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The Spill control Valve Mystery

Beau

Well-Known Member
Joined
Jan 28, 2011
Messages
2,014
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guyana
So if you've been following my separate thread, you'll know my cruiser overheated and then it wouldn't start back. Traced the problem down to the spill control valve (Again). I have one on the way but just out of boredom and my understanding of things I thought why not see if I can fix it...

I've tested the valve at home and it's reading 2.2ohms, just outside the regular 1-2ohm reading. I'm thinking when she overheated the coils inside the valve must have burned up or the coil sheeting deteriorated? However, I've also tested the valve directly with 12 Volts, for a millisecond multiple times and it clicks. However I assume it's working like this because it has the available draw off the battery compared to the wires it connects to.

It's my understanding that higher resistance (ohms), less volts gets pulled meaning there is a lack of power for the solenoid to work, correct? If this is true, Can I use a resistor in order to reduce the ohms of the overall circuit within the 1-2ohm range and test it? Will this work? From research, adding a resistor in a parallel circuit reduces the resistance unlike when you run it in series, right?

Any electricians out there who can help me out and confirm my thinking.... :think: I don't want to jump the gun and do it yet, as the negative terminal on the circuit runs back to the ECU and so I don't want to fry anything before knowing it's safe and plausible.

I've also oppened up the valve and cleaned everything up so the plunger and pieces inside are working smoothly. This time I took pics for you all, will upload them soon!

P.S - If anyone has a 1KZT Mechanical Injection Pump laying around, send me a PM! :whistle:
 
Hi Beau, I'm a sparkle and this sort of thing is my bag. I would be very surprised if your 0.2 ohms was anything to worry about. If anything it's going to draw less current from your ECU at that but it is more likely connection resistance. I would also be very surprised if your stripping and cleaning made any appreciable difference as the micron levels of cleanliness are going to be difficult to achieve. Could it be that some dirt got in there before?

Anyway, putting a resistor across the coil will not help unless the ECU is looking for that specific reading. If you can make it work, try applying volts for a short time while monitoring temperature. Once it is warm, see if it still operates. I have had (other) coils go thermostatic before, one minute they work the next not, due to a slight break. If you had cooked your coil, I would expect the resistance to have lowered, increased to very high (or open circuit), or been a dead short. I wouldn't worry about the reading.

Is this a Denso common rail pump? If so I believe there are two different coloured valves and both of them give trouble I am told. One is the PCV Pressure control valve. There's plenty of info on the net if you google Denso PCV. Apologies if this isn't what you are asking BTW.

Regards

Richard
 
Having another read, the resistance will be what governs the current drawn, not the voltage applied, however if a higher voltage is applied then more current will be drawn. Ohms law in action! [emoji6]
 
As far as i'm concerned your the forums expert on these pumps Beau which begs the question - how many times have you rebuilt yours ?

Pump failure doesn't seem to be a common issue so maybe you should give some thought to why yours fails when others don't , check the wires running to it for chaffing and that sort of thing , of course it could just be that you have owned your truck longer than most but i thought it worth a mention as we tend to stop looking for alternatives when we become familiar with a problem .
 
Having another read, the resistance will be what governs the current drawn, not the voltage applied, however if a higher voltage is applied then more current will be drawn. Ohms law in action! [emoji6]

Yes, this was my thought too. So with the resistance now reading 2.2ohms, the current draw is under the amount required to trigger the solenoid? This is why when I connect the solenoid straight to a 12v battery source I get a click.

The spec says it should be between 1-2ohms, ideally 1.4ohms. If outside replace. That's what it says. I've checked power going to the valve, and it's as it should be. On crank it peaks around 12v, on ignition theres a slight 5v there. All of this right, from what others have said as well. It's a Denso pump for the 1KZT-E engine. And the spill control valve is also similar 99% to the 2.4 engine as well. This is the valve at the back of the pump that regulated fuel to the injections but also works in stopping and starting the engine...

