Aloha

On a quest to solve my hard start issue I am baffled at how my truck still starts and runs* and idles flawlessly (as of today). My 22RE has a difficult time starting when the engine is cold and is south of 2/3 full of gas. The starter works, the fuel pump works (I can hear the hum when +B and FP are jumped) and I believe the CSI and the switch works because she fires right up (cold) when the tank is full. I'll check that next though. So search results are pointing to a faulty COR. I admit I'm not the best at diagnosing electrical issues (but getting better) but with the help of this blessed forum and 4Crawler's site, I gave it a go.


I'm not hearing or feeling the COR click when the starter is disconnected and I put the key in start & when the +B and FP is jumped. There's 12.6V at the +B socket (of the COR) so I know there's power going in. I did the tests on the relay: STA & E1 pins -passed, +B & Fc - passed. I didn't understand the Fp & +B tests (..I put the ohmmeter to them and didn't get a change in reading.) What does the Infinite/Open circuit mean when the relay is OFF? and 0/short circuit when the relay is ON?
I want to know this because this may be a critical test when I'm in the junkyard pulling COR's. I know that more tests need to be made on the COR with power and with a load but the thing not clicking is a sure sign (right?).

Please correct me if I'm wrong but I'm thinking the fuel pump isn't being turned on by the COR but somehow there's enough fuel (& magic) to start when the tank is full/almost full. So for now I have my trusty paperclip to get her going but I know that it's a safety issue as I love my truck but don't want to go down in flames with her.

Any insight will be truly appreciated.
Mahalo in advance!

 

JUMPING Fp to B+ merely bypasses the COR contact it will not make COR energize.
DO NOT ohm-out B+ to Fp when relay is plugged in; you might damage your multi-meter.

How did you test STA & E1 pins -passed, +B & Fc?
With relay plugged in, did you get 12V at STA when you put IGN in start position?

 

I'm sure he's testing just the relay with it out of the socket. These two tests are for continuity in the coil. B+ to Fp confirms that the contacts aren't welded closed. Unless you jumper 12v to one of the two coils, you won't be able to test those contacts with the relay actuated. But that is almost certainly not the problem. You have a fuel injected truck, and it WON'T run without the fuel rail pressurized by the pump.

I assume that whenever it's hard to start cold, using the paperclip FP-B+ starts it right up. So your diagnostics are in the right direction. Since the starter will turn with the key to Start, your problem is probably not in the ignition switch. Since it will keep running (no jumper) once started, your problem is probably not in the VAF or the B+-Fc coil in the COR. What could be happening is an open in the STA circuit to the COR, so that the STA signal isn't closing the relay. Instead, as you crank, the engine pulls enough air to just barely get the COR closed long enough to start. Once it starts the Fc closes and the COR stays closed, keeping the fuel pump running. But when it's cold, this intermittent closing of the COR (via the Fc in the VAF) isn't enough, and it's a hard start.

What does this mean? It means the Rad4Runner is right on the money (again). With the COR out of the socket, check for 12v to ground on STA (socket) with key to Start. If that's missing, it's probably a wiring problem between the ignition switch and the COR socket.

Or ... you could have a shorted Fc coil in the COR, I suppose. It will pass the continuity test you performed, but not pull in the contacts. So just apply 12v to STA-E1 (on the relay, out of socket) to confirm that the relay clicks (do it separately to Fc-B+ as a sanity check). To be thorough, hook your ohmmeter to B+-Fp when you click the relay; the resistance should go from infinite to zero. As Rad4Runner reminds us, be careful to not put any voltage on your ohmmeter leads. It could damage the meter, and if not that will blow the fuse in the meter.

I don't think it's your COR, but the above test is worth doing. If it fails that test (and only then), RockAuto has CORs for as little as $25. Buying a 25-year old salvaged COR is probably false economy at that price.

 

Thanks for the replies gents.

I will dutifully perform these tests in a couple days and tinker a little bit more and report back. I have to stay immobile..doctor's orders. In the meantime, here's a picture of the ol' Black Pearl during last year's eruption:

 

Can't sit still for long so..

The results: 9.4V to the STA (socket) with key to Start which I'm guessing is NOT enough to make the COR close that powers the FP. At first I disconnected the starter wire and nothing so I activated (or is it de-activated?) the kill switch that interrupts the ignitor so it cranks but won't start and I got that result. So I have a wiring problem between ignition switch and the COR..you guys are good! I could only find this schematic:


It's low-res and the ignition gets cropped out but I can see how they are connected. Are the worn out contacts of the Ignition switch (part of) the problem? I did the MOD that puts power directly to the starter because of that dreaded intermittent no start issue a few years back and it has served me well so I'm guessing there's voltage loss from the Ignition switch to the COR?

So, instead of messing with the Ignition switch can I do the same kind of thing where I go from the starter directly to the STA pin on the COR? I want to hear that click, dammit!
Funny thing, I distinctly remember my GF's '93 making these sounds when you would turn the key to RUN and it was odd to me that mine's one didn't do that..I can barely hear the FP going

Again, thank you for these electrical insights

 

I think that switch is still available as a new old stock part, baring that I'd think about disassembling it and cleaning up the contacts, a final step would be adding another relay but I'd wire it into the STA at the column since it also goes to the coldstart system.

 

I put 12v to the relay, STA-E1 then Fc-B+ and sure enough it clicked but when I carefully put the ohmmeter to it, I got 0.4 & 0 (eventually) respectively. Is that 0.4 ok?
Also, I have a parts truck and I was thinking of pulling the ignition switch out of that. I can hear your head shaking, Scope103 but you know, we have these trucks cause we're cheapskates and may as well try em, right?


Does this test have to be done with the switch detached from the socket but connected to power?

