Jeep Strokers

Those plugs look awfully cruddy to me!, the porcelain at the tip should be just about clean WHITE, although the pictures in the AUTOLITE catalog claim that the redish/pink is "normal", it gives no further description than that?

So then what do you think my plugs are saying?

They dont look abnormal to me... no crazy deposits, no sooting or melting or any of that. The timing line is just about in the middle of the ground strap maybe a little advanced.

It does look like the heat range may need to be increased though... as the plug is only showing 1.5-2 threads burnt.. and from what i cant tell 2.5-3 is best. I might leave it alone though.

Maybe this is just from a weak ignition??

Muad'Dib wrote:So then what do you think my plugs are saying?

They dont look abnormal to me... no crazy deposits, no sooting or melting or any of that. The timing line is just about in the middle of the ground strap maybe a little advanced.

It does look like the heat range may need to be increased though... as the plug is only showing 1.5-2 threads burnt.. and from what i cant tell 2.5-3 is best. I might leave it alone though.

Maybe this is just from a weak ignition??

I know this might sound crazy, but if you are dumping fuel to try to fix the lean issue, you could be misfiring, which would cause a lean reading on your wideband because of the unburnt 02. Just a wacky alternative to your problem.... it happens

Do you need any help/ info with the Arduino? I am going to do a write up on it if I ever get
my engine in. I have completed the electronics and have quite a few communications with Phil, the "inventor".
I see from your profile that you are in IT so you probably know way more than me about it.
But, if there is anything I can do to help, I am more than willing to be of any assistance .
J.B.

I cant really tune for anything but WOT with this thing.. so all ive done is adjust for 13ish AFR at WOT and thats it. The rest is done by the computer and the input it gets from the sensors.

I also wonder if this is caused by too big of a TB opening... or maybe its just "too much" for the RENIX computer and i will need to use a custom ECU like Megasquirt or similar (which would SUCK!). Either that or my ECU is bad.

Shit i just dont know anymore... its a weird problem that no one seems to have any input on.

That is all any of use with a stock PCM can do, tune at WOT. The computer should handle the rest, but its hard to see what your PCM is doing/seeing. When was the last time you replaced your O2 sensors? Also, have you tried to hook a multi meter or oscilloscope to the various sensors to see their output while driving?

The plugs still concern me, however maybe its the camera throwing the color off. Google some plug pics and compare yours to them.

SilverXJ wrote:That is all any of use with a stock PCM can do, tune at WOT. The computer should handle the rest, but its hard to see what your PCM is doing/seeing. When was the last time you replaced your O2 sensors? Also, have you tried to hook a multi meter or oscilloscope to the various sensors to see their output while driving?

The plugs still concern me, however maybe its the camera throwing the color off. Google some plug pics and compare yours to them.

Ive tested all the sensors and they are reporting as they should. The only ones i cant test are the CPS and the Stator. The Stator only really applies to starting \ cranking so im not concearned with that sensor (i crank\start fast for a RENIX jeep).

The CPS is a brand new HA unit.

RENIX only has one 02 for the computer. It was purchased new when i built the engine..

Today, when i pulled the pigtail for my 02, all i saw was the +5 and not the +12 from the relay. Would my 02 heater cause these issues?

As far as the plugs, the only thing that i can find thats strange is the pink color. The plugs might be a little more "brown" then i would like. I would prefer they were gray.... but everything i can find says brown or gray is "ok".

carcraft.com wrote:Today’s pump gas may use additives that cause a discoloration of the plug core nose; they could be pink, purple, or blue. Do not consider this coloration as an indication of heat range when reading spark plugs.

Worked all evening on this issue with no avail.

The only thing that is kind of making a difference is adding fuel back in with the AFPR.. but this causes me to be way rich at WOT (approx 11.5-12) and then drops off the wideband by the time redline comes around.

Im starting to think a custom ECU is on order... or maybe an 02 clamp... this might fix my lean tip in.


Suggestions?

How does the renix determine AFR? Is it like OBD where it has a closed and open loop and shoots for 14.7:1 in close loop?

You questioned the TPS and then you said it tested fine. What were the values for the test? Did you check it with an analog meter?

SilverXJ wrote:How does the renix determine AFR? Is it like OBD where it has a closed and open loop and shoots for 14.7:1 in close loop?

You questioned the TPS and then you said it tested fine. What were the values for the test? Did you check it with an analog meter?

I actually dont have a analog meter, but i tried 4 different TPS's i have... some which were known good... 1 was brand new. No difference for all of them.

I even tried adjusting to the ECU side of the TPS instead of the Transmission side. The only thing this changed was the shift points for the Transmission.

Disconnecting the 02 or 02 relay causes RICH condition at about 12-12.5 at all times.

Im not sure how the RENIX adjusts the AFR... my assumption is that is is based on the inputs from the MAT(or IAT), CTS, MAP, TPS and 02 sensor when in closed loop.... when open it does it off a prebuilt mapping. (my assumptions here). If thats correct this would seem to point to a sensor problem.. but they all check out with the multimeter (except the TPS since i dont have a analog). MAP is brand new also.

wonder how hard it would be to convert to to ob2 and just keep the stock gauges

Would probably be easier to do megasquirt or similar.

i was originally looking at doing a megasquirt myself but i think i'm going to try and see if i have any issues with the renix

The only problem i am having with mine is this lean tip in issue... and just recently i started to have a super low idle... but those are the only two issues i have.

In my case, i think one of two things could be happening.

1.) I have a bad computer ( i thought i read on NAXJA awhile back that there were a few bad ECU's found .. something with the injector circuit..)
2.) The Renix ecu just cant keep up with the stout engine. Makes since that the ECU cant respond fast enough to keep up with the sharp throttle opening of my Dodge Dakota TB. Im sure as soon as the throttle plate opens it needs tons of fuel to keep up with all the added air thats coming in. It cant do it fast / sharp enough so i am lean. However when idle or cruising, it has no problem. The same goes for WOT. (this is complete speculation on my part).


I wish others had more input on this... but it seems all are just about as stumped as i am.

Im hoping once i get the Ardiuno hooked up (just need to finish building it) then i can see raw data at the ECU and possibly find a culprit. (not looking very promising though)

Which megasquirt system should i consider?

i was looking at ms2 it seemed to have everything needed and was very upgradable. ms1 was suggested by a couple folks because of the $12 processor so it would be cheap to fix if you screwed it up but i liked the specs on the ms2 better and ms3 was still being tested so i didn't want to mess with it