I tested the hall effect voltage and found it at 8.8v It should be 1volt less than battery. The battery is 12volt, I tested it. I followed the wire back to the smec, it is still 8.8 where it leaves the computer. The computer has been tested with a new one and also replaced with a new one. Bad voltage to the computer or maybe a bad ground???

 

according to my Haynes manual there should be approximately 8 volts with the engine off

 

Wolfie is correct on the 8 volt power supply to the hall effect. Are you still (after 2 years) experiencing the same problem? If so remove the air cleaner and look down into the throttle body to check the spray pattern of the injectors. There should be a fine solid cone of fuel with no gaps or streams that each reach the sides of the throat. I have seen even new injectors that don't spray properly.

 

In regards to the gear spinning noise, I could be wrong but it sure sounds like the fuel shutoff relay. You said it makes this sound when you turn off the motor? Mine's pretty noisy and threw me for a loop when I first heard it.

I just changed my idle speed control (ISC) actuator and it completely helped drivability. The truck felt like it would putt-putt to get up to speed and forget hills. I too was running down the list of sensors and when I rebuilt the throttle body, the inside of this idle speed control was completely nasty and when I adjusted the screw it made no difference. It was pricey and most places wanted a $100 more or less but Pepboys came through for $30 cheaper @ $69.99. I just figured that this piece had actual moving parts instead of just being a sensor.

 

BTW, I hope your feeling better soon SEAL. Take a little time to enjoy a cup of joe and relax a bit. I hope you rolled a little 4 wheeler and not a 4 wheeler truck.

 

I hooked up a tach and it will idle normal and then quickly drop and then return to normal, this happens every few seconds. When the engine is cold the idle control motor is constantly changing like it is seeking. When I raise the RPM slightly above idle the engine surges up and down. This why I was thinking the hall effect?

 

brucris: Have you checked the injector spray patterns?

SixGun; I hate to dash your hopes but it was a Polaris 700. 650 lbs with an additional 200 lbs of tools and equipment strapped to it because I was headed down the mountain to work on my JD 450 crawler/loader. I would have been better off if it had been a 4 wheeler truck because they have roll cages. But thanks anyway for the good wishes.

 

The spray pattern looks OK, I can't see as well as before. I am going to have my son take a look on Saturday. A friend said to hook up a timing light and shine it in the throttle body to get a better look. Do you think that will work? Yesterday, the RPM's were all over the place. The idle goes up and then down and then up again, it would not maintain a constant RPM for even a second. The idle control was not moving as this went on.

 

It is best to check the spray pattern in as little ambient light as possible and I use a flash light. The light shining on the cone shows it best. I have never used a timing light for it but I would think it would give a good light source. What RPM range is it actually idling in and what is the timing set at? If the RPMs are too low the ISC actuator may not be working or the MAP sensor may be giving the computer bad data. Are there any strange noises coming from the front of the engine? You said it hasn't run right in 5 years. Has it been this bad the whole time or is this new and for how long now? If it is a new problem what symptoms was it having before that weren't right?

Just a note about the gear spinning noise when you shut it off. It is/was probably the ISC motor resetting.

 

I checked the timing and it was off a little, I set it correctly. The timing mark on the crank moves constantly when the light is on it. I set it as close as possible. I would think this isn't normal??? Either my new tach is bad or somethings going on, I'm getting zero when it is idling but it jumps up to about 800 once in a while. I'm going to borrow another one saturday. Years ago the engine would be running fine and then it would die,after a few minutes it would start and run good. Other times it would lose power, couldn't even go up a slight incline, then out of the blue it would be fine. It started running rich but a fuel reg replacement solved that. I know that new doesn't mean its good but here are the parts that have been replaced, mostly by shops and dealer. egr,map,ips,coolant temp,Isc,oxygen sensor/3 times,cap/rotor/wires/plugs, I'm not sure about the hall effect,injectors,coil, fuel pump.
When I drive it, it has all its power most of the time. when it gets to normal running temp it idles poorly and the oil light comes on and the oil pressure gauge reads just below the safe range.If I give it a slight amount of gas, the light goes out and the pressure goes up to normal. Saturday I will check the spray pattern.