I did the test according to the 1991 manual.
although i was a little confused by the fact that they have 2 "E2" wires listed in the sketch. SO i tested both "E2"'s but this is what i came up with.. With the Afm at room temp about 65-70 degrees
after checking the fsm they are all within spec except the last test to the intake air thermosensor . could this cause the bucking that i get ?

on the connector they have listed its as follows

----- ------- ------ ------- -------
THA E2 E2 VC VS

ill call the first ES pin2 and the second pin 3 as for their location in the harness

Pin 2 ---VS

344 ohms closed
76.6 ohms open

Pin 3 ----VS

344 ohms closed
80 ohms open

Pin 2 -- VC
280.2 ohms closed
280 ohms open

Pin 3 -- VC
280.3 ohms closed
280.2 ohms open

Pin 2 --THA
195.25 ohms closed
194.5 ohms open

Pin 3 ---THA
193.5 ohms closed
192.6 ohms open

im not sure about these .. does these sound right ??

 

when i tested my 91 afm, i did a volt test. i did it according to the Mitchell book. one thing you also have to check for is the smoothness of the voltage shift. what voltage its at closed, how the voltage changes while slowly pushing in the cone, then what the voltage is wide open. its been over a year since i did the test, so i dont remember specifics.
also, make sure the afm is mounted right. mine is missing a bracket and my idle used to fall because my afm wasn't mounted properly. its a long shot, just thought i'd add that.

 

Weird .. ill have to try that .. im not sure .. but does the Rx7s have a problem with afm's?? i dont know where to try next anymore .. im wondering if my engine is blown i just dont know it yet

 

my car bucked in parking lots. i told you that sob story. and, who'da thunk, my car died sometime after. still, some bucking is said-to-be normal. without knowing if the statement is true, and without knowing what 'normal bucking is,' oh, and without riding in the car; yea, its hard to say.
i dont know how common it is for the afms to have trouble. but look at TPSs, we hear of trouble with them, and when something goes wrong, people blame the TPS. why? probably because someone else had trouble and that was the problem. so you could i have one out of every who-knows with a bad TPS, but a much higher percentage of people who blame it (or whatever part). some problems i'll point to as low compression. why? the damn engine is old and the compression starts to slip for whatever reason.
i wouldnt call an engine "blown" because it bucks. maybe weak, but not blown. when it sounds like a lawnmower and doesnt go much faster, then you can call it blown.

by the way, what are your exact symptoms? maybe link the thread cause i know you talked about it somewhere else, but i dont feel like finding the thread. if you could be more specific, do so. i may not be able to help (hell i know i wont), but someone may.

 

I don't know how different the S5 AFM's are from the S4"s, but if they're fairly similar, those readings sound kinda funky...Somewhere in there you should have readings in the kilo-ohm range (IIRC, mine went from 2.5 Kohms to 6 Kohms on the door wiper arm)...If in doubt, hook that bad boy back up, put the meter on the AFM voltage signal pin of the ECU, and take her for a spin...Speaking from experience, it's much easier to make sense of the voltage input at the ECU than the resistance readings at the AFM...

 

true, the voltage out of an accesory can be perfect, but the input at the ecu could be wacked. its good to know the voltage in as many parts of the circuit as possible when narrowing down where the gremlin is.

sorry, whats IIRC? i see it everywhere. it makes me think of race tracks or race circuit and remote control cars.

 

LOL, that's what I used to think too...If I Remember Correctly, IIRC...

BTW, unless you have bad wiring (which is usually the very last thing to go bad in any circuit, not counting physical connections), the voltage output at the AFM should be EXACTLY the same as the voltage input at the ECU...It's just much easier to read everything you could possibly want to from the ECU, instead of jumping all over the engine compartment...

 

right, tis true. i guess in electrical automotive, the teacher was using connections (resistance) as an example and overdid it a little. its true, there's no connections, that i can think of, between the engine accesories and the ecu. good call.
nonetheless, i have had wires burn. i had an intermittent rear lights/parking lights problem which was a toasted red/blk (or blk/red) wire. also, i took my driver side electric window switch apart since it wasnt functioning properly and the inside had, what i guess would be, carbon spots (basically burn marks). i wish the cars came with slightly larger wires or slightly smaller currents.

 

If your wires are burning, the fuses aren't doing their job, which is to protect the wiring. Any short that's bad enough to heat-stress a wire should be blowing the fuse...Period...

 

Hey wayne and casio ,, you guys seem to know whats going on. hehe Anyway here is my problem .. i just took the car for a ride. Before this i took out the afm tested it .. and i regrounded the ecu with a nice clean ground and some 12 gauge wire. the car holds idle a little bit better . and revs a little smoother. but i still have nothing under 3 and above 5 .. and after i push the throttle past about 35% the car stumbles. last night i was driving the car and it started cutting out terribly at a light.. . i didnt touch any of the wiring.. I also checked the map sensor voltage . and check the fuel pressure regulator. put on a fuel pressure gauge. after i did all this the car started surging .. like the idle was bouncing from 1-3 grand. I switched fuel pumps. and after i did that it still surged. but its help the psi better so i kept the new one in. If you guys where having these problems what would you check ??? also i might add that when i checked the fuel pressure i didnt pull any psi at all .. could this be the problem with the upper rpms hesitation ??

 

well, i wouldnt say "oh my god, my wires are burning!" it was more of, "yea, that wire burned." and how could a fuse not do its job? they dont have expiration dates. i could double check to see that the fuses are the right amp rating, but i'm sure they are. it could be an electrical flaw (rating).
you know, i just read a paragraph on shorts and it made me wonder why the wire burnt. i cant remember if i ever had to replace the fuse. i did, once, have to replace a few fuses in my box for a still unknown reason. nothing ever happened afterwards, so i hope it was a freak occurence (though i dont necessarily believe that).
fact remains, the wire got hot enough to melt itself and cause that black (carbon?) to be on the clip, similar to my findings inside my power window switch.

