Oldtimer- New to Nissan - w/ 1st D21 Project

[godmachine81]

Hey Guess, I'd just like to introduce myself to the forum. I just recently obtained a 1992 Nissan D21 2.4 KA24DE.

I have been an enthusiast for years with tuning ECUs on domestic vehicles, more so with Chevy, but now I am here and I am very interested in getting involved with the community. I have built OBD-1 cables for several users that have been much more than happy. I would love to do the same for these OBD1 vehicles also. I need a little more insight on the trucks though. I would really like a Pin-Out of the OBD connector inside the vehicle. I normally base my OBD-I tools off of the FT232RL chipset. I think there is a good possibility I could do the same thing to work with the nissan, and use some great software such as TunerPro RT!

Here is my other area of interest since I have owned the truck. I personally always ditch the emissions on any vehicle I own. After beingn effected over the years by faulty devices, bad intake valves from carbon buildup, lack of horsepower etc.. My main goal is to most usually compensate the emissions deletes with an improved fuel economy also. This however almost always requires a ECU Tune (Or if you know what you are doing, you can run completely open loop with the appropriate timing,engine components, etc. I do not wish to encourage anyone to break the law though. If emissions removal is illegal in your state, then please do not drive on the road with your emission-stripped vehicle!

I Have a serious question regarding these KA24e engines in the Hardbody/D21 pickup trucks though. Everywhere with details online seem to target the 240SX style intake manifold equipped on the KA24E /DE. So many of us do not have this intake. I personally do not see the great need in swapping, other than it does have a more modern look and might be more appealing to the eye. I'm sure a few more ponies can be pushed too, but these pickup trucks need much more documentation available.

The main problem I had with my D21 while removing emissions was trying to figure out where exactly each vacuum line was located unterneath the throttle body, if they all indeed did supply the same amount of vacuum to each port. I found two pages related to these vehicles online, and neither of them showed up close pics of he procedure being done. The other one was somewhat helpful in taking the posters word for that all the ports on the TB were labeled correctly. For the most part I think they were.

Here are those links in case you are wondering:
* http://www.infamousnissan.com/forum/sho ... php?t=8257 This guy followed a guide that was for a different type of vehicle, and he clearly states by showing his pics that he just sorta guessed.

* http://www.infamousnissan.com/forum/sho ... php?t=8257 This seemed to be the only source I could find the exact ports on the throttle body on our pickup trucks KA24e. This provided me with a little bit more help than just going in blind, looking at tall these 240SX vehicles with complete different emissions and complete different intake systems altogether!

Anyway, Here is what I did to my 92 D21:

1. Removed the EAI / Air Injection setup

2. Removed the BPT / EGR Solenoids

3. Unhooked vacuum to everything - EXCEPT one port. I put a T- on my brake booster port and ran it directly t to my Fuel Pressure Regulator

4 I know a lot of people say keep the Idle Air Control and the Fast Idle Control Valve - Well I didn't. Why, because unlike some of the threads targeted more toward the 'cars / 240sx' we have the opportunity to fine tune our throttle body, in a way just like a carburetor vehicle, however this also involves some very critical procedures than can leave your vehicle not running!. Why, you are saying, did I delete these!?!? Because with the proper mixture of air and the air flow / demand you can balance your fuel economy and also avoid those Rich or Lean conditions often caused by just simply 'deleting all your emissions' Think of it like fine-tuning a two-stroke engine, it has to be precise. Lucklily our trucks have this feature, most fuel-injected vehicles won't allow you to manipulate these things!

5. I also bypassed the engine coolant lines going into the throttle body used by the Fast Idle Coltrol

6. Like most people I have removed my Catalytic Converter also. The EGR Tube and the AIR Injection tubes have both been removed. I don't have any custom built manifolds or headers yet but my next step is to add my Flow Master Classic 40 Series to the pickup.


What did I not delete? I kept the SCV (Swirl Control Valve) there is absolutely no gain inj aremoving the secondary butterflies from the intake, you will lose some low-mid range torque, which I'm sure most know. But If you leave them, they stay open unelss you provide vacuum to either the SCV Solenoid Valve or the SCV Valve its self. So Why permanently remove it, when you can disable it or enable it as you please? I didn't fully get rid of the EVAP system, however I did redesign my EVAP/Purge functionality. Instead of using the Engines vacuum to draw in vapors, I don't use this method at all, I simply Keep the Charcoal filter to allow it to vent into it, but without returning those bad vapors to your engine. It also helps if you use a vented gas cap. If you are Eco-Friendly, then this method isn't going to be a good one for you because the vapors are going to end up in the atmosphere


