Plug reading

[LakeAnna]

Dave like I said the map sensor had one low voltage code once and we cleared it. Never came back.

The temp sensors I don't know if they are the plastic or metal jobs.... have to look in the morning. Get the old trusty steven's instrument out too. It's running at 110 on the smartcraft in 70 degree water.... seems cold to me.

 

[chad202]

You can ohm the temp sensor. The ohms should be steady. Typically when there bad the ohms will continue to rise or fall until showing open or close or the ohms will just be very noisy and not lock in.

 

[SLOmofo]

Best to swap in a known good Map sensor, is what I meant.

 

[allimax]

This sounds like the exact same problem Dave was having with his 225X motor the other weekend when we had a get together on Raystown. He had a set of the original platinum plugs still and after they were installed the problem went away. NGK no longer makes the platinum (they upgraded them to the iridium.) I called NGK's hot line and they said this was the first they have heard of a possible problem. The iridium's should be a better, longer lasting plug, yea there're pricy, but how do you explain the exact, original, designed for this motor, spark plug fixing the problem? If you get things figured out, please post and let us know.

 

[LakeAnna]

Got a map sensor on the way and headed to the shop to find my meter...

It's fouled 4 plugs as of yesterday and they where all new with about 30-40 hours on them. Meanwhile I am picking up some Bpr8es to throw at it until I figure out what's up. The fouling is on different cylinders each time...

Killing my Big end numbers having to carry around a case of plugs and socket!:twisted evil

 

[allimax]

Hey Chris, I understand your in sync with Dave on his "X" motor fouling issue. The temp sensor sounds real possible, I didn't know you're dealing with 3 of them on that motor but I can see it. Keep us updated.

 

[David Lanham]

I have a 2002 225X with near 400 hours. I

 

[ssv1761982]

Thanks for the info Dave. I pondered going one step hotter on the plugs.

 

[LakeAnna]

Dave I sent you a pm...

I got a set of 7's today and 8es to use until I figure it out.

 

[suicidealli]

They are Iridium ix BPR8EIX. NGK likes them too.:cuss

Okay here we go...

If that is one hard run it is pig rich!!!!!!

Roy

 

[LakeAnna]

Roy those are not from a hard run... and it's way beyond pig rich. It's foul, carbon foul wet whatever you want to call it. Hopefully this evening I can ohm test the temp sensors and the map sensor should be here today or tomorrow.

Mine is an 04 so it has the newer (brass)temp. sensors already. The DDT only showed one fault and that was a low voltage reading from the map sensor. Everything else was normal according to the ddt anyway. The ix plugs just seem to foul pretty easy regardless of how you run the engine. The oldest one in it now that has not fouled might have 35 hours on it. I put 6 new Bpr8es in it and numbered everything since it seems to foul on any cylinder and either bank in no particular order.

This spring I had the injectors cleaned at Brucato and put new reeds in while it was down. It has new filters and lines so fuel delivery is not an issue for sure.... If I run the **** out of it, no fouled plugs. If I try to carry my daughter down the river at 2500-4000 rpm and idle any length of time it seems that is when it happens.

 

[catfish123]

I find this all interesting as I had 323 hours on my 225X without ever fouling a single plug. The NGK BPR8EVX plugs were all I ever used so that may be the difference. The motor Dave has now is the motor I did have.

 

[LakeAnna]

I never fouled one either until this year with the eix... sooooo maybe there is a issue with those in the X. TBD

 

[GotMyAlly]

It's running at 110 on the smartcraft in 70 degree water.... seems cold to me.

That's about what my X always ran, IIRC.

 

[TBuck2003]

I would try 1 heat range hotter as mentioned...

 

[suicidealli]

You can always run hotter plugs, but I don't like to. I try and run the coolest plug I can get by with. I would also check fuel pressure. More than one way to skin a cat. Back before everybody was programming custom fuel curves, We ran adjustable fuel pressure regualtors to lean things out a little. I have also seen many regulators have different fuel pressure, even with 260, 280, and drags. JMO

Roy

 

[LakeAnna]

After testing the temp sensors and finding them to be within spec. I put the new Map sensor on and everything seems good thus far. I've driven it about 2 hours total at varied speeds and idled a bunch also. I have 6 fresh plugs in it now that have lasted since the new sensor.
Thought while I was fooling with I would do a comp. check. The results showed the right bank to be about 5-8 lbs. down from the port side. With my gauge it was around 125 and as low as 118 or so on two holes. Leakdown shows 6-8 percent so from what I was told this is about average for this engine.

Hard to believe the sensor could have been the issue but it's running fine. I noticed the new sensor had different numbers than the original.... maybe it's better. I know for sure it was a heck of a lot cleaner.

So, Seems the map sensor with it's low voltage code was in fact the problem. Hurray! I managed to get 95.8 out of her this evening in the humid thick air so it must be fine.

 

[ssv1761982]

I wonder how the plugs look now. It could be a good idea to get a baseline of how they should look. Glad to hear you have it running again.

 

[SLOmofo]

Yep, pull the plugs. Get a light and look deep into the plug, down almost at the bottom. See what color you have. Another is look at the ground strap, see if it looks fairly uniform across it's length. No blistering.

 

[TB21]

I'm very curious to know how you do a correct plug read on an Allison? The only way to get a true plug reading on any engine is to run up to speed and cut the power instantly "which will get you hurt in an Allison" and pull plugs for the inspection without starting again. If you start and idle back to ramp and on trailer you just killed an accurate plug read.