Terrys87

iTrader: (1)

Mine was the "Y" connectors in the harness. Check your grounds as well. On #282 are all of the checks I went thru.

Link...https://www.yotatech.com/forums/f199...6/index12.html

BlindfoldMemphis

You changed the afm?

Have you checked that there is no air coming in after the sensor?

I am like 90% sure air is getting in the air intake somewhere after that sensor ...

happened to me once i jerked the truck and the hose came off of the air box.
Just try,.

kushiel

Yes, there is a new AFM. I'll double check the hoses.

Just check STA-E1 on the ECU. No voltage when key is turned to start.

Checked the voltage at the injectors with the key in the ON position. Nothing there either.

kushiel

Looks like E1 talks to the air valve and O2 sensors?

kushiel

Checked and cleaned the 4 grounds.

The aux fuel injector is getting power and fuel.

The main fuel injectors still don't have current at them when starting the 4runner.

The AFM flap isn't making noise on startup.

Fuel pump works fine.

kushiel

So we worked on tracking down the 0V on STA-E1 using the flowcharts in the FSM

Checked the starter (all good)
Checked wiring from ECU to ST - good there
Checked wiring between ECU E1 and body ground - good there too
Check the crimps that we replaced in the main harness - good

So that left us at try a new ECU. So I put another ECU in and got the exact same results. No voltage at STA-E1 and of course the 4runner wouldn't start.

I did notice some corrosion (a little green stuff) on the small wire that connects the starter to the ECU. I'll clean this up later in the week.

I am going to check Vc-E2 and Vs-E2 as well.

After I check Vc-E2 and Vs-E2 I will post a full summary of everything we've done so far.

kushiel

SUMMARY

This project started 8 months or so ago so here is where I am at. At various times the 4runner was drivable. We took it out for a highway spin (~1 hour) and that's when the big problems started.

The following day the 4runner wouldn't start. I checked connections, grounds relays, and switches. Everything checked out. Several weeks went by and I went out to try and start it again. It came to life. It was very rough, stuttering and loping, and generally not doing so well. The following months were spent trying to track this problem down as time permitted. Figure out it was the idle air mixture screw. The 4runner ran fine for a few days once we adjusted the screw, put in a new TPS, and made a few other adjustments. We drove it around the neighborhood for the day. The AFM was making loud flapping noises.

The next day I went to start it and nothing happened. Well, the fuel pump was on, we had power, the starter worked.

After asking on here and getting lots of help this is where I am at (mostly confused now)



MAIN FUEL INJECTORS are not getting power (light bulb test)
Went through the wiring harness (which we had rewired before) all good there, aux fuel injector works fine, we have fuel pressure, and a new fuel filter

ECU STA-E1 is reading 0
Went through the checklist on this too. All the wires passed visual inspection and volt meter test. Also tried a new ECU. No change.

AFM
ECU Vc-E2 is reading 1.84 (should be 6-10)
ECU Vs-E2 plate open is reading 2.51 (should be 5-10)
The AFM passes both it's static and dynamic tests. I also swapped in a different AFM same result.

WIRING HARNESS
I had a friendly electrician friend go through and rewire all the troublespots about 7 months ago. It's still holding up.

O2 SENSOR
Replaced the old one

SWITCHES, RELAYS, and FUSES
Checked and doubled checked most of these. Everything looks good.

DIZZY
There air gap is larger then it should be which I think explains why it was hard to start but that shouldn't prevent starting? Also checked the coil which was fine.

IGNITOR
Replaced the ignitor coil with a new one. Did the spark test and that was good

SPARK PLUGS
Put new ones in 200 miles ago. Checked with the lightbulb test. All good.

GROUNDS
Cleaned and reattached all the ground according to Terrys87 photos

FUEL PUMP
Put a new one in 7 months ago. This one still works and turns on when it's supposed to.

ECU
Tried two different ECUs just to see what would happen. Nothing changed. Still no start.

TO DO
New Dizzy cap and rotor
Check the driver side main fuse box (fuses are fine, need to check the connectors)

Any other suggestions?

Thanks so far for all the help, links, photos, and diagrams.

kushiel

I reset the the air gap in the dizzy to be where it's supposed to.
Also replaced the 80A fuse on the passenger side (it was kinda rough looking)
Clean the ground and connector on the starter.
Charged the battery up.
Check the Starter Relay, it's ok.


We ended up with the same behavior. The starter goes just fine but nothing but the engine doesn't turn over.

I checked the wire at the starter (not the big one) and we have no voltage coming through it when the key is in the start position. ECU still reads 0V at STA-E1. So same problem.

We traced the the wires back to the ignition switch. At the switch we have power going in and out. So the switch looks ok.

Follow the ignition switch wires into the dash. Checked the connector at the base of the steering column, good there. Traced the wires up into the dash. Everything looked fine.

We checked for continuity between the ST1 wire (ignition switch) to the ECU STA. We ended up with 27 Ohms which is way to high.

So what we are trying to figure out is what's in between the ignition switch and ECU.

So that's where we are at. Currently hunting for a good wiring diagram before we poke around some more.

my 75 toyota

Wait you dont mean it wont start but it wont crank. Which are 2 differ thinks. Ok so is it a automatic or a straight could be the clutch switch or the neutral safety switch

kushiel

@my 75
Manual trans.


Cranks but doesn't start.

Clutch switch checks out.
Just wired around the clutch start switch. No start.

No voltage at Sta to E1. We rewired from the starter to the ECU. We get voltage at the wire but no start.

