I purchased one of these recently:



AC/DC Digital Multimeter

It has a frequency function as well as the usual DVM features. My old Fluke 87 was almost unreadable.

 

How exactly do you test these sensors? what tools and wires on what sensors do i need to probe to find if they are working properly? Truck running, truck off, key on?

I assume a DVM but...

 

Well i got the truck to idle steady and not lope as bad. I cleaned my original iac but i think it was stuck because i put one from a different intake on it that came out of another truck that ran great and that helped it a lot.

I am still having trouble with the hard start. The timing is set at 9* BTC and will not tolerate any more timing than that with out detonation. It seems to fire up fine when sitting over night, but once it warms up it is hard to start...
How do i test these sensors with the DVM?

 

I use the values and info from here: Ford Fuel Injection

For most of the sensors I use the output signal values whenever possible. Back probe the wires with the Key On/Engine Off whenever possible.

The hard start/pinging issue is leading me to believe that the outer ring on your harmonic balancer may have slipped. Your timing settings may now be compromised.

 

Yea I'd tend to agree with rla2005, sounds like your wheel slipped. Easy way to tell, pull #1 plug, get it up on TDC on the compression stoke, verify you have it exact. See if the mark is a TDC on the wheel.

When you say The timing is set at 9* BTC and will not tolerate any more timing than that with out detonation. It seems to fire up fine when sitting over night, but once it warms up it is hard to start...

Hard to start as in cranks over hard, turns a few degrees then abruptly stops...turns stops...turns stops....turns stops? If so yea either your wheel spun on itself or a computer issue of some kind more likely your wheel spun some. Your timing is to far advanced even at 9deg on the wheel as set. Back it off a couple three deg from there and see if that helps it fire when warm but still has power on the road.

 

eveytime i back the timing off at all the truck runs like crap and stalls like crazy. ive put the piston at TDC everytime ive checked the timing to make sure that it was lined up correctly. it is set at 0* with the piston at TDC.

 

Do you mean the SIG RTN pin/wire?

 

You should always use Signal Return as your reference point. Put the negative lead of the meter on Signal Return. The positive lead on the meter should be used to verify the VREF voltage then also used to measure the signal output itself.

 

And you think i should be testing the ACT and ECT sensors for the values on FFI.com correct?

 

ACT, ECT, MAP and TPS to cover all the bases. You also need to figure out the root cause of the pinging when the timing is set at or below recommended settings. I think you have numerous items working against you right now. Those sensors are easy enough to check out. Once you have a handle on that, maybe the pinging problem will be resolved as well.

 

No... when it is warm, it will turn over like it should, but it will not fire right away. you have to push the gas down while turning it over to get it to start.

I know when my other plow truck was too far advanced the thing sounded like it had a dead battery when i tried to start it again when it was warm. This is not like that incident though... its just hard to fire when warm

 

Ok yea even that points them 4 sensors, one or more of them is off. The computer is not getting the correct information and it thinks the motor is cold when its hot / below sea level but is at sea level etc etc.

Testing them all you should narrow down the cause of the problem fairly quick/easy, be sure and test them when the motor is cold and then again once its fully up to running temp.

Did you replace the ACT and ECT sensors, stated you intended too back a few posts?

Reset, clear the computer after doing so?

 

I plan on installing them tomorrow. I have them just gotta get them in then i will disconnect the battery and let it sit over night and see how things play out. I will then surly test all of the stated sensors for the values at hot and cold temps.

I will post back to let you all know what i find.

 

I changed the ACT and the ECT with new ones and tested them. They both tested good hot and cold. I put the map sensor out of my other truck into this one and no change... I also swapped out the TPS witha known working one.

I'm at a loss with this one...

 

If you have speed density, you will have to have a stock motor(especially a stock cam), otherwise you will have to covert to MAF, which requires a later model computer, change wires around in the harness, and MAF sensor of course. Otherwise you are just wizzin' in the wind. Super tune, chips, etc, results are very limited for speed density systems, and if you have the E4OD transmission it makes it a little harder to convert, because the tranny is controlled by the computer.