question about VP timing and boxes

as i already said, you are trying to bandaid an issue. where did you get the injectors? were they pop tested?
 
Here is some old info I posted a couple years ago diagnosing the same thing, I ended up running just the TST and no timing during the winter, now this year with a 190 T-stat and a clean IAT I have very little shudder during the coldest days, goodluck.



IAT sensor - Ram Diesel Problems and repair



Yuup its the 24v timing shutter, happens on most 98.5s-02s with lots of fuel, I have dealt with this sense I did my Machs last winter, to get rid of it you need to put a warmer (190) t-stat in, and you need to fool the IAT sensor to think its warmer than it is, this can be done with a potentiometer, that way it can be set at stock voltage for cold weather starts, and then switched for hard driving, here is some more info


For those considering the IAT mod, here's some info from a previous thread describing what I did:
Quote:
First I verified timbo's suggestion by purchasing a 1k ohm resistor (1/2 watt for the thicker leads so it plugs into the connector) for less than a dollar and
bypassing the IAT sensor. The miss was gone, but cold starts were an embarrassing challenge. Recently I purchased an IAT extension harness and modified it to place a potentiometer & switch in parallel. The purpose of the extension harness was solely to avoid modifying the factory wiring harness. I placed the potentiometer and switch in series with each other, and the pair is wired in parallel with the stock IAT sensor. With the switch ON/closed the pot reduces the IAT resistance (tells the ECU the intake air is very hot so it pulls timing) and alleviates the miss. With the switch OFF/open it's the same as stock for cold starts. I didn't want to bypass the IAT altogether so the ECU will be able to verify that the intake grid heater is working. I also went with a pot over the 1k resistor this time so I can dial in the maximum timing without causing a miss.

I purchased the pot, switch, and a small project box at a local electronics shop for ~$5 total, but it looks very similar to this over the counter version.
Since this is a topic of interest again hopefully that info will save some search time. The topic of relocating the IAT sensor has come up as well, and the IAT extension harness mentioned above would work for that as well.

Edit: While I'm at it, here's a table of IAT resistance vs. temperature
Code:

Deg F Ohms
32 34400
76 12800
96 6600
112 4800
122 3800
128 3000
140 2400
150 2100
160 1900
165 1700
190 870
212 625

Circuit diagram
I was asked to clarify the circuit layout, so here's a quickie diagram showing the switch and potentiometer in parallel with the IAT sensor:
Yuup its the 24v timing shutter, happens on most 98.5s-02s with lots of fuel, I have dealt with this sense I did my Machs last winter, to get rid of it you need to put a warmer (190) t-stat in, and you need to fool the IAT sensor to think its warmer than it is, this can be done with a potentiometer, that way it can be set at stock voltage for cold weather starts, and then switched for hard driving, here is some more info

For those considering the IAT mod, here's some info from a previous thread describing what I did:
Quote:
First I verified timbo's suggestion by purchasing a 1k ohm resistor (1/2 watt for the thicker leads so it plugs into the connector) for less than a dollar and
bypassing the IAT sensor. The miss was gone, but cold starts were an embarrassing challenge. Recently I purchased an IAT extension harness and modified it to place a potentiometer & switch in parallel. The purpose of the extension harness was solely to avoid modifying the factory wiring harness. I placed the potentiometer and switch in series with each other, and the pair is wired in parallel with the stock IAT sensor. With the switch ON/closed the pot reduces the IAT resistance (tells the ECU the intake air is very hot so it pulls timing) and alleviates the miss. With the switch OFF/open it's the same as stock for cold starts. I didn't want to bypass the IAT altogether so the ECU will be able to verify that the intake grid heater is working. I also went with a pot over the 1k resistor this time so I can dial in the maximum timing without causing a miss.

I purchased the pot, switch, and a small project box at a local electronics shop for ~$5 total, but it looks very similar to this over the counter version.
Since this is a topic of interest again hopefully that info will save some search time. The topic of relocating the IAT sensor has come up as well, and the IAT extension harness mentioned above would work for that as well.

Edit: While I'm at it, here's a table of IAT resistance vs. temperature
Code:

Deg F Ohms
32 34400
76 12800
96 6600
112 4800
122 3800
128 3000
140 2400
150 2100
160 1900
165 1700
190 870
212 625

Circuit diagram
I was asked to clarify the circuit layout, so here's a quickie diagram showing the switch and potentiometer in parallel with the IAT sensor:

IATcircuit.jpg


Again, with the switch open it's the stock configuration. Close the switch and the potentiometer is placed in parallel with the IAT sensor. The equation for determining the combined resistance of the potentiometer and the IAT sensor (ie. what the ECM sees) is:


Refer to the IAT calibration info in my previous post to convert resistance to temperature.

Once again, if you purchase an IAT extension harness you can tap into that to place the switch/potentiometer in parallel with the IAT sensor while leaving your stock harness unharmed. That's up to you.
Attached Images

This info was posted by EHrul on TDR, here is the full 8 pages if you wanna read it

Turbo Diesel Register
 
I'm looking at the circuit, which looks simple enough, and I'm looking at the resistance/temperature chart, but you're saying that you used a 1k ohm resistor, but you're showing resistance factors in excess of 30k ohms..what am I missing? The other thing is I can't view the thread on TDR, since I don't have a subscription, but do you have a PN or place where I could buy the IAT extension harness? Any pics of your setup? I'm definitely interested, I think I might have sent you a PM on CF, or someone, about this same thread, to try and get more info about the mod.
 
I thought the point of the MAP hookup was the reference by which the timing was added. This would make sense because when you unhook just the edge wiring harness from the sensor itself, it makes the edge think its in full boost stage which would automatically give full fuel. I have never tried or even thought to try with not hooking up the MAP harness at all and leaving the trucks wiring plugged into the MAP. Guess I'll have to try that to see what'll happen. What is the canbus plug for then? I thought it was what communicated with the pump so the pump would know what to advance the timing to, and its signal was referenced by what the edge sees coming from the MAP harness. I don't know. I'd sure like to use the edge as a fuel only box to have that other option.

???
 
The MAP would have a small part in deciding timing advance. The CAN bus plug is, and I may be wrong on this, where the comp pulls other engine parameters such as IAT, timing, etc. and then modifies and returns those signals to the ECM.
 
So as long as the canbus plug is connected, there will still be timing regardless of the MAP harness connections right? Wouldn't that mean that it would not be able to be made into a fuel only box? Would it even work with the canbus connection unhooked?
 
Adrenaline won't I tried stacking a TS mvp with ADR hooked inline map sensors and using the wire tap, I didn't work!

I thought about tapping the wires in into the mvp harness to see what two boxes hooked to the data link would do, and maybe turn the timing on the ADR off,
but i think they would fight each other and throw the truck into limp mode
 
Mine has always got a timing rattle(its what i call it) with any of the edge tapping boxes, never did it with the FMS or with the adrenaline, mine always rattled with and it did not matter what temp it was, stopped using edge stuff, rattle stopped!!!
 
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