Rx-7Doctor

iTrader: (13)

Last picture near the AFM you have the green connector, near that connector is the fuel pump bypass connector. It usually has a rubber boot around it and it is a 2 pin connector. Just bridge the pins turn the key and start the car.

j9fd3s

iTrader: (3)

i think, if you look in the 3rd pic, by the idle mixture adjustment screw, theres that round connector, and its hiding under that.

bliffle

I pulled the AFM to test it per the manual, and it looks good.

I figure there's a misprint in the manual because it mentions "E2 and Fc" in the text, and then E1 and Fc in the table. So I measured E1/Fc, which correlates with the table.

I still don't know where that contact pair to energize the fuel pump is. Do I have to tap into that multi-connector on the AFM somehow and jump E1 and Fc?

Can I assume the AFM is OK and put it back in?

bliffle

I put the AFM back in, but first I splayed out the connectors in that area and took a pic. The long black connector toward the right is for the AFM. The green connector and the black hooded connector (with two spade connectors in a T, like the ignitor connector) are disembodied. They are connected to nothing and nothing is in the area to connect to. Maybe they're test connectors or for equipment not in this car (AT?). Or maybe I should jumper one of those to force the fuel pump on!

Aftr replacing the AFM I tested again with the same results: runs for 10 secs and quits. When it quit I waited several secs and tried without cycling the key, i.e., just going from the RUN position to the START position, but it wouldn't start. When I recycled the key back thru OFF it started and ran 10 secs.

redfb

^^ditto i can't figure out what those two plugs are for, i think me and you are having similar problems except i don't get high revs and i can't start it up right after it dies..so you're kind of like my guinea pig haha j/k

bliffle

It might help if you detail out what happens with your car in a list. It's tedious and more work than you thought it would be, but it may be necessary. There's a lot of stuff a guy forgets or mis-remembers if you don't take notes and repeat the experiment to make sure.

I think that later tonight I'll improvise a shunt for that black connector from a pair of male spade lugs and give it a try. Sure hope I don't blow up! But if you don't hear from me again you'll know that was NOT a good experiment.

Rx-7Doctor

iTrader: (13)

Like I stated it is the 2 pin connector under the black rubber boot.

RXnos1200

iTrader: (24)

My fuel pump bypass plug with the rubber boot is right by the test plug for the TPS. The bypass plug wires that I see are; 1 red w/ yellow stripe and the other is black. Hope this helps.

bliffle

So that green boot is for the TPS monitor?

I made a shunt for the black-boot "T" connector from a pair of male spade lugs but I'm going to wait 'til morning to try it out. Don't want to be standing over my engine with the hood up and hotwire in hand at night in this neighborhood. The Police are just looking for a Crime Wave to justify their existence in Los Altos. Biggest thing we've had so far is about 3 years ago when someone actually broke into a parked car and took something. Had 4 cruisers in front of the place, maybe the entire police force. Radios squawking all night long. Big time crime hereabouts.

redfb

that brings back memories! haha sounds like some of the places i've lived too

RXnos1200

iTrader: (24)

My TPS check plug is green and is a 3 wired female plug. The fuel pump bypass plug with the boot is a 2 wired female T plug. Hope you get it worked out. ^^^^^ yup the last picture you posted.

bliffle

The fuel pump jumper didn't work.

I could hear the fuel pump running when I turned the key to ON, but it started and died after an even shorter run than before.

I had high hopes, but... I was prepared for success: I had a pic of the nice little shunt I made, you know, so I could brag on the forum. But, alas!

I may try getting an AFM off ebay or forum classifieds, but unless some OTHER function of the AFM (unknown) is causing this problem I'm not hopeful.

I'm going to run some more voltage tests using 2 or more voltmeters because I'm very suspicious of the sequence of events. When my SE dies the tach immediately goes to zero. Instantly. To me this suggests that the problem is the primary of the ignition. But I had discounted this symptom because the AFM/FP solution was easier to implement.

Meanwhile, the ECU I bought in the forum classifieds is wending it's way across the country to me so I may be able to do a replacement test with that, maybe even over the weekend. I'll try doing some multimeter tests at the ECU connectors before then.

Meanwhile I probably have to recharge my battery, and since I don't want to run an AC cord out the front I'll have to swap batteries with another car.

Probably I should remove my shunt to avoid flooding (don't need more problems!) since a function of the AFM is to cutoff the FP when no air is flowing and the engine isn't running.

