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Ok deal I will add that to the list.....Then drive this truck off a cliff soon after if I still can not figure it out. Pics to come of truck wires to each sensor and of it on fire at the bottom of a canyon.....
ok I will pull the CSI with everything plugged in and check for a leak. Would hot or cold make a difference? If no leak then next step would be coolant temp sensor to ECU next to time switch?
go over everything make sure it's plugged in and routed like it was from the factory (you know like that injector that wasn't plugged in you've neglected to mention for who knows how long)
Remember to post those little details, were not there.
See if it runs, if it don't run do clear flood, if it still doesn't run check for spark.
Ok deal I will add that to the list.....Then drive this truck off a cliff soon after if I still can not figure it out. Pics to come of truck wires to each sensor and of it on fire at the bottom of a canyon.....
go over everything make sure it's plugged in and routed like it was from the factory (you know like that injector that wasn't plugged in you've neglected to mention for who knows how long).
This was only for one test weeks ago. It has been plugged in this whole time. trust me I got that much down.
Got the new voltage checks.
also found that the wire I plugged into the sensor turns the vsv on and off if plugged in so I am leaving that wire off now. Still trying to find where it goes on the ecu. I have a small fuel leak from the bottom of the fuel pressure dampener. Screw is stripped out. Also here is the image of the aftermarket coolant reader.
Forgot to mention this was the battery voltage before checking ecu. Also tested cold start injector(not leaking)
Last edited by YotaRick27; 02-22-2018 at 06:33 PM.
Got the new voltage checks.
also found that the wire I plugged into the sensor turns the vsv on and off if plugged in so I am leaving that wire off now. Still trying to find where it goes on the ecu. I have a small fuel leak from the bottom of the fuel pressure dampener. Screw is stripped out. Also here is the image of the aftermarket coolant reader.
..battery voltage 12.61 at the posts..
..pulse damper..
..thermo couple temp..
Forgot to mention this was the battery voltage before checking ecu. Also tested cold start injector(not leaking)
Ok the pulse damper isn't adjustable, the screw is there as a reference to check for fuel pressure (with fuel.pressure in the fuel rail the screw lifts off the damper body) these are like 80-100$/iirc.
Clarify those voltage checks looks like
#1@9.2
#2@12.3
You have massive voltage drops somewhere.
Need to find these. Start on the ground side. Battery negative post to negative battery cable end, we want zero or less than 0.3. Repeat battery negative post to exposed battery wire, same goal zero or less than 0.3. Repeat battery negative post to inner fender (scratch through the paint to get a clean spot). And finally battery negative post to engine block.
Probably faster to just clean and tighten all those, but then you won't know for certain where or what the issue was.
With good clean grounds we start on the positive side. Battery positive post to end of fusible link wire (yes we skipped over a couple junctions, to speed things up, if you get a voltage over zero to 0.1 work towards the battery post)
Now with clean grounds and clean power to the distribution block. We want to check fuse voltages. We should be able to use any clean bit of metal for ground now, always double check the ground by taking the positive lead to the battery post and you expect to see the same as if you had the negative probe on the battery.
Take readings with the fuse in place, there is a bit of exposed metal on each side of the face on a blade style fuse. Test EFI, Engine, and IGN (sorry for the shotgun scatter here if I taskswap the browser is going to eat my post and its getting long), hopefully one of these is partially blown or loose because that is a simple fix.
Test voltage at the efi relay (relay removed), we know the relay is dropping some voltage already (0.03ohm at rest iirc, without knowing the current draw I can not calculate the drop), to get the actual voltage dropped here the fuse box has to come off its mount and I don't remember how accessible the back side is. (You could put extension wires, but I'm not sure the size spades).
So here is the problem in a nut shell. When you crank the voltage at the battery drops about two volts. You are only starting with about nine to the computer which is enough to run the five volt regulators inside the computer but not the nine.
The voltage checks at the ECU, #1 & #2 should be much closer.
Holy crap! It’s running great and has 13v at ECU picked up new cables and went through every ground and cleaned it. It works now praise the lord!
Got a free light at harbor freight Nasty old ground cables Fuel was leaking into this ground through the bottom of the dampener Wet Wire brushed and painted over the rust Cut and soldered in new ends Not happy on this guy I hate when people do a quick fix Polished all the bolts High heat in this area..... hint hint Carefully got the old wire out without breaking this piece Polished and soldered Power steering ground polished it too New voltage!!!!!
I'm going to be perfectly honest Rick. I've tried to keep up with this thread, but I keep getting lost. I'm an ME, and electronics are far from my thing. But, if you're excited, I'm excited for you. I wish I could offer more help, but I've been drowning myself.
CO 94 PU is a life saver, isn't he?
