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yeah, i know what you mean. getting it working with that system would be ideal. 

 

question:

 

when your driving, do you have to give it more pedal to get it going than with the single cam? 

 

im thinkin the engine is pulling more air, and is fooling the computer. 

 

could it having a bad lean spot cause mileage to suffer?

 

might be time to put an AEM in it to see what AFRs your getting.  

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I actually have a Haltech meter.  It's not the most brilliant, it uses a 3 wire o2 and goes to a 30 led readout of lean/stoich/rich.  I may piggyback that in today and take a look.  It's less accurate than a wideband but still gives you a pretty good idea.  I'm driving it pretty much exactly like when I had the single cam.  It seems to have good pickup and I really don't have to get on it too much.

 

I would think it's getting too much air or something, but I keep going back to the fact that it's about equivalent to having a better cam in the KAE.  Which I already had a mild cam in it.  The only thing I did have that I don't now, is I ran the EGR on the KAZ24.  However, I don't think that should matter from what I've read of the system.  But perhaps it does.  I may see if I can hook it back up as well.

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Okay, here's something interesting.  EGR valve.  I started thinking and thought to myself, if exhaust gas is being reintroduced into the manifold, wouldn't that be an increase in exhaust, particularly in richness, that would then be seen by the o2 sensor and thus accordingly put less fuel in to compensate for the extra richness?  I read one article that suggest is also lowers the cylinder temperature, thus contributing to better emissions and a cooler running engine.

 

The only reason I bypassed it was because the header I bought didn't have a good egr tube connection and I knew it was going to leak.  However, since I've now gone back to the factory manifold, the EGR valve and tube will fit.  In which case, I think I'm going to hook it back up as that may well increase my mileage being this system is not the smartest.  Plus it can't hurt.

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Good reading here:

 

http://www.mpgenhance.com/replace_egr_valve_fuel_economy.html

 

I doubt it makes a difference on early 80s systems like my Maxima, but still good food for thought.  I just got back from NAPA, got a new EGR valve just because and a new o2 from a '97 hardbody and one for my current '93.  If I have enough time today I'm going to wire in the 3 wire and see what that gets me.

 

Interesting article on o2 sensors:

 

http://www.aa1car.com/library/o2sensor.htm

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Yeah.  Just ran into a snag too.  Found the egr tube isnt the same because im using the 98 manifold on the exhaust.  Hope the d21 egr tube is the same, if not going to have to do some custom pipe work.  :(

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I quote R. Lee Ermey on 1" egr tube nuts:  "Whos the twinkle-toes slimey cocksucker at Nissan who just signed his own death warrant!!??"  Fucking stupid engineers.  I have pizza coming, hopefully that will make me a little happier.

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“There are those that look at things the way they are, and ask why? I dream of things that never were, and ask why not?”
― Robert F. Kennedy, Robert Kennedy in His Own Words: The Unpublished Recollections of the Kennedy Years

 

Because I put a dohc Frontier motor in a D21 and it was much easier to make the D21 system work considering the only difference in the motors was another cam.  All the rest is standard D21.  It's no different than putting in a hi-po camshaft in the regular sohc.  I had planned on using the Frontier EFI system, but the wiring proved to be more than I could do.  Too many wires, couldn't find power, it needed to run.

 

I'm not liking the throttle body spacer to manifold gasket from fel-pro, which shows it only for 98 and up Frontier, when there is literally NO difference in manifold surface/throttle body spacer/throttle body as far as mounting is concerned.  It's 61470 FPG.  The correct gasket I can only find in the MPFI tune-up kit.  It is similar, but has a raised ring all the way around the clover leaf as opposed to the "correct" one for the Frontier which has a bigger base, and only semi-enclosed.  There are triangles in the spacer plate that interfere with the sealing edge.  To me, it seems silly.  I assume it's an update and if it were truly leaking air, I wouldn't be able to achieve a steady idle.  I don't know, I'm probably being too anal-retentive with the gasket, but it's not the same kind that came out of the factory unit, and I don't like it.  There we go.

 

She runs now, new IAC, back to original 92 throttle body.  Reset TPS within spec.  Readjusted actual throttle butterfly considering it will have more air at idle due to the head flowing better, so that got me down low enough where I could adjust with the IAC.  Right now, she seems pretty good.  Replaced the o2.  Had a little bit of a hunting idle, but seemed to have ironed that out.  Decided to leave the timing alone.

 

Hooked up the new EGR valve and custom EGR tube.  Those things are a pain in the ass to get to fit right, for the record.  Welded a section on from the old D21 pipe, finally got the leaks sealed.  Had to re-weld three spots before it would hold suction.  Anyway, it's in, new EGR should be working well.  Re-routed the vacuum lines, pretty sure it's going to work the way I have it now with the fuel pressure regulator, but going to consider re-doing them again to a different arrangement.  It's roughly correct but one line does go to a variable vacuum dingus.  However, I traced it off the original motor and it appears to be going to the same place, though the initial split is different.

 

Tomorrow I'll being testing again and seeing what we get for mileage with the EGR functional and a new o2.  Cams are unimportant at the moment until I get the mileage and idle issue solved.

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So that gasket that was bugging me.  Interestingly I found out Victor Reinz make the stamped steel with raised crush ring gaskets.  Which explains why I can get the correct gaskets in my MPFI tune up kit made by Echlin, because they're using the Victor Reinz parts.  I had to go to the competition just now to find a gasket closer than driving out to Cheney.  When I arrived at Crapozone, they had a FPG but it wasn't the stamped steel one, it was regular gasket fiber!  In the fel-pro manifold set, I found the correct cloverleaf gasket, and it too was gasket fiber.  So I think they may have had something going on with VR, or they infringed on a patent or something.  Short of it is, I thought more about it and considering I had the correct gaskets on from resealing the throttle body about 3 years back, I'm going to take it off again and use these other gaskets.  Fiber is just fine, more annoying to clean off, whereas the metal gaskets you just slide out and install new ones.  Downside with that is once you crush them, they're done.  I'll take pictures of the gaskets I speak of.

 

I also realized I was incorrect that the Frontier throttle body spacer is the same.  I got the throttle body with the motor, but NOT the spacer plate.  Consequently, I had a 95 and 93 spacer plate.  So that would explain why the sealing ring goes through the triangle cut out, thus creating potential for a slight vacuum leak.  My theory is when it gets hot from running, it leaks ever so slightly, which would account for my 1500 rpm idle issue.  Didn't see that the first time.  The other potential for crappy mileage is of course the air leak.  It ran quite well, so maybe it has nothing to do with it.  Or it was just so very slight I didn't notice it.

 

Off to yank the throttle body and re-seal!  I'll keep you guys posted.

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