 

Your ohmmeter isn't very accurate at that low a resistance (to measure that few ohms you would need, among other things, a 4-wire Kelvin connection). So I don't think 0.4 is "real."

If you really suspected the COR, you could hook up a load that pulls at least one amp (like a headlight bulb), then measure the voltage drop across the relay terminals. (The voltage drop is what you really care about, after all.) If you can accurately measure the current you can use ohm's law to compute the resistance, but you don't really care. If you have a drop of more than 2 volts to a light bulb, the relay is probably not good enough. But I don't think that is your problem.

The FSM measurements on the ignition switch are continuity, so they are measured with the switch disconnected from the socket, and with no power.

 

UPDATE:

I got another (30 yr old) switch from my parts truck, all the continuity tests passed but it tested at 8.7V (the other one was 8.4V) at the STA terminal on the COR (socket) and presumably not enough to make it work. I did an extensive search on other sites and found that it all ties together to that intermittent no start/click only that afflicts our vehicles. The erroneous factory wiring that has plagued us classic import enthusiasts for years seems to be the culprit. Hopefully the new ignition switch I ordered from Rock Auto will do the trick along with my existing starter relay reroute straight to the battery.

Will report back after switch switch

 

UPDATE: SUCCESS!?

I installed the new ignition switch today and other than the failed first try, she started perfectly 4/4 times. FYI I used this part:




I was happily surprised that the part was made in Poland. RAD4Runner posted that he first went with the Beck/Arnley switch but it fell apart upon opening. This one looked solid..hopefully it fixed the problem.

 

I didn't see that post by Ray but considering its a spring loaded rees switch I would expect to not be able to find all the parts after removing the cover without extreme caution.

 

The switch is assembled by snapping the white cover on. If clips are too loose or assembly equipment pressure is not in control, cover may not engage completely. That's probably what happened with the Beck-Arnley IG switch I got.

 

hey RAD, did that Ignition Switch get your rig to go vroom every time? Today, sadly, I still have a hard start issue though it IS better than what was. It'll take two cranks before she fires up but at least she fires up (eventually)..so the new switch did something. I haven't had time to zero in on where the problem is but will continue to diagnose. I think it's worthwhile to keep looking into this as I'm sure I'm not the first or last to have these issues.

To be continued..

 

use more definitive language to describe symptoms. if it was “cranking two times” before firing, the switch isn’t the problem, because the starter is engaging the flywheel and spinning the crankshaft.

 

ok let me try again:
I turn the key, the starter will crank for about 4-5 seconds without firing, I stop and yell obscenities (not at the truck but at my efforts). I turn the key again and it maybe eventually starts. My thought was that the erred factory wiring that has possibly corroded or pitted the contacts of the ignition switch over the years has compromised the rest of the (STA) circuit that leads to the COR and switches on the fuel pump. I will diagnose some more today when I get a chance.

 

the contacts in the switch might be pitted, but because the starter engages and operates, the ignition switch was not the cause of your most recent non-start. in fact, your starting circuit was working properly. you may have a fuel delivery problem, a timing problem, an injector issue, or other problem. you’ll need to continue to test components/systems to correctly diagnose the problem.

 

Reason I replaced my ignition switch was different; It was getting stuck closed that starter would not stop cranking.

Need more obscenities. I have a few more in different language I can share - LOL!

ON the 22R-E the CSI gets power from the contacts of the now (I assume) correctly -wired starter relay (see below), so the ignition switch does not affect it anymore.
The critical resistance measurement for the CSI timer switch is fro STJ to the brass body of the switch. Then engine is cold Resistance from STJ to Body (ground) should go low. This will connect negative side of CSI to ground and inject fuel. However, Toyota does not have spec for that - DUH!

BlackPearl
I suggest you clean all your temp senders, their connectors, their mounting threads AND THE THREADS WHERE THEY MOUNT ON THE ENGINE to bare, shiny metal. Those that only have one wire to the sender rely on contact with metal block for grounding. That has to be done every 30 years or so -

 

Quote:

BlackPearl

That was the first thing I did as suggested by the FSM and Yotatech. It didn't change a thing and resulted in me posting and asking y'alls for help in the first place..

I just did this test and the STA-STJ resistance was 80 with an outside temp of 73F so that seems ok. I couldn't see into the thing so I'm assuming that I put the + of the ohmmeter onto the STA and when I tested to Ground it was reading 160 so does that mean that my switch is no good? Also, does this even matter? During the day, the temp only ranges from 75-80F so is the CSI even a factor when the engine is "cold"?

Then for fun, I tried starting and she fired right up

 

UPDATE:
The truck starts on the first or second try these days which is fantastic! As wally suggested I try and look at the other components that make a truck go vroom. One day I was checking out my kill switch that interrupts the 12v going to the injector/coil and the connection just popped off. So I reconnected that and I realized that the insulation for those wires is also the ground?
Does anyone have the wiring diagram for that?
That was working for a while until it didn’t at which point I did the tried and true method of just throwing parts at it (lol). I got lucky I think because I put a new injector coil (looks like a beer can) and that’s where I’m at today.
she starts for the most part so the next step is to check the timing.

 

Kill switch? Toyota didn't install it, so you're unlikely to find a wiring diagram here (or anywhere else). "Insulation" can't be a ground; it doesn't conduct electricity. There are 2-3 shielded wires in your truck (knock sensor, radio antenna, ) but I don't think you'd mistake braided metal wire for "insulation."

The injectors all have small coils internally (about the size of a 5 quarters), but they aren't replaceable. The ignition coil in older trucks is "about" the size/shape of a beer can. (The easiest way to connect a "kill" switch is to interrupt the power to the igntion coil.)

if the wiring to your kill switch "just pops off," that will definitely cause your problem. I'd look at that (heck, just rip it all out!) before messing with any ignition components.