Testing Enjectors

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Mar 13, 2003
North Front Range, CO
I it worth the time to have the enjectors tested? Has anyone done this either them selve or had them tested at a shop?
The answer to your question depends on several things. First and most important, you have to tell us some things about your truck and if you are having any problems. It's a bit much for you to think we are going to remember your model, mileage, accessories, etc. (yes, I know your model year is in your sig line.)

Most people will recommend having the injectors balanced before major engine upgrades like the blower or a turbocharger.

You haven't given us enough information to make an intelligent recommendation.
A footnote:

The pesky things are a riot to get out, and the wiring to them, on a vehicle with lots of miles and a gillion heat cycles, is very fragile. If the harness is moved around too much, you may end up needing a new($$$$$$$$$$) one.

I wouldn't touch them unless you have a valid reason to do it.

Engine wiring part # 82121-60343 approx $350.00.
Look at all those f*!#(%# connections. Been there - doing that.
I was just woundering if they are prone to need service or not? And if any one tried it and what they got for results?
I will have the intake chamber off cleaning up the EGR and intake chamber. I ordered the parts to replace the enj. non-reusableparts when they are off. I have 219k mi and have lots of power no problems, except for code 71 EGR that comes and goes. It is not using any Mobil 1. I thought I would replace the insulator,grommet and o-ring while in there but I don't want to cause more problems if the wires are going to get fried. While there I will check valves,replace the spark plug tube gasket (one is leaking).
Should I retorque the head bolts? Dealer said I should.
While I have everything opened up what else if any thing should I check.
kurt 94 fzj80 runs great.
I have tested nozzles on diesel heavy equipment. Basically the idea is to look for a nice even spray pattern. No dripping. If it only drips it is no good. On a diesel it was very easy. Just pull the nozzle, hook it back up to the fuel line, turn the motor over, and watch the spray pattern. I used to take them to the equipment dealer and all they would do is hook them up to a hand pump and do the same thing. The gas cruisers are fired electrically so you just need to rig up a fuel line and a couple of wires, fire them and watch the pattern. Usually it is a good idea not to make sparks. :slap: I imagine you have the Toyota manual since you are thinking about retorqueing the head and would need the torque sequence. In the manual it goes through the whole proceedure of testing resistance and checking volume but from my experience just see that it has that nice fine mist pattern. Injectors do go bad. It usually results in a rough running engine. Toyota injectors are protected first by the fuel filter and then by individual filters. There is no set time or distance that I know of that they should be checked. Your vehicle could be brand new and you get a load of crap for gas and could have problems. As Dan said though, sometimes you open a can of worms but hey, if things get that bad you can always go fishing.
If the wires are brittle to enjectors, wouldn't they brake in heavy off roading? Or don't they have much room to move? If they are brittle, I might as well replace them. How hard is it to replace the wiring?
When you examine the plugs, look for a lean condition which could be a bad injector.

See: http://www.gnttype.org/techarea/engine/plugs.html

Let us know if you plan to have them balanced. The place that Robbie recommends is around here somewhere. You will have to send them off and wait.

>> While I have everything opened up what else if any thing should I check. <<

Since you are reporting an EGR code, checking (or replacing) the VSV for EGR would be good. It's hard to get to with the intake on; easy with it removed. There are a few tests in the FSM; mine was bad and failed the resistance test across the 2 terminals.

Is it going to be a good time to replace the heater hose under there? Will it be easier to get to with the intake assembly off?
My wires were brittle by the EGR valve. Number one cylinder just started to dump fuel resulting in some embarrassing blue smoke and a bad miss. I understand it happens moreso with a supercharger. A tech told me if even one strand of wire gets broken this problem can happen. Look at the picture I posted and see all the connectors. The harness runs from the computer, through the firewall, and all over the engine. I haven't installed it yet so can't tell you how long it will take but it will require some careful connector marking and routing to get it in and working.
absolutely, do the hose. I would use a silicone one and lined clamps. face the clamp drives downward so that you can get to them from below in the future.

>> Should I retorque the head bolts? Dealer said I should. <<

I asked this question of the 80sCool list a few months back. The context was whether or not this would be a preventative procedure to lessen the chance of a head gasket failure (my favorite obsession). The responses back were that it wouldn't hurt but it also probably wouldn't help. Nobody had tried it so there wasn't any data to support it one way or the other.

It wasn't clear to me if the head could be retorqued without removing the cams. If it can, then I would say go ahead and do it. If it cannot, then don't. BTW, please let me know if the head *can* be retorqued without removing the cams.

I got a silicone lined hose from John Deere. It is a high temp hose that can take the heat of a turbo. They had a hose that was super high temp and would out last the 80 ten times over, but there is no way to clamp it down as it is so thick. The Deere parts guy gave me the hose at no charge :D.

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