That's what we've done this morning. Taking a break trying to figure our next move.

my 75 toyota

will you email me at amd4me@suddenlink.net

kushiel

Finally got some time back under the hood. Only had a few hours today.

Rewired the joins on the wiring harness to the fuel injectors.
Now we have weak power getting to all the fuel injectors. The light bulb comes on real dim. Suspecting the solenoid resistor. I need to find one that I know is working.

Ever so often we get a backfire.

Smell fuel in the engine area, not a lot.

Check engines codes are all good.

We tried to push start it to bypass the whole starter thing but nothing happen.

Checked the dizzy to make it lines up correctly when we turn the engine.

Checked the compression through the spark plug holes.

So we moved a little bit forward. But we still aren't up and running.

I'll get some pictures posted of the 4runner soon. I have next weekend set aside for tracking down a working solenoid and doing some bodywork as well.

kushiel

Updates:
Cleaned up two of the engine block grounds which were messy.

Spent part of the afternoon chasing down the Starter Switch - Starter Relay - Starter - ECU connections. All those check out fine. Also checked to make sure the starter actually works. Check the Clutch Start and Clutch cancel.

I took the starter relay apart and cleaned it. Verified that it works as well.

Here is where the odd things are happening:

At the ECU we still get:
STA-E1 = 0 at Ig on, which is not good

The injector wires on the ECU check out (#10,#20, and their grounds) but the light bulb at the injectors is very weak.

We plugged in the light bulb into the #1 injector and then grounded the other end to the battery. When we start the car it lights up. Checked the current in the same manner and get 12V coming across.

So there is something goofy going on with the voltage across the ECU but not really sure what. So according to the ECU measurements we are getting enough current but the injectors don't seem to be getting enough current.

leetom101

Clean the ground contacts.

kushiel

Cleaned the last ground. Still had the same issue with the starter going but no to low power going to the injectors.

Put a new fuel filter in as well.

Did Rad4Runner's work around for the wiring flaw at the starter relay. Same issue. Starter goes but no power to the injectors.

Cleared the STA-E1 error on the ECU. I forgot the plug the air valve sensor back in. Fixed that, but that didn't change anything.

Started over at the solenoid resistor. Measured in at 2.8 Ohms. Put the light bulb in at the injectors and no light on start.

Moved down from injector 1 to the first join. We attached the bulb from White-red to Yellow we have no light with the ig on and with the ig start. But we get a light from Y to ground and White-red to ground. Tomorrow I am going to go through with the light bulb (and volt meter) at various places on the harness to see where we have current.

Swapped out ECU's just to check and that didn't help or change the behavior of the light bulb test.

Any suggestions? I am trying to check the 4runner up and solid before January since that is when I have my first big field expedition. Also I am trying to avoid taking it in to a mechanic both for money reasons and I need the experience to repair this thing!
Thanks again for everyone's help so far.

ara

kushiel

Spent about 6 hours on the 4runner today. Did some cleaning on it too.

Poking around in the ECU
IDL-E2 with the throttle open was reading 0 V
VTA-E2 with the throttle open was reading 0 V

So we figure out pretty quickly that the new TPS was out of position. And it was. Repositioned and checked the ECU again.

All the ECU checks that we can make pass now.

And the starter turns put nothing else happens, mostly. Ever once in awhile the cylinders will fire but it's a rare thing. So we still aren't up and running but we've solved several problems but end up at the same point. I have time next Saturday to go fiddle around with it again.

Recap for anyone new reading:
We were up and running for a few months. I was driving around town and on the freeways up to 55 mph with little problems. We had this issue of it being hard to start but usually on the third try it would go. We also had trouble with the idle loping.

I took it out for a highway spin after we tinkered with it again. Up to 65 mph for about 30 mins and then came back home. I went to start it the next day and the starter tunred but that was it. Same sorry for almost 2 months until I put a new TPS in. The 4runner came to life and I drove down to my sisters. The following day it didn't start. So it sat for awhile and my sister boyfriend (electrician and mech.) fiddle around with it and got it running. We figure out the throttle body screw was causing the engine to lope. We readjust and it ran somewhat. But the following day it won't fire up.

That's where we have been for the past several months.

Bullet22r

i know this doesn't go with your problems but, have you checked the air mass flow sensor?

rokblok

iTrader: (1)

Seems as though, from what I can gather from reading your post, that you seem to have insufficient ground. You have the power, but without a ground, your injectors won't work properly. Have you tried temporarily either giving straight battery power(or ground) to your injectors? I'm not sure if the ECU supplies the ground or the power. Maybe there is a body ground off? Engine to frame ground? Or frame to battery? I'm just throwing out ideas.

Find out if the ECU supplies positive or negative for the injectors. The maybe you an temporarily supply the other? Maybe it'll get you heading in the right direction?

kushiel

@Bullet22r
I checked the AFM by way of the ECU. I need to check the AFM directly. We put a "new" one on awhile back that got us up and running. The old one had a crappy temp. sensor and something else wrong.

I need to recheck the new one.

@rokblok

We cleaned all the ground up until the shined the other day. I put the volt meter on the wire harness where the injectors split. We get 12-ish V coming through but when we start it doesn't go to 0! It sits around 6 V. I thought that the voltage had to go to 0 for the injectors to work correctly.

I'll recheck the grounds again tomorrow afternoon.

Thanks for suggestions!
ara

Bullet22r

odd question but are their any mice around your area? maybe one may have chewed something in the harness, also do you think its the injectors themselves are you getting fuel? checked the fuel pump or maybe even the fuel lines are clogged. I'm just throwing suggestions as often random things remind me of other things, i know im pretty weird.
hope you get it figured out soon