rubronthroad

zerokelvin

So I've got the fuel pump situation figured out. I thought mine was operating incorrectly, I was wrong. Initially it would turn on when the key was in the ON/RUN position and continuously run (I was told it was NOT supposed to do that). I replaced the fuel pressure regulator which was bad (the diaphragm failed) and sending basically all the fuel in the rail back to the fuel tank. After I replaced this part the fuel pump came on in the ON/RUN position ONLY to pressurize the system. After that it does not come on, so I thought it was broke... it's not. It's operating as intended. Checked voltage in the ON position and it reads 0V. When I start cranking, it's reading 11.4V. I could run a wire and a switch but it's working correctly so no need. Tested my original AFM today correctly, I did it wrong the first time.... I'm new to DMM's. It's bad 100%, failing many tests. The new AFM I have tests correctly across the board so we're good there. I sprayed brake cleaner in the plenum and it started then died when I returned the key to the ON/RUN position. Going to trace back the ignition switch wires till I find the problem. I don't understand why it won't start. It has fuel, it has spark, intake is getting air (verified by vacuum lines and observing AFK door pushing in). Still seems something with all the safety equipment/wiring is preventing it from running.

akwheeler

there are two ignition contacts on your key switch, one when you are cranking and one when you let off and leave it in run. Most vehicles have two separate ignition circuits also so even if you are still getting spark the fuel injectors are probably fired by a different ignition circuit if I remember right. the wiring diagram is your friend.
Oh, and don't use brake clean, they make starting fluid too.

zerokelvin

Brake cleaner is actually better than starting fluid. Starter fluid vaporizes almost immediately and is used best in "cold" conditions to help start an engine. Brake cleaner will pool and vaporize slower, which will mimic correct fuel air mixture and burn better and for a longer duration. This information came from an expert engine builder/mechanic/tuner.

akwheeler

Your truck, your expert, your sensors, your cat, your call. I'll stick to starting fluid, I never needed a "pool" of fluid to tell me if I have spark or not or even to get a stubborn motor running.

zerokelvin

Sure. Not saying starter fluid won't work... I did that too. It fired a few times then died. The brake cleaner started better, ran longer. I only did the spray test AFTER testing spark with test lights. I knew I had spark, the question was whether I was getting fuel or not. Anyhow, thanks for the input. I'll update when something changes

Phear

zerokelvin

Thanks Phear! I'll check out your post and see if someone wrote something in there I haven't tried yet. I also replaced my fuel pressure regulator. The diaphragm was bad and just DUMPING gas back into the tank and wouldn't hold pressure. Put the new one in and it fixed two problems I was having (or I thought was a problem). Fuel pump was constantly running in the ON/RUN key position and I was told it's not supposed to do that.... well it will do it if the FPR is dumping all the gas back into the tank because the FP wants to pressurize the rail... Now it doesn't turn on in the ON/RUN position and I'm getting the correct voltage in the cranking position out of the FP. My issue is somewhere in this convoluted mess of safety features they added to the wiring system. I was able to get it to start today, but died shortly after... by spraying brake cleaner in the plenum. Seems like I'm back to what seems like the issue from 3 weeks ago.... something is killing ignition. I'm currently looking into the ignition switch wires, power sending wires and that side of the truck's wiring harness. I also realized that the timing could be slightly off... even though I octavian checked it lol. I'm getting fuel, spark and air and since it's a new rebuilt, I imagine the compression is fine. I'm going to check that tomorrow as well.... so it SHOULD run, but it's not >.<

RAD4Runner

The FP is not smart; I am not aware of anything that will make the FP want to pressurize the rail. Unless the 1985 fuel pump circuit is different from 1986-1988, these are the only things that will make FP run:
1) FP to B+
2) One coil of C.O.R. when ign sw is in START / CRANK position.
3) The other coil of C.O.R. when airflow opens AFM flap.