With the shunt I can hear the FP and it always sounds the same, doesn't slow done and go tic-tic like some FPs I've known, so I assume it's constant displacement and excess fuel is recycled thru the return pipe to the tank. Not a bad implementation. The same system is used in hotels to provide instant hot water to all rooms: hot water constantly flows thru a circular system, unlike home hot water.

j9fd3s

iTrader: (3)

yeah maybe next check is spark, its easy, put a timing light and just start the car, if the light stops, then the engine dies, thats it. particularly the trailing

i know what you mean about cops, in sunnyvale a fender bender, will have 14 police cars, 3 fire trucks, the hazmat team, they dont DO anything except hang out, you'd think it was a high school reunion dance or something

Rx-7Doctor

iTrader: (13)

I wanted to verify this before I posted it because I could not remember.

You can unplug the connector from the AFM and the engine will still start and run. It just won't take throttle very well but will stay running without it.

Did you swap out trailing ignitors yet?

Before you swap them out try this. Start the engine with the AFM connector unplugged and see what happens. If it still dies after 10 seconds, immediately try to restart it and see if the tachometer registers or not.

RXnos1200

iTrader: (24)

Well if the fuel pump comes (with jumper ) on when the key is turned to the ON position then shut off; I would check either the fuel pump (out of the car) or check the fuel pump relay.
Also pull the jumper and turn the key to the ON position and have a friend open the flap to the AFM and see if you can hear the pump turn on. Atleast you can check to see if it works via the AFM.

redfb

if it still dies but the tach still registers what does that mean? Sorry for the post jack!

Rx-7Doctor

iTrader: (13)

Also check the air intake boot that goes from the AFM to the Throttle body. Verify that the connecting point where the clamp is and joins the 2 pieces of the boot together has not come loose.

bliffle

The big tubes in the airflow are in good shape now, tho one was sorta loose but I tightened it up.

gsl-se addict

iTrader: (3)

I would check:

- voltages at ECU..there is a diagram and listing of voltages in Haynes and the FSM
- i have a write-up in the archives on checking for ECU codes..you just make a LED test light...that can tell you if the AFM is bad or something similar

I'm wondering is something is up with the coolant temp sensor (back of waterpump). When I had a broken connection, it would be really hard to start and would only run for a short time when it did start. If you check for ECU codes, one of the possible codes is for the coolant temp sensor, so checking that could eliminate that as a possibility

With the SE, the ignition and fuel systems are intertwined as the ECU uses the signal from the ignition to fire the injectors, so if ignition (trailing) is lost, fuel will also be lost right away.

bliffle

Since I already ordered a new ECU (for $45 I can afford to use it for a replacement test, in case the old one is blown) so I decided to check the voltages on the existing ECU and I dove under the passenger side dash ready to markup a print of the connections and WHOA! No ECU in sight! Just a big ventilation motor and a big old air conditioner! Probing around with my light I can't see anything that looks like an ECU. Even on the drivers side (I looked because that's the passenger side in Japan).

Am I going blind or is it somewhere else? I had heard that the ECU is under the seat or under the floor, but I supposed that was the 12A because now I was looking at the 13B specifically.

Do I have to drop the AC assembly to find the ECU?

Is it in a different place?

I feel so dumb. this is why I didn't attempt to answer the poll in the other forum about self evaluation as a mechanic.

bliffle

Is that LED tester you put in the archive similar to the "System Checker 83" mentioned in the FSM?

gsl-se addict

iTrader: (3)

It's under the passenger floor. Pull back the carpet and you'll see a metal panel. There are 2 nuts and 2 bolts holding it down. Pull the panel and you'll see the ECU, fuel pump relay, and atmospheric pressure sensor.

Edit: Yep..just like the System Checker 83. It just doesn't have the buzzer like the Mazda part has. However for $3 instead of the $544 (last I heard for the Mazda unit)..I think we can deal without having a noise to go with the flash.

Rx-7Doctor

iTrader: (13)

Also to eliminate some of the more uncommon things. Swap out the fusible links for the injection system with some 2nd gen fuses. If you don't have some of those just transfer some of the ones for the headlamps that you know are good to the FI ones and see if there is a difference.

What is most common on the coolant temp sensor if it goes bad it will be hard to start and dump fuel but will still run.

If there was a loss of connection at the temp sensor the car would not start at all.

bliffle

I got a couple LEDs today and I'll fab the ECU code display gadget tonight, so that should point out exactly what's wrong when I test tomorrow.

bliffle

I made the LED tester, tore up the floor, attached as directed, and all I get on the LED is the ON solid light at the start. No codes. Tried it again: no codes.

I tried to start the motor and it only ran about 1 second before cutting out.

Hmmm. I had high hopes for the ECU tester.

Before I close up the floor I guess I'll check the ECU itself for voltages, per the FSM.