Hesitation completey at a loss

[Hipster]

Brand new “nos” ignition with pertronix flame thrower coil and D.U.I plug wires with stock delco plugs.

new doesn't mean good, ohms tests won't tell you if the ignition components are up to the task. Coil rise time between cycles etc. One misfire can take ignition components down. Data gives the picture. I'm kinda spitballin' but it sounds like a lazy coil.

 

[Schurkey]

Does the TPS signal change smoothly as you slowly press and release the throttle?

Does the EGR diaphragm/pintle move smoothly when you gradually apply vacuum? Are the EGR passages clear?

Does the electronic spark advance work properly? When you timed the engine at "0", did you have the timing connector separated? Did you re-connect that timing connector afterwards, and clear the code?

Does the timing retard momentarily, then advance to what it was, if you tap on the cylinder head with a small hammer? In other words, does the knock sensor, knock sensor harness, and KS electronics work properly?

Is the magnet on the distributor shaft cracked?

 

[Jksconny]

Wow, you have done EVERYTHING right so far!

In case I missed it, have you checked for intake manifold vacuum leaks? Usually that's an idle issue but with everything else new or substituted for known good items your getting low on options.

How about the vacuum brake booster? Could be cracked and sucking air or brake fluid at a certain manifold pressure/volume. Just thinking outside the box here.

I have 20 hg vacum, I have sprayed everything Hoping to find something still nothing.

 

[Jksconny]

new doesn't mean good, ohms tests won't tell you if the ignition components are up to the task. Coil rise time between cycles etc. One misfire can take ignition components down. Data gives the picture. I'm kinda spitballin' but it sounds like a lazy coil.

I will swap coils from good runner to mine, and let you kno, thanks for the tip

 

[Jksconny]

Does the TPS signal change smoothly as you slowly press and release the throttle?

Does the EGR diaphragm/pintle move smoothly when you gradually apply vacuum? Are the EGR passages clear?

Does the electronic spark advance work properly? When you timed the engine at "0", did you have the timing connector separated? Did you re-connect that timing connector afterwards, and clear the code?

Does the timing retard momentarily, then advance to what it was, if you tap on the cylinder head with a small hammer? In other words, does the knock sensor, knock sensor harness, and KS electronics work properly?

Is the magnet on the distributor shaft cracked?

I have done all those tests like you described, egr I put truck against tree in drive and move throttle to see egr in action and it does what it is suppose to, knock sensor same results. Brand new old stock delco distributor.

 

[Jksconny]

I have done all those tests like you described, egr I put truck against tree in drive and move throttle to see egr in action and it does what it is suppose to, knock sensor same results. Brand new old stock delco distributor.

I think I’ll swap distributors From good truck to mine, thanks for tip

 

[Jksconny]

Android phone and ALDLDroid ($20) might be the simplest in the sense that you don't have to mess with COM drivers in Windows.

I had success datalogging using the free trial of Tunercat once. I would say the majority of people use Tunerpro so a Windows PC with Tunerpro might be the most commonly public supported path but I never used it.

I’m assuming any cheap android on eBay would work?

 

[Hipster]

I will swap coils from good runner to mine, and let you kno, thanks for the tip

Well, with Schurkey on this one, fuel is good, you say sensors good, no vacuum leaks, etc so leaning towards ignition. Proper dist. installation, not 2 or 3 teeth off, no cracked porcelains on plugs, wires not shorting though jackets or boots, the fact that ignition and pick up coils can't be ohms tested and determined good.
Some new replacement stuff only last 2 or so years etc. As per Schurkey, is the advance coming in?.

 

[Jksconny]

Well, with Schurkey on this one, fuel is good, you say sensors good, no vacuum leaks, etc so leaning towards ignition. Proper dist. installation, not 2 or 3 teeth off, no cracked porcelains on plugs, wires not shorting though jackets or boots, the fact that ignition and pick up coils can't be ohms tested and determined good.
Some new replacement stuff only last 2 or so years etc. As per Schurkey, is the advance coming in?.

I purchased a new old stock gm distributor from a guy ( I believe I got the info on here before I joined) online who was sitting on a bunch of nos oem distributors just to rule it out after checking the other two I have 8000 times. I spent the big money on DUI cables just cause I have been trouble shooting for so long my old cables on and off on and off, so to rule cables out I got the most bullet proof ones I can find. Spark bugs new this spring stock delco stuff. I have advance wire hooked up, what’s the trick to making sure advance is working?

 

[Jksconny]

I purchased a new old stock gm distributor from a guy ( I believe I got the info on here before I joined) online who was sitting on a bunch of nos oem distributors just to rule it out after checking the other two I have 8000 times. I spent the big money on DUI cables just cause I have been trouble shooting for so long my old cables on and off on and off, so to rule cables out I got the most bullet proof ones I can find. Spark bugs new this spring stock delco stuff. I have advance wire hooked up, what’s the trick to making sure advance is working?

I have hit the block with the brick plugged in and it said knock sensor works