I bought this truck in fairly bad condition, so I bought it to work on as a project only. Right now I am waiting on my front bumper from a 1997 and the Grill from a 1997 aslo. I am really needing thee plastic console/bezel that goes around the automatic shifter (the part that holds change, or other personal items also, not the actual plastic shifter indicator). I Have to repair frusted through bed on both side directly above the tires. The spots are about 8" long by about 3" think - surprising its the only rust on the body. I have already got my materials to begin the repair on that soon, if weather permits, which I highly doubt here in KY. Currenlty the truck is Red, I am really considering going all out with just a flat gray or flat black primer and then doing the interior really nice

OK OK I guess enough about me and my truck now.. I will hopefully put some pics up soon. I really wish I would have taken pics of me doing my emissions delete and my other little odds/ins as it seems quiet impossible to find ANY detailed instructions pertaining to the KA24E Pickup truck engines with the non-sports car intakes.

I'd love for anyone to point out suggestions, and I am always open for questions and by the way this forum is just spectacular! I really wish there were more people who owned these pickups willing to participate in some professional level modding/tuning so that we didn't have to pick up bits and pieces from the other vehicles that used our engine, but were made completely different!

Thanks So much guys for having me hear, look forward to the replies!


Good Luck and Enjoy your Nissan!!

[Rogue One]

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[godmachine81]

I appologize for not putting up the pics yet, I don't currently have a working digicam to take pics, and most usually when I'm working on a project I"m just not the type of person standing around with a camnera taking pics of everythiing,.. However I will upload some pics as soon as I can, and I actually do plan to make a detailed HOW-TO on the removing emissions for those users of the KA24E that isn't a 240SX or a knock off of a 240. All those d21/hardbody pickups who haven't got the 'mixed' information coming from other vehicles sharing the same engine but different controls, emissions, throttle bodies, vacuum routing, belt routing, etc. One of those guides helps with users to an extent, but for some of them it causes them to have problems because not everyone realizes that there are several different types of the same engine spread across several different vehicles.

I hope to upload some pics soon of how I did my emissions, and I will also upload general pics of my truck (I have only had it less than 2 wks now) If anyone is also interested in tuning / reading live data from your Pre-1996 Nissan/Datsun then please let me know. I'd love to get a thriving community going based on open source platforms to give each and every user the ability to view real time data, and alter it either temporarily or permanently!

Thanks for the replies guys!

[Rev_D21]

Welcome to NICO! Let's see some pics of your truck!

[godmachine81]

Here is a photo album I shared on Dropbox: https://www.dropbox.com/sc/qsslj7rssyen0nd/RmGnOShkjc

Here is a pic I took today If you don't feel like looking on dropbox:


Another today:



Engine Bay:




Not sure if I want to paint the hood to match or not. I kinda like the grey hood. I like the old style vented hood it goes well with the newer grill in my opinion. Also today I installed some of those E3 plugs. Let me tell you something about the, they have some serious kick. I can't believe a simple spark plug can make such a difference in power. I'm not sure how well they are for fuel economy, but for the past few days I have been getting a little over 30mpg with my truck.

Hope you all enjoy my pics, even if you don't its OK, at least I know I sure enjoy my truck!!

Take care all

[Rev_D21]

I like the slotted hood a lot myself. I have one on my '95 and my '91.

[Kevkev1411]

I really like the slotted hood and v grill on it. It just matches up nicely. So you have your intake cut back to the filter cover?

[Rev_D21]

No, I am running a resonator off of a 96 which eliminates the baffle box behind the driver side headlight. It's like a poor mans cold air intake using OEM parts.

[Rev_D21]

Here's the only pic I could find of it. Older pic but still relevant.

[SOHC]

Man I would love all the info you can come up with regarding an obd-1 interface. My 94 actually has a data port velcroed behind the fuse panel. According to my limited research, it isn't supposed to be there on my year model. I haven't even been able to identify the connector.

I need to pull and clean my TB and intake, and probably replace all the lines as well. So I could definitely use a step by step emission delete tutorial. I bought this truck new, 20 years ago, and the only thing I've had to do to it was replace the cooling system. The only thing that has actually failed was the water pump. It definitely deserves to have some money thrown at it.

I'm planning on installing a header in the next few weeks and I'm still uncertain if a stock egr pipe is going to work. I've been told the engine needs the gasses from the egr at idle, so I was planning on keeping it. But if that's incorrect I need to rethink my plan.

[Rev_D21]

The engine would stall out if the EGR was open at idle.

[SOHC]

Thanks for helping me get that straight! When I was told that, I assumed I was wrong about how it functioned. I know how to test it, just figured I was wrong about what was open or closed.

So, what happens to these engines when you delete the egr? Is engine knock, pre-ignition a possibility? What affect does it have on emission tests? Every header I've looked at only connects one cylinder's exhaust to the egr and it doesn't appear to be an exact fit with the stock egr pipe.

BTW, thanks for your work here rev-D21! You've got some great info published here.