And if there was a break in the coils, would this not increase resistance in the coil? Normally a larger wire has less resistance as there is more mass for the current to pass through, and so the opposite applies? I also thought with there is a relationship between heat and resistance, higher resistance has at higher temps, so wouldn't this increase the resistance even more out of the range? I thought about the idea of sticking it in the freezer for a bit and testing it :icon-rolleyes:
 
As far as i'm concerned your the forums expert on these pumps Beau which begs the question - how many times have you rebuilt yours ?

Pump failure doesn't seem to be a common issue so maybe you should give some thought to why yours fails when others don't , check the wires running to it for chaffing and that sort of thing , of course it could just be that you have owned your truck longer than most but i thought it worth a mention as we tend to stop looking for alternatives when we become familiar with a problem .

I do know a fair bit but I'm forever learning. However the electrical part it what puzzles me.... I've had my Spill control valve in and out over 10 times on my truck! Had it apart over 6 times. It's like clock work to me now haha

Last time my valve failed it was down to filters being blocked up (Bad Diesel source :icon-rolleyes:), as well as crud being in the valve itself. After rebuilding it, it was fine for a few more years until yesterday. I imagine having the car sat not running for a good 9 months may have made it a little stuck.... The average person that suffers from the spill control valve problem just replace the pump when really it could be something as simple as a blocked filter.
 
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Yes, this was my thought too. So with the resistance now reading 2.2ohms, the current draw is under the amount required to trigger the solenoid? This is why when I connect the solenoid straight to a 12v battery source I get a click.

The spec says it should be between 1-2ohms, ideally 1.4ohms. If outside replace. That's what it says.

Then I think you may have answered your own question here Beau. It needs replacing according to the manual as its out of spec.

Going back to the resistor across the coil idea, this won't help the coil, only show the ECU the correct circuit resistance. The current will be shared between the resistor and the valve coil proportional to the resistances. If your coil is kaput as per the manual, it's kaput and no amount of cleaning or other time will resurrect it with any semblance of reliability.
If this is the valve you've had in and out for so many times and it works after each time, maybe a new one will sort the problem for a longer time?

I cannot think that an overheated engine could have affected the valve (unless it's really close to the overheated bits). I'm not saying it's impossible, I just cannot see it happening. Now wiring as Shayne has said could possibly have been affected by heat if indeed it was that close to the overheated parts of the engine.
 
Then I think you may have answered your own question here Beau. It needs replacing according to the manual as its out of spec.

Going back to the resistor across the coil idea, this won't help the coil, only show the ECU the correct circuit resistance. The current will be shared between the resistor and the valve coil proportional to the resistances. If your coil is kaput as per the manual, it's kaput and no amount of cleaning or other time will resurrect it with any semblance of reliability.
If this is the valve you've had in and out for so many times and it works after each time, maybe a new one will sort the problem for a longer time?

I cannot think that an overheated engine could have affected the valve (unless it's really close to the overheated bits). I'm not saying it's impossible, I just cannot see it happening. Now wiring as Shayne has said could possibly have been affected by heat if indeed it was that close to the overheated parts of the engine.

Yeah, I think so too, I'm just kinda messing around with it at the moment, waiting for the new one to arrive. I've had it in and out when I had fuel blockages somewhere and I was trying to locate it, however it wasn't the valve that was the problem. Being it's 17 years old with 190,000 miles it was bound to go and it's just my theory that maybe the heat pushed it over the edge. I can't see it happening either, but the fact it went totally kaput after overheating made me think so... Thanks anyway, I appreciate your help with regards to the electrics!
 
Good point and the fact it died at the same time is likely to be significant. I expect you have already, but do check for wiring damage. As you say, the ECU (likely) earths the valve to operate it so if a wire had got damaged and earthed it would run the valve, possibly at a higher voltage than it was designed for long term (12/2 = 6A!!! Really high for a valve coil) hence the damage (though as in last post I wouldn't expect a slight raising of the resistance to be the outcome).

Good luck with it, I'm certain the new valve will have a positive effect.
 
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