I'm not getting anywhere on finding the root cause. I hooked up the Moates datalogger and Tunerpro RT5 prior to getting on the highway after warm up. The most recent datalog and odf (excel) file is...

I am not set up to burn chips.

So I guess I will not be able to datalog the base pulse width or the spark advance..?...

Hi Dave, I have been trying to locate the "Hack" for the Tunerpro Spark Advance as you noted. Can you please provide a link to this?

Thank you for the update. This may all lead to replacing the distributor. It is hard for me to understand why it would run great one day, then not the next. Timing, Temp, aside. One day 9/20 running...

I also have the Moates ALDU1 & cable1. I believe Moates state that with my "older" setup that I can only use the 10k resistor. The other switch is for newer speed density reading.

So having the...

It ran well on Sept 20th. Granted it was only briefly. A couple days later, not changing or adjusting anything, a longer drive resulted in worsening performance. The next day, on a longer trip, same...

I sure hope the problem is corrected. We will see if it randomly pops up as it had in the past. I did have the battery disconnected while messing with the wiring and ECU, so thank you for this tip. I...

The howell system uses the tach lead off the distributor to signal the ECM to fire.

Update.. The injectors do not fire simultaneously. Using the timing light on number one, I could only see one...

Only to clarify, I do have a color deficiency, so I call for support to find the correct colored wire. Sometimes it takes me a bit. I have two pics, one of the distributor and one of the harness...

Thank you for clearing some of this up. I apologize, however I still have some questions concerning this. So with the initial "key on", I should be able to have a DMM on the ground side of the...

Hi Tayto, The injector D16/Blu is functional. I do have a DMM and can check the voltage. The reason for the test light was per the manuals as a quick test to check for power to ground and rule out a...

I also replaced the ECM, if the "driver" is a software driver, and had the same issue. Since then, I put the old ECM in since apparently it was okay (since no change, now I have two ECM's ... good or...

BTW, I also believe this is a "fuel only" TBI now that you mention it. This is also a Howell TBI If I have not noted so earlier.

Thank you so much for your time. I have a new ignition control...

Thank you, I was hoping the Ignition Control Module was bad. 3 months ago, I removed it and had it tested at a parts store and it was fine. I also heard that it could be bad and still test fine......

Thank you Dave, this is what I am looking for. Is this in the 89 or 90 emissions/fuel manual? I only have the B, C and G, W posts on my ICM.17057

I did, and the problem moves with the connector. Meaning injector is good, signal to the other bad.

I have to check the colors you note for sure. The continuity for both injector circuits to ECM are good. I will check for resistance for both next. Looking at the ignition control module as...

Hi Tayto,
New injectors, still one firing. Maybe I was mistaken when I swapped the connectors to the injectors previously. I am starting to question myself.
In the manual Chart A4 "Injector Circuit...

AAARRGH, as C. Brown would say when trying to kick the football.
New injectors, still one firing. Maybe I was mistaken when I swapped the connectors to the injectors previously. I am starting to...

Hi Tayto, great idea nonetheless to check for continuity. No harm, no foul!!

I did try tapping the injector housing as suggested, and also originally swapped the connectors as noted in a previous reply. Neither one produced gas out of one injector. The new matched injectors...

Hello All, I have had the injectors ultrasonically cleaned and replaced. Still runs poorly after warm-up. The data log from 8/26 is attached. I also have no idea why the sawtooth pattern exists....

Hi Tato, thank you for your input. All the basics have been checked as good or new. Cap and rotor were replaced last year with a bad connection to the ignition module under the GM HEI cap. I have...

Hi Tato, thank you for your input. All the basics have been checked as good or new. Cap and rotor were replaced last year with a bad connection to the ignition on module under the GM HEI cap. I have...

I do not have the .bin file installed at this time. I only did the .adx so I can log some data. One thing I did not do was increase the latency in the USB to 1msec. Once I do this, I can re-log data...