I don't remember if you said you hear anything click on or off behind the glove compartment: Click ON when you crank, click off when you release ignition key and causes combustion to stop.

zerokelvin

I used the word "want" a little too loosely perhaps. The FP WAS turning on and staying on with the key in the ON/RUN position. Fuel was literally pouring back into the gas tank during this time. After I replaced the fuel pressure regulator because it was not holding pressure withing spec (38-44 psi), the FP does NOT turn on with the key in the ON/RUN position. I am not certain, but I was told by a man that lives in Georgia that AFTER '85, they made many changes to the 1st gen runners (he was a mechanic for toyota from 1981-2000 and worked almost exclusively on these "old" trucks). I have tried to get him to come out and help me get it running, but it's a 3 hour drive one way... think I'd have to offer him some real cash. I also went to office depot and printed out 1025 pages.... the FSM! Reading through it now. It seems that this convoluted electrical system has all these "hand shakes" that need to happen in order for it to run. I am very curious about this IGF (Ignition Verification Signal) to the ECU. If the ECU is not getting this... it won't even start. Could be the issue among many possibilities.

zerokelvin

Might have made some progress here, still need some help with it. The wiring for this system is bonkers. So looking at the IGF signal to ECU from the igniter (black wire with white stripe) tested at 10V with the key in the ON/RUN position. That wire... whatever it's called that plugged into the igniter and runs all the way across the engine bay to the wiring harness has THREE wires. B/r, B/y and B/w. I read that ALL THREE should have power with the key in the ON/RUN position. The B/r tested at 12.7V, the B/w tested at 10V, the B/y tested at .07V or NO POWER. I looked at the ECU and found a B/y wire... the only one. I looked at a pinout and it shows this B/y wire to be the "STA" (starter switch)... which has no power. I'm going to see if it has power at the ECU location and that should tell me if there is a problem with the wire somewhere down the line. IF it has no power at the ECU, what does that mean? Will the "STA" wire to the igniter keep the truck from running if it doesn't have power? As comprehensive as this FSM is, it doesn't explain what various outcomes means... it mostly reads, "if there is a problem (i.e. tests bad, etc), REPLACE the part lol. Please advise, thanks.

zerokelvin

OK, tested for power at the ECU in the B/y pin, tested .07V. I put in my spare ECU, tested same pin, reads .07V. What does that mean? ECU is not supplying power to "STA" wire....? Both ECU's bad? Should I look at something else because they are BOTH not getting power at the "STA" pin? Thanks.

zerokelvin

Still haven't found any information on the "STA" pin on the ECU and IF it is supposed to have power at ANY point/s during ignition or running. I did conduct an interesting test today... to try and test the igniter, as there is no way to test this device according to the FSM. What I did was unplugged the distributor wire that goes to the igniter and plugged it into another distributor I have (this is not connected to the engine block). Took the cap off the new distributor still connect to the block and installed it on the other distributor. Put spark test lights on all four spark plugs. Turned the key to the ON/RUN position. Turned the distrubutor (the one free floating not attached to the engine) clockwise and saw all of the test lights lighting up in the correct firing order and in a static pattern according to my spinning speed. I guess this means the igniter is working. I don't know why Toyota calls this thing an "igniter".... it actually works this way: Engine is cranking, starting, running, etc and sends a signal from the distributor to the "igniter", then the "igniter" sends that signal to the ECU which then sends a signal BACK to the "igniter" which tells the coil to ground and release spark (this sequence happens very rapidly, almost instantaneously). So the "igniter" doesn't IGNITE anything... it's more of a signal transferring device. Anyhow, would love to know how the B/y wire works when operating correctly, if and when it should have any power (in Volts) during any part of starting, ignition and running, etc.

zerokelvin

OOOOOKAY. Problems located. RAD4Runner told me to check the crimps at the injector wiring junctions... so I did. They were horribly corroded and in terrible shape. I also cranked the engine (before I took everything apart to get the harness out) and used a mechanics stethoscope to listen to the injectors while cranking... listened to all four, no clicking... no fuel. I'm going to cut out all the bad junctions, solder the wires back together, shrink wrap those sections as well as the rest of the loom in a different configuration. There are MANY wires that don't even need to be in that loom, meaning they can be routed another way OUT of the loom. I should be able to do all the repairs and reinstall everything tomorrow and see if it starts. Take a look at the pics for reference, I'm pretty sure this is the problem keeping my engine from running for the last month. I should have looked at the harness as the first step. Looking back, I now realize that the ONLY wiring that really moved at all was the engine wiring harness, when I took everything apart for the rebuild. Worked fine before rebuild, but 33 year old harness getting moved around a whole bunch in the process finally took it's tole.

zerokelvin

pics cont.

