madkaw Posted June 14, 2009 Share Posted June 14, 2009 Okay guys i am trying to do this the right way. I got a better multitester and I have my FSM to guide me. I started right from the beginning to do the component checks of the FI in my 81zxt. I'm starting to get worried that none of my ohm tests at the plug end of the ecu are good. I checked my throttle switch at the ecu and it fails, but at the component ,I was able to get it to adjust and test. Same goes for my AFM. I can get the correct reading at the AFM, but not at the ECU. I can't believe all my connectors are bad and I did clean them once already. I did the inspection preparation with only one reserve, i wasn't sure what they meant when refering to the S terminal at the starter( I disconnected the spade terminal) . I did ground my O2 and disconnected my negative terminal--am I missing something. This car has 91k miles and is pretty clean, even the engine compartment is clean. As far as connectors, I replaced the one to my CHTS and I get the same problem of good component-bad harness. I was going to replace my TPS connector, but I have a 3 hole type and my replacement connectors are 2 holes. My harness connector(s) are different then the FSM shows. I actually have 3 different plus going into the ecu. The car idles rough and stumbles a bit on acceleration and that is why I am trying to go thru everything on this car. Would the car even run if the ecu was not getting any readings from the components? Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 14, 2009 Share Posted June 14, 2009 (ObiWan Kenobi Erethereal Voice) "Trust your instruments madkaw..." The FSM give guidance on the steps to take if loop test fails, and component test does not. CLEAR guidance. If multiple failures are occurring, look for something like a .22 calibre hole through the wiring harness, or a spot where a PO buttspliced the entire harness back together. Don't laugh, BOTH of these are reasons I found for cars either not running, or that would NOT get rid of a persistent miss and kept failing smog. For the .22, the car had to be parked with the hood open, the inspection lid up, and the gun pointed down at almost a 60 degree angle to have a bullet go through the top edge of the resistor pack, then punch through the firewall and go through the EFI harness, and end up on the floor. "No wonder it wouldn't run" FYI that harness was repaired and has run in two LeMons events thus far! Quote Link to comment Share on other sites More sharing options...
madkaw Posted June 15, 2009 Author Share Posted June 15, 2009 Well there is no bullet hole in my harness, but I wouldn't be suprised to find one. Actually the second day, or round at troubleshooting was more successful. Understanding how to use my ohm scale on my new multimeter was a big help:redface: I also had an issue with the numbers for the wires not being the same a s the FSM since the AFM is a rebuild from msa-I guess. The CHTS would only test properly if I used a ground from the ecu harness, not the body ground they asked for, which I thought was strange. Looking at the wiring schematic I found that the AFM and CHTS ground are shared so I used that pin as my ground and the CHTS would test properly. I was also able to successfully adjust my TPS. It was way off of FSM specs, but I won't know how well adjusted until I start her up again.I still have other checks, but I have a bigger problem to deal with now-oil in the intake system. Time for another thread:mrgreen: Quote Link to comment Share on other sites More sharing options...
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