Anyway... that ground from the Neg battery terminal to the block. Is that something you added, or is that a factory ground. Cause... I don't have one there. (asking for my own purposes)
Anyway... that ground from the Neg battery terminal to the block. Is that something you added, or is that a factory ground. Cause... I don't have one there. (asking for my own purposes)
Congrats.
Thanks. From the negative terminal on the battery I have one wire to the inner fender and one wire to the side of the block. Then there is a ground wire on the driver side fender that goes to the power steering bracket and lastly a ground wire on the back of the motor to the cab. Then the efi harness ground. That’s all I have.
Rick, you reused that fusible link wire to the distribution box (the one you soldered)? You'll want to pick up a new one from the dealer, its a big safety thing if you changed that to a "standard" wire, and a only having the small backup crimp may give you issues later plus they are cheap.
I dig the fox & hound wire tracers, always thought those were cool.
The FL was probably your bigger issue, heats up during cranking which is why the CSI wasn't firing steady (shown in the video). The block ground wasn't to bad but the chassis ground was definitely crap, and the crimp to the battery lug was questionable.
Your hot start issue may still be there, keep the multimeter and fuel pressure gauge handy for awhile.
Jnky, you might have a different layout of ground straps, check for one from head/block to the firewall. You can always add one from battery to block for piece of mind.
XJnky, you might have a different layout of ground straps, check for one from head/block to the firewall. You can always add one from battery to block for piece of mind.
Working from home today so I actually went out and looked, and tucked up behind my heater hoses is a ring terminal bolted to the firewall and a short section of broken black wire going to it. So, that's an easy fix.
Forgot to check the battery ground to block. I suspect I have one, just not seeing it easily. Because if I didn't... I wouldn't have had any grounds before I found the missing harness ground.
Working from home today so I actually went out and looked, and tucked up behind my heater hoses is a ring terminal bolted to the firewall and a short section of broken black wire going to it. So, that's an easy fix.
Forgot to check the battery ground to block. I suspect I have one, just not seeing it easily. Because if I didn't... I wouldn't have had any grounds before I found the missing harness ground.
nah you did, the ECU case is grounded iirc but it doesn't have really thick traces on the board. On the alternator loom.there is a ground wire also.
There you go, Rick!! Bare, shiny metal!
I suspected those tired looking connections, too. Good job,Co_94_PU, for insisting that Rick check his voltage drops.
Second getting a brand-new F.L wire.
XJNKY, Yeah, the battery negative to block ground is how the starter motor and solenoid get their ground, especially the starter motor. Another member here with the first-gen truck says his truck does not have the engine block ground. (It might have been another oversight on Toyota's part.)
Last edited by RAD4Runner; 02-23-2018 at 07:42 PM.
XJNKY, Yeah, the battery negative to block ground is how the starter motor and solenoid get their ground, especially the starter motor. Another member here with the first-gen truck says his truck does not have the engine block ground. (It might have been another oversight on Toyota's part.)
Ray, I'm not sure why some of them come with the alternate ground strategy, big cable to fender and big cable to rear of engine from firewall, but apparently some do and they seem to be OEM. We can only speculate these are done by a Chevy mechanic, quite possibly initial production from the CA plant. Also maybe credited to the difference between early "EFI" or "tccs", you will find these references in early Toyota tech documents. From an engineering perspective having multiple ground paths is considered a bad idea, from what I recall you get an rfi leak, so you wouldn't/shouldn't have a ground loop (battery to block, bock to firewall and battery to fenderwell).
And cudos for Rick for not pushing it over the ridge into the gulley. I can only lament that he didn't show the voltage drops on those connections before he altered them. While I know, and understand, he was under the gun to get it up and running before his loaner was reclaimed. It would have been a good demonstration if why testing can show where the problem is and prevent people from " throwing parts " at a problem.
Rick. I would love to come up for that event, but very worried I would have to trailer my 4runner home because my turbo grenades, and I can't afford that expense. Keep us posted on your build thread if the hard/no start reoccurs and we can revive this thread or start a new one.
... We can only speculate these are done by a Chevy mechanic, quite possibly initial production from the CA plant... .
My 1986 was made in Japan. I wonder how much later Toyota started having them made in the U.S. however, I read somewhere that rear seats, etc. were added after they were delivered here in the U.S. so they shipped as trucks for lower taxes. I do see hints of after-market quality on the rear seats, hinges and rear deck parts.
... From an engineering perspective having multiple ground paths is considered a bad idea... ...so you shouldn't have a ground loop (battery to block, bock to firewall and battery to fenderwell)....
Correct. Ideally all grounds should come from a single point. It may not be entirely possible, but we can get close to ideal if "main" ground points where connected to a common point, i.e.,:
1) Battery neg to inner fender- good on stock.
2) Battery neg to engine block - good on stock
3) Battery neg to firewall near rear of engine block, instead of to engine block on stock.
02-22-2018, 08:29 AM
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