KFtransam

Having some trouble, I've had a thread going about my new chandler opti and the problems that have recently arisen.

I ran through the opti and icm electrical test procedures on your site to find that the ground wire on the opti connector (also at the harness end) was reading .96 ohms.. Almost no ground.. So out of curiosity I checked ground to the intake mani, consistently .16 when not running. Though when running I had -1.15 to the block... The frame and body are reading 0ohms. I'm not sure what's going on here but it's something funky and I'm hoping you can help me out


Car runs fine when you first fire it for about 2 minutes. Then gets really choppy and rough. You can kill it and directly after start it and it will again run perfectly normal for a couple minutes before dying down again

DisturbedTA

iTrader: (3)

Have you checked fuel pressure that's what mine is doing and its my pump

NewOrleansLT1

I think he's at lunch, but I'd check the ground straps to the block or check for a chafed wire on the opti harness also hook up a fuel pressure gauge and monitor the pressure

KFtransam

I monitored the pressure, everything is as should be and within specs.

I'm thinking this is a ground issue as you said.. I'll have to check ground straps. Where are they all located?

shbox

.96 ohms is not "almost no ground" and how do you get a reading of negative 1.15 ohms? Ohms are not neg and pos. I would not consider the .96 ohms reading bad. I think I have measured this before and gotten something in the .7-.8 range. IDK why you have so many threads going on for this (duplicate of this one, even). Hard to keep up with. If you want my attention about a thread, email me and ask me to look at it.

KFtransam

I scratched my head about the negative ohms aswell.. And if no connection on the ohms meter is 1 and full continuity is 0, than I figure .96 is a very weak ground and the .16 on the block isn't bad, but also isn't fully grounded.

Either way, I was not getting the value that was specified in the procedure on your site and I was hoping you could provide some insight.

shbox

With the leads disconnected, the reading really means nothing. Like I said, .96 is likely ok, if I remember correctly from looking at mine.

KFtransam

Okay thanks..

So should I chalk this up to being a crap opti?
I've run out of other options and my final step is to order an ALDL and download datamaster.

Get an idea what's going on because this situation where it runs Okay for the first minute has me baffled

KFtransam

Drive it home from the in laws today, runs fine for the first mile, starts to get choppy and no longer driveable. I kill it and instantly restart it and it runs fine for the next mile home... I don't know what this could be

BTC

Maybe something is going on with the O2 sensors.

shbox

Unless there is some definite diagnostic data to point to something, there is going to have to be a hard failure to determine what it is. Chasing intermittent problems is difficult.

KFtransam

I thought this was a possibility also, so I unplugged the MAF to force open loop and the problem still happened.


This is a rather difficult scenario to diagnose.
I'm hoping datamaster will help point me to an explanation

KFtransam

Well, I got my ALDL cable and installed tunerpro rt. finnally got arround to setting it up and doing some data loging tonight.

I have a pretty good idea of what everything means, but I don't see anything that really jumps out at me. Although, I do see left blm at 127 and right at 132 with left o2 at 360-380 and right o2 jumping between 120 and 860

It's running okay on start up in open loop. The right o2 heats up and is "ready" where the left o2 keeps jumping back and forth between "ready" and "not ready" cause it to jump between open and closed loop.

At idle it will finnally settle in open loop. Though it still runs choppy and attpempts closed loop if I snap the throttle.

I don't know enough to say what this really means, could I just have a bad o2 sensor? Is there something more going on?

If you need more info, I've recorded a couple logs

Thank you again

shbox

As a starting point and from what you just said, there is some sort of issue with the left O2.

KFtransam

This is what I figured, I got underneith the car to check the wiring. Everything seemed okay, though it's hard to tell without getting it up in the air and really going through it..

Now It's running okay, and intermittently throwing fits. I can't help but feel like I'm burning some wiring on that left o2

shbox

You could swap the O2s and see if the trouble follows. Then you will know if it is the sensor or not.

KFtransam

Good call.. I may try that out tonight

LT1DG

How's it going man, I love your site and very informative stuff on the lt1. But i need you to check out my thread to help me out with this issue. Thanks. https://ls1tech.com/forums/showthrea...6&goto=newpost