HELP.. electrical?

[marksktr]

so i was driving in the neighbor hood the other day and my 91 camry stalled out and wouldnt start again. right now its in my garageand were trying to figure out whats wrong.

whats happening:

we turn the key to start it, the engine cranks.. but when we let go of the key and it returns to the ON position in around 2-3 seconds it dies out. but the car WILL run if we hold the key in the START position.

My engine:

3s-fe

what we have done thus far:

-replaced (with new) and tested ignition coil
-changed (again..) plug wires and distributer-cap
-tested battery to be 12+ volts

what we THINK it may be:

ignition switch


your help is greatly appreciatd.

-mark

-o and ps.. i got a tach for when i do have this thing running (for the people that read my other most recent post)

[Doctor J]

The problem you are describing could most likely to be a fuel pump control circuit. Here is what I had wrote in my old post:
The problem sounds like fuel pump switch inside air flow meter. First, open the diagnostic box and jump the Fp and B+ terminals. Start the engine with jumper connected.If it runs normally, check connector on air flow meter. If OK, check the circuit opening relay near engine ECU. If still good,then it is possible to adjust the fuel pump switch inside air flow meter. To get access to the switch, you need to remove the black plastic cover on top of AFM.
For this case it turned out to be loose connector on AFM.

[marksktr]

jumper thing worked perfect......

the AFM conector is fine...

circuit opening relay. where is that located? i know you said by the engine ECU, but where is that? do you have a picture or link of some type to help me locate it?


and adjusting the fuel pump switch. what kind of adjustment do i need to do to make it run properly?

in my book it says about ohms resistance. and if it is not what it is supposed to be then just replace the unit as a whole. and "just replacing" the unit is kinda hard when its a $400-500 item.

thanks for the heading with the jumper. it was great to hear the engine running longer than three seconds after that whole day of buying pieces and spending all of our time acomplishing nothing.

thanks again-
-mark

[Doctor J]

The relay is located undr the engine computer (ECU).Both things are secured to the bracket behind and below ashtray.Pull the carpet on the passenger side and you will be able to see the computer connector cover and small black rectangular box under it (the relay). Download the manual from the CAMRY General discusion forum and check the relay and green wire from the relay to the air flow meter.
But first examine connector on the air flow meter. Sometimes the miniture female terminals inside the wire harnes connector side getting deformed and pushed inside, creating no contact conditions despite perfectly seated plastic piece. Also, locate thin wire (wnite w/ black trace) at the air flow meter connector (you may have to pull the rubber jacket on the back of the connector to expose the wires), and make sure that there is a continuity to the ground from its terminal)

[marksktr]

edited for further update-

so right now were almost definate that it is the circuit opening relay that is causing us the trouble.

but we are unsure about a few things-

-when the MAF sensor is not pluged in the car stays on, but does not run persay (turns off when you hit the gas)

-when the MAF sensor is plugged in the car does the same thing that it had been doing with turning off after 3 seconds.

so we looked at the inside of the circuit opening relay and it is just a capacitor and some coils. so were not sure how that works or how you can test it.

so right now were at the point where we think it is this circuit opening relay mainly because when the car is jumpered *bypassing the COR* the car runs perfectly as does the MAF. but when not jumpered theres that problem

so is there a way to test this COR or from what it sounds like should this thing just be replaced?

ill probably call around a few places tommarow for some prices (pepboys, nappa, autozone)

let me know what you think. cause im going with this COR as the problem.

thanks so much.
-mark

[Doctor J]

When the FP is jumped to B+ the fuel pump runs directly from igniton power ( main relay to be exact) so when jumper is in, both AFM and circuit opening relay are by-passed. There are two coils inside the relay, you need to check their continuity with the ohmmeter.While relay cover is out, take careful look to what spade terminals the coil lead wires are sodered and then just measure continuity between each pair. You most likely will get continuity trough the "sterter circuit" coil, and no continuity trough the "run"coil. Below there is typical relay pinout:

[marksktr]

so how do i determine if that is dead?

and is there still a possiblitlity that it isnt the relay but the MAF?

[toyomoho]

Find the service info for this year of car at the link below. Use the test procedures in the manual to troubleshoot the components.

http://oregonstate.edu/~tongt/camry

[marksktr]

not to be rude but weve read through those manuals like 5 times already.

so doc, im pretty sure im just gonna go out ahead and get the relay. at my local pepboys its a special order item and its $82.

you think is wise to just go ahead and try this?

my second option was to go to a dirt cheap self service junkrad and grab a few from whatever gen2 camrys theyve got. i can do that thursday afternoon and then we can see whats going on after that.

[Doctor J]

Personally, I am always getting parts from the junkyard.
To check the relay (if meter is not available) connect + of 9 volt battery to the B terminal and - to the FC terminal.If relay clicks, the coil is good.There are several occations,when the wire connector on the AFM was damaged or poorly seated. You can also check the AFM switch by following these steps:

• plug back circuit opening relay
• disconnect plug from air flow meter
• inside the plug, locate two gold-colored terminals next to each other at the end of terminal row
• fabricate jumper from small paper clip
• short gold terminals
• turn ignition on, do not start the engine.

Have assistant to hear if fuel pump is running.If yes, the switch inside AFM needs to be adjusted. If not;

• unplug the circuit opening relay
• with jumper in place as per part one, check continuity between FC terminal (wire side)and the ground
• if no continuity check the wire from FC to AFM and from AFM to the ground.
• if continuity is present, replace the circuit opening relay.

[marksktr]

checked the relay, and it is el deado

thank god tho.. we kinda accidently ordered the part a few hours before we found this out, so i guess we got lucky.

i got a new one just to be safe in t he future so this happening again has less of a chance.

well we should be getting the piece in friday, so ill post back letting you know how it works.

thanks-

[marksktr]

nope.

circuit opening relay is not it..

we just jumped the +b and fp terminals and drove it over to our local mechanic and told him to find out what was wrong with it, because we were fed up already

let u know what was wrong