why did they use an AFM?
01-08-2008, 12:36 AM
#1
eff good grammar
Thread Starter
Join Date: Dec 2007
Location: Deadford OR
Posts: 1,578
why did they use an AFM?
alright i am bored, and i was thinkin, why the heck did they use the AFM?
mas air flow sensors were arround why didnt they use one? and this whole trap door, carbon tracks, air temp sensor, adjustment screw stuff is nutty! it seems with an AFM you cant do as much, mabe its better with a turbo one? i donno.
it just seems stupid.
no nothings wrong with mine its just in the way, its stupid and its huge.
why does it have a door? i mean it has a TPS so is the door the measuring device for the air flow when it moves the tabs on the track?
older toyotas have the same thing, i mean exactly the same. are there any other cars that use the same meter?
mas air flow sensors were arround why didnt they use one? and this whole trap door, carbon tracks, air temp sensor, adjustment screw stuff is nutty! it seems with an AFM you cant do as much, mabe its better with a turbo one? i donno.
it just seems stupid.
no nothings wrong with mine its just in the way, its stupid and its huge.
why does it have a door? i mean it has a TPS so is the door the measuring device for the air flow when it moves the tabs on the track?
older toyotas have the same thing, i mean exactly the same. are there any other cars that use the same meter?
01-08-2008, 06:42 AM
#2
It's actually a very good & simple sensor. It's more tunable than a MAF, though it does have it's negatives. Most Euro & Japanese engines used them in the 70's & 80's when EFI was barely becoming mainstream.
Don't be hating on something you don't know about.
Don't be hating on something you don't know about.
01-08-2008, 09:23 PM
#10
NisTuner
Join Date: Sep 2005
Location: Cleveland, Ohio
Posts: 2,800
The AFM isn't that bad. The good thing about it was the fact that you could adjust it so easily to richen/lean your mixture. I believe you can do it with a MAF. The primary reason the AFMs have so many more problems is because of the moving parts, but upgrade to the Z31 ECU/MAF. It saves space, it's super easy if you have a turbo car, and power deliver, etc is smoother and the car runs alot nicer.
01-08-2008, 10:09 PM
#11
Head Muckraker
Join Date: Oct 2001
Location: Bay Area
Posts: 9,221
The creation of a "budget" or "affordable" sports car for the "masses" creates
a necessity of compromise. The Bosch K-Jetronic fuel injection was a proven/reliable system with over 5 years of development and refinement in the Z cars from 1973 when initial engineering began to the 1978 introduction of the 1979 model year 280ZX. This allowed them to get a reasonable amount of power with little "re-engineering" in an already extremely solid platform, thus, making them affordable to people who otherwise wouldn't have been able to buy one. With the "upscale" 300ZX, the additional engineering and production changes could be passed on to the new "more financially comfortable" Grand Touring segment of the buying public. You'll also note the significant increase in base price from the 1983 280ZX to the 1984 300ZX. Obviously a result of the massive re-design where the FI technology was only a small part of the total re-tooling cost.
a necessity of compromise. The Bosch K-Jetronic fuel injection was a proven/reliable system with over 5 years of development and refinement in the Z cars from 1973 when initial engineering began to the 1978 introduction of the 1979 model year 280ZX. This allowed them to get a reasonable amount of power with little "re-engineering" in an already extremely solid platform, thus, making them affordable to people who otherwise wouldn't have been able to buy one. With the "upscale" 300ZX, the additional engineering and production changes could be passed on to the new "more financially comfortable" Grand Touring segment of the buying public. You'll also note the significant increase in base price from the 1983 280ZX to the 1984 300ZX. Obviously a result of the massive re-design where the FI technology was only a small part of the total re-tooling cost.
Originally Posted by Niku-Sama
alright i am bored, and i was thinkin, why the heck did they use the AFM?
mas air flow sensors were arround why didnt they use one? and this whole trap door, carbon tracks, air temp sensor, adjustment screw stuff is nutty! it seems with an AFM you cant do as much, mabe its better with a turbo one? i donno.
it just seems stupid.
no nothings wrong with mine its just in the way, its stupid and its huge.
why does it have a door? i mean it has a TPS so is the door the measuring device for the air flow when it moves the tabs on the track?
older toyotas have the same thing, i mean exactly the same. are there any other cars that use the same meter?
mas air flow sensors were arround why didnt they use one? and this whole trap door, carbon tracks, air temp sensor, adjustment screw stuff is nutty! it seems with an AFM you cant do as much, mabe its better with a turbo one? i donno.
it just seems stupid.
no nothings wrong with mine its just in the way, its stupid and its huge.
why does it have a door? i mean it has a TPS so is the door the measuring device for the air flow when it moves the tabs on the track?
older toyotas have the same thing, i mean exactly the same. are there any other cars that use the same meter?