 

First of all, what were the fuel pressure readings, at idle, at throttle, etc...?

You absolutely sure your TPS/ circuit is good?

What else have you done to the car recently (removed intake, messed with rat's nest, stuff like that)

 

what do you mean you took out the afm to test it? you physically detached it from your car? i remember being taught to always test accessories while they're attached to the car's electrical (but i cant for the life of me remember why). it seems reasonable to take it out to test JUST the accessory, though if it has proper voltage to it, i dont see why you would need to. also, if its attached, you can see the reading the car (ecu) (and its X year old wiring) gets.

as for fuel, i have never dealt with fuel systems. sorry. i like electrical and have a better understand after taking a course. i am by no means an expert, nor anywhere close.

okay, you have 'nothing under 3 and above 5,' what? rpm? your car doesnt run right except from about 3-5Krpm? is that pedal-dependant (how far the gas is pushed in) ?
and above about 35% the car doesn't rev smoothly. does it run rough above there, have lack of power, etc.. ?
i'm not sure what you meant by "didnt pull any psi." no PSI as in 'the fuel has NO pressure?'

 

ok ill break it down , i bought the car about 1.5 months ago. it didnt run that well and needed a clutch. so i put it in .. I just recently been able to drive the car.. as of last fri. The car sat ain the dude's yard for about a year or 2. But this is what i have done in order

Spark Plugs
Wires
Clutch,pressure plate, and lightweight fly wheel
walpro fuel pump
Evap gas vent ( vent on top of the gas tank)
fuel filter
Injector cleaner
Bonez hi flow cat
borla exhaust
I did all this while trying to get the clutch and flywheel to work .. but the car always started but once again i never drove it.

once i was able to drive it . it would idle fine. but once i pushed the gas pedal it would stumble. then i would let off and try again and it would raise. I then adjusted the Idle . didnt do anything. still bucking/stumbling. I tested the Tps. It would go from 1.8 and overload. I ordered a brand new one from mazda. put it in and get the same thing. I then did the fuel pump rewire. The new tps is working but at idle it is at 2 ohms. and at wot it has 5 ohms. I tried to adjust the tps no luck .. i can push the plate closed and it would come back to a little over 1 ohm. but once you snap the throttle it sits back at 2 ohms again. Like the return spring isnt comming back all the way or something. I also found that the whole time that the 5th or 6th port vaccum line was off. i put a hose on it . and it made the idle worse. . and made throttle response even worse. I tested the fuel pump psi .. i have 30 psi at the pump. I then tested it at the inlet right next to the oil filter. still had 30 psi. at like 3000 rpms ,(if i can get it there without stumbling) its was a little under 30 psi. After reading the haynes manual. I tested the map senor. when it was idling i gave it a wiggle test. it affected the rpms slightly. so i went to test he sensor but i didnt have a vaccum gauge. but i tested the volts .. i belive i had about 4 volts. i then tested the Fuel pressure regulator. with vaccum line on i had absolutly no pressure. revving it i had no pressure. pullling the vaccum line , no pressure. and reving it with vaccum off no pressure.. I then pulled off the line without releaving the pressure and nothing came out .. nothing sprayed .. i thought that was kinda weird. i then took the afm out of the car and tested the resistance in the meter by how the FSM described it. as of right now the car runs and idles. i have no real power through any of the rpms. I have had 2 instances where the car ran perfect and i could floor it through all rpms , but that lasted only a few minutes at a time. but now i cant put it past about 35% throttle. and the only power i do have comes from 3-5 grand. after 5 the car stumbles . like it makes a wierd sound like its getting too much air and not enough fuel. and under 3 grand the car bucks like its not getting enough gas. . this is where im at and im lost for options.. my next move was going to send out the injectors to get cleaned and tested. but im lost as to where else to look ,., thats why i was asking you guys

P.S. I also dual grounded the fuel pump (resistor was overheating) the ecu, the alternator. and the battery.

 

Damn, now that's a novel...
1) are you sure you're not flooding yourself out every time you push on the gas with that walbro pump?
2) Make sure you're totally warmed up (fast idle cam no longer holding the throttle plates open) when you adjust your TPS
3) what about the main fuel filter?

 

Im pretty sure that im not flooding the engine.. i have no gas smell , and no unburned gas that i can see. no backfiring . the car runs alot better with the walpro as opposed to the T2 pump

Hmm i believe the car was at normal operating temp when did any adjusting to the tps or idle.

I changed the main filter. and the psi difference was about 1psi or less after the filter as opposed to before

 

I just typed this in another post, have you checked/ cleaned the engine bay grounds?

 

ive done alot of them
im was searching for a decent threat on locations to do .
but basically every ground i come across i have cleaned up

 

Top of the rear rotor housing
Gang ground below the trailing coil
Tranny to firewall ground
There's also one below the intake box area, but I haven't figured out yet if it has anything to do with driveability functions (it might be the boost sensor ground, though, since it's in that area)...I'll figure it out, give me a minute

 

Nope, boost sensor gets it's ground through the ECU...
That ground up front (below the airbox) is for the front lights & a bunch of other little things

 

wow i havent done any of those yet. i cleaned up the slide terminal and the capacitor on the slave cylinder. and the one under the air box i have done. ill try the other ones tomorrow.. and ill replace the the slide terminal with a ring terminal .<-- heard that is better than the stupi slide terminal. but if you hav