[Gmecm] Re: +AFs-Gmecm+AF0- How to wire Timing Bypass on 4-Cyl 151 Iron Duke?

[David Allen]

  Both my GM-ECM controlled cars have the +ACI-set-timing+ACI- connector you describe.  It's simply a break in the +ACI-bypass+ACI- signal wire.  Doing exactly what you said (making your own inline connector that can be disconnected) would be what you need to do.
David


----- Original Message ----- 
From: +ACI-Aphelion79+ACI- +ADw-aphelion79+AEA-cox.net+AD4-
To: +ADw-gmecm+AEA-diy-efi.org+AD4-
Sent: Thursday, August 03, 2006 11:13 PM
Subject: +AFs-Gmecm+AF0- How to wire Timing Bypass on 4-Cyl 151 Iron Duke?


+AD4- Hey, remember me? The newbie with the 4-Cyl 151 Iron Duke and the CJ7?
+AD4- Well anyway, I'm finally able to start working on my Heep again... and 
+AD4- am curious as to how to set the timing on this thing...
+AD4- 
+AD4- Now, all vehicles have some sort of timing advance... on carburated 
+AD4- engines (just spilling out how I understand it... correct me if I'm 
+AD4- wrong with anything) you unplug the vacuum advance hose and plug the 
+AD4- port as to not cause any vacuum leaks... and set the timing... on a 
+AD4- TBI'ed vehicle... there is a special wire that has an in-line coupler 
+AD4- that allows you do disconnect the signal sent to the Distributor for the 
+AD4- electronic advance... unplug that, set timing.. yadda yadda
+AD4- 
+AD4- But here's my problem:
+AD4- On a 88 Chevy S-10 Pickup, +ACI-there is a black/red wire under the 
+AD4- passenger's side floorboard that you can disconnect and then set the 
+AD4- timing+ACI-... well... I obviously do NOT have an S-10... nor any wires 
+AD4- inside of the firewall as I just spliced most of the wires off that went 
+AD4- to the fusebox... and I've followed diagrams of the ECU pins and could 
+AD4- not find any mention of this special wire... However... on GM-ECM I 
+AD4- found a schematic for the 7747 ECM 
+AD4- +ADw-ftp://ftp.diy-efi.org/pub/gmecm/manuals/1227747/747ecm6.jpg+AD4-
+AD4- (ftp://ftp.diy-efi.org/pub/gmecm/manuals/1227747/747ecm6.jpg) -which is 
+AD4- NOT the ECM I have... (if this information is current, got this from an 
+AD4- old post I made a while back on a different forum:) mine is:
+AD4- 
+AD4- SVC+ACM- 16198445
+AD4- Barcode:
+AD4- 866647W643273117
+AD4- Chip Inside:
+AD4- ACKD 4890
+AD4- 
+AD4- The previous link to the 7747 indicates the TAN/BLK wire right off the 
+AD4- distributor controls the timing bypass... now I've disassembled my 
+AD4- wonderfuly sexy wiring loom and traced all 4 wires that come off of the 
+AD4- distributor...and each one of them goes DIRECTLY into the ECM... none 
+AD4- have any splices in them as well or any disconnects in-line... Would 
+AD4- splicing into the wire, and creating my own quick connect/disconnect 
+AD4- in-line plug right at the 4-pin connector off the distributor be a good 
+AD4- way to do this or am I missing something? I could simply +ACI-just try it+ACI- 
+AD4- but I wanted to run this by you all first... you guys seem to know more 
+AD4- about this stuff than any of us on JeepForum
+AD4- 
+AD4- Thanks again... +ACEAIQ- By the way... the Jeep runs... haven't started it up 
+AD4- in 2 months and it fired right up... however it idles a bit rough and 
+AD4- doesn't have very much power at all... so I figured timing would be the 
+AD4- issue+ACE- I previously set the timing by luck by putting it at top dead 
+AD4- center... unplugging the whole entire 4 pin connector off of the 
+AD4- distributor -which doesn't allow the engine to run- and had a helper 
+AD4- eyeball it to 0+ACo- and plugged it back in...
+AD4- 
+AD4- Anyway, enough length on this... any other questions or things I should 
+AD4- look at let me know+ACE-
+AD4- +AF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXw-
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