RAD4Runner

Hi zerokelvin,
ConnectorPin numbering from 1988 22RE is attached (Pls double-check your EWD or FSM if you have one).
Picture shows white-red and white-green ECU-injector wires. Is that correct? On 1986-1988 they're W-R and W.
You should also be able to physically trace them end to end while you have harness out.
Also, while you're in there, if you have access to the temp gage sender(s) I suggest you unscrew them and clean mounting threads both sides.

zerokelvin

Thanks for the diagram RAD. Didn't know L stands for BLUE.... never seen that in my life. Have seen many many times elsewhere when colors are designated by letter that U is used for BLUE pretty much always, thanks Toyota =] I found a pinout diagram for the ECU plugs, with no colors of course, just unit/wire/pin/connection names. Finished soldering the handful of junctions which were ALL corroded to some degree and shrink wrapped them. I also found out that soldering is a pain in the ass... AND I'm terrible at it =]. Tested the entire harness for continuity and every connector/wire/etc gave tone \o/ so we've got a good harness now. I'm redesigning how the harness is segregated as about HALF the wires in that fat loom don't need to be there and could be routed MUCH better many ways. Problem is I can't finish it because there are 5 plugs which I don't know specifically which socket they go in. I know the 5 locations of the sockets; VSV, CSI, back of the unit under the throttle body with many hoses going into it, and two go up front under the TPS. Two of the plugs are connected by a GREEN wire with black wires on the 2nd pins. One of them has a blue wire... anyhow, wish I knew specifically where they go so I can bundle the wires efficiently. I checked the wiring diagram and nothing is matching.... super pissed. Would have been easy to just put a 1 on the plug mold and a 1 on the socket mold, then 2 2, 3 3, etc.... thanks Toyota. I'm sure all the builders back in the day knew this stuff by memory by wire color... however I don't and that sucks. If anyone knows where these 5 plugs go specifically by wire color or any other means, please let me know. Thanks.

Oh, RAD... Yes the wires going to ECU from injectors are W-r, W-g. These all come together at that horrible junction/crimp and lead all the way back on two solid WHITE wires to No. 10 and No. 20 on the ECU plugs/pins.

zerokelvin

So I rebuilt the entire wiring harness. Fixed all the corroded junctions, cleaned it up and re-wrapped it so it was easier to work with and plug when it needed to go. Here's a pic of the harness. Tested it after completion for continuity and every single wire toned out good. Put everything back together. Did a quick check of all the fuses and relays after reconnecting battery, all check out good. Tried to start it.... nothing.

Jumped the CEL terminal and it flashes 11 times. There are only 13 codes for the 85. Checked the list and 11 reads as follows:

Short circuit in Check Connector T with A/C switch ON or TPS - IDL point OFF
- Defective A/C switch
- Defective TPS circuit
- Defective TPS
- Defective ECU

I bought a used ECU a few weeks ago thinking it might be the ECU. I tried both ECU's after everything was put back together. Maybe they're both bad? I could test the TPS circuit and/or replace the TPS (only component I didn't replace). Anyhow, the project comes to a halt for now. I'm tired of messing with it so it'll sit until someone else works on it. Thanks for all the input and suggestions on this thread.

zerokelvin

Just for my own clarity, I used the stethoscope again while cranking. NOW I can hear the injectors clicking. Also listened to the COR and the Fuel Pump and they are working while cranking. Rechecked spark, spark is good on all four. I have a confirmed working AFM... so what gives? Air, Fuel, Spark, Compression..... should start and run..... Bad ECU? Of the 13 possible CEL codes you can get from this truck, every single one of them has "faulty ECU" as one of the possible reasons for the code.... if the ECU is bad, will it not even start, let alone run? Maybe bad fuel? I just siphoned all the gas out of the tank and heading off to get fresh fuel. After I did the rebuild, do I have to do anything special to the new fuel filter? Like run fuel through it before I put it on, etc? I'm missing something... this engine should be running and it's not. Really aggravating.

RAD4Runner

That's frustrating for us as well.
I'm sure you'll get fuel from CSI while cranking even if ECU were bad, but don't know about spark.