MayDay!! - Hard Accel Killed Idle

[AnotherOldJeepGuy]

[AnotherOldJeepGuy]

I just did soap test #2, I suds-ed up all along the top of the area where the manifolds connect and again saw no signs of any bubbles being blown, or soap being sucked in, and also no sign of RPM changes with the soap and then as I rinsed it off.  This is not too surprising since the water testing has already proven to not show anything, but it was another place to try the soap that was easy enough to get to.  Now I need to let it completely cool again and see if there are other places I can soap up and try again.  I am not loosing track that everything was great until the "maneuver incident" so although I cannot yet find any crack, a physical issue still seems more likely (at least to me) rather than some control that failed coincidentally at that same instant.

 

I have read over the distributor index posting at least 4 times at this point, and have not come to a sufficient understanding of that task to pursue it.  It may be beyond the extent of my mechanical grasp, time will tell.

[Gojira94]

REM is on the way via USPS, should be there Saturday. I also enclosed a new NTK sensor. It's one of the newer metal body design. I ended up not using it since I found a ceramic body NOS AC Delco 25176716 that gave me a perfect 6.2 ohms on the heater grid circuit. I measured the heater grid circuit resistance of the NTK and it's just a hair below spec at 4.8 ohms but I thought it might be useful for troubleshooting.

[AnotherOldJeepGuy]

On 6/3/2026 at 1:04 PM, Gojira94 said:

REM is on the way via USPS, should be there Saturday. I also enclosed a new NTK sensor. It's one of the newer metal body design. I ended up not using it since I found a ceramic body NOS AC Delco 25176716 that gave me a perfect 6.2 ohms on the heater grid circuit. I measured the heater grid circuit resistance of the NTK and it's just a hair below spec at 4.8 ohms but I thought it might be useful for troubleshooting.

Awesome, I'll be watching the mail!  Thanks again!

 

 

Edited Saturday at 01:11 PM by AnotherOldJeepGuy
6/5/26 - Captured Code Desc and Gauge Readouts Summary Pages for printing, and study!

[Gojira94]

https://nickintimedesign.com/rem-gauge-readouts/

 

We'll want to see MAP, VAC, ºFWT, VLT (system voltage while running), TPS at idle, vO2 / mVo, A/F, vHT, ST, LT, SYN, maybe a few more.

[AnotherOldJeepGuy]

OK, I got some info.  I am far from an expert at using this tool yet and I am trying to figure out the button driven menu system, but my first attempt I get the following:

 

REM installed, Key ON, engine not yet started.

CODES:

-REM CODES

--No REM Codes

-ECU CODES

--Injector 1 Open (this was not consistent, I later read instead I2 and I3 Open, but not I1)

According to the documentation on the website, "ECU does not detect Injector # wire has a ground path"

-TCU CODES

--No TCU Codes.

-ABS CODES

--Not Available.

 

Then with engine started.

CODES:

-REM CODES

--Loop Fault Lean

According to the documentation on the website,

Possibly faulty o2 sensor, weak fuel pressure, other fuel system imbalance.
– TIP: This code is more common during cold weather starts as the first Closed Loop attempt may fail due to the Cold Fuel Enrichment value still being too high. This code can be ignored if the 2nd closed loop attempt succeeds

-ECU CODES

--No Injector 12V** (This was consistent, but is to be ignored**)

--KO Tests Not Run

**According to the documentation on the website, if "No Injector 12V" is received along with "KO Tests Not Run" it can be ignored.

-TCU CODES

--No TCU Codes.

-ABS CODES

--Not Available.

 

Once I can get more familiar with the menu I'll try to grab the other items listed by @Gojira94.

 

 

 

[AnotherOldJeepGuy]

I collected everything I could find that lined up with the "REM Gauge Readouts Summary" with engine OFF before I got chased in by rain.  I got the reading through the menu  HOME->DIAG->READINGS and noted them in a copy of that list which I have attached here.  I got an error when I attached it, or at least a message, telling me that pdf was not supported?  I am guessing with no knowledge that the error means it calling be displayed in the thread, but I am assuming the attachment can be opened by anyone that can open a PDF.  Can someone confirm it can be opened so I know posting a PDF works or does not please?

 

Looks like there are other sub-menus but I don't have any REM for Dummys book to follow to know what other buttons I might need to push or in what order, so I am hoping this gets me where I need to do.  I'll update and repost with a version annotated with the same reading with the engine running after the rain.

REM Gauge Readouts Engine Off.pdf

[Ωhm]

PDF good by me. Must be signed in.

[AnotherOldJeepGuy]

Thanks for that confirmation, I figured but the warning was not clear!

[AnotherOldJeepGuy]

Rain Stopped so I collected the engine running dataset and added to PDF.  Note that since TSP was showing low I adjusted it to 17 before collecting the additional information.  My expertise doesn't let me identify good/bad but I don't see much that is obviously way out of line based on the REM documented expectations.  I guess I am most curious about the readings that kept moving around, because the movements coincide with the engine revving up and down during idle, and it didn't use to do that (IIRC).

REM Gauge Readouts Engine Off-On.pdf