Last edited by lww; 01-09-2008 at 07:00 PM.
01-09-2008, 08:49 AM
#13
Originally Posted by vrocious
i'd love to do the z31 swap. when someone does a more detailed writeup and i hear thats peoples are all up and running fine i'l give it a collage try
01-09-2008, 11:30 AM
#14
Registered User
Join Date: Mar 2003
Location: WA
Posts: 373
Originally Posted by lww
...The Bosch K-Jetronic fuel injection was a proven/reliable system with over 5 years of development and refinement in the Z cars from 1973 when initial engineering began to the 1978 introduction of the 1979 model year 280ZX....
01-09-2008, 07:03 PM
#17
Head Muckraker
Join Date: Oct 2001
Location: Bay Area
Posts: 9,221
Originally Posted by FubarI33t
Early 80's inline 6 BMW's had the AFM. Same bigg owgly thing as us. Hell same plug too. As there injectors are interchangeable with us.
01-09-2008, 08:03 PM
#18
Originally Posted by lww
Actually, that was a common "cheat" in SCCA "stock" racing during the 80's since the BMW model had a larger throat but the same size housing as the 280ZX...
01-10-2008, 06:51 AM
#20
Originally Posted by Niku-Sama
did my thread spawn another parts swap demon with a BMW?
01-10-2008, 09:27 AM
#22
Registered User
Join Date: Aug 2007
Location: Perth, Australia
Posts: 199
Originally Posted by NismoPick
eh? There's already been several detailed write ups.
1. I assume no liability for any problems stemming from this.
2. You're on your own passing smog.
3. Get a NA z31 harness, CAS Wheel, coil, Ignition module, fuel pressure solenoid and EGR solenoid. Get the boost sensor and vehicle speed sensor as well. Get anything else connected to the harness including the connector the goes to the chassis harness. It depends on the year whether you will need these last two or not. Dont forget to get a FSM for the year Z31 you just stripped.
4. Get a s130 turbo distributor and oil pump driveshaft. The shaft is available from Courtesy part no. p8000-15040 they call it a spindle.
5. swap dizz. and shaft. at TDC the flat edge of the shaft should point at 11:30, or just to the right of the upper hold down bolt hole. It's a big help to have a helper for this.
6. Determine if you will need to use dropping resistors or not. If you do, you're on your own.
7.Spend hours pouring over diagrams. You've got to run wires from the right side of the engine compartment to the chassis harness connector on the ECU harness You, ve got to re use or re make the ignition wiring in the left fender. I ran new fuel pump wires and used a seperate relay so I didnt have to hack the stock wiring should I ever have to put the old harness back in.
8. Mounting the MAF is up to you. I made a new intake tube from an old intercooler pipe and put the bungs for the air regulator and idle valve in it. I then used some silicone couplers to join it all together. Don't do this until you mount the dizz, cuz its a lot bigger than the stocker.
9. I used the z31 solenoid valves to control the FPR and EGR valves, thus eliminating all those old vacuum valves and hoses.
10. the VSS on analog gauges cars is just a grounding switch apparently, so I think you can use the setup in the 280 speedo provided that your car had cruise control. This is just speculation however.
11. I know Im missing a lot of stuff, but this should get you started. I work on worse crap than this for a living (garbage trucks) so a 1'' diameter bundle of wires and four or five different wiring diagrams wont slow me down much, specially when its not covered in old diapers and broken glass. Feel free to ask questions and please gain a thorough understanding of whats going on with the ECCS before you start cutting.
like i said i'm not overly confident with that sorta thing but if someone puts up photos of a build process so i can reference it to, like the afm cleanout thread then i'l give it a go.
even with a better efi system of a e30 wouldnt the limiting factor still be the ecu itself? or are you planning on taking that too or just looking to clean it all up?
01-10-2008, 09:37 AM
#23
For the n/a yes, Jmmorriso was the first to put together a "how to" for the n/a... but there is a lot of useful info from the turbo swaps as well:
The original Z31 ecu swap "how to" http://forums.hybridz.org/showthread.php?t=91250
https://www.zdriver.com/forums/showt...highlight=z31t
https://www.zdriver.com/forums/showt...highlight=z31t
https://www.zdriver.com/forums/showt...highlight=z31t
https://www.zdriver.com/forums/showt...highlight=z31t
The original Z31 ecu swap "how to" http://forums.hybridz.org/showthread.php?t=91250
https://www.zdriver.com/forums/showt...highlight=z31t
https://www.zdriver.com/forums/showt...highlight=z31t
https://www.zdriver.com/forums/showt...highlight=z31t
https://www.zdriver.com/forums/showt...highlight=z31t
01-10-2008, 09:42 AM
#24
Originally Posted by vrocious
even with a better efi system of a e30 wouldnt the limiting factor still be the ecu itself? or are you planning on taking that too or just looking to clean it all up?
