I disconnected auto tranny computer and now inbetween even light throttle shifts I get the pop like the one at 7k when you let off the gas. It is not as loud but it is there. I am sure this never happened before. There seems to be no change in performance but I noticed after disconnecting it idled higher. I shut all accessories off and used the idle adjust screw to get it back to 750. Idle is smooth still also. No popping at idle. This is an 89 GXL that was converted to manual back in september and I just took the computer out today. Is my problem unrelated to removing the tranny ecu or should I put it back in? Possibly running too rich? Thanks, Sean

 

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Did you have this plugged in the whole time!?!?! I certainly hope not! Did you remember to hook up the nuetral switch? I've converted my 89 GXL to 5 speed as well, and i was told never to leave it plugged in after the conversion. Not sure what might be causing the backfire, or pop. But it shouldn't effect the idle that I know of.

 

TEH EC-AT should be unplugged. The pop you get is from revving out the rotary then dropping a gear, so for a second it runs rich between shifts adn pops...if yo had a straight exhaust it would shoot a flame. With the old auto tranny ecu, it was set up on a slightly different map, since when the AT shifts is does so slowly, it was set up not to do that, buit it is normal for a 5sp.

Enjoy.

 

Well, that will solve any questions I'll ever have about the AT computer. Yet another future problem avoided!

 

I have no idea what you are talking about a neutral switch. Please shed some light on this. So the AT ecu was still sending the signals to regular ecu that I still had an automatic?

 

Yes, it was, if it was plugged in. Usually when you convert from an automatic to five speed you have to spend some time hooking up the reverse lights and the neutral switch because the plugs don't fit together. But, hypntyz7 already explained why your car was doing that.

 

Yeah I don't have the reverse lights and last time I had the car up I remember seeing some wires by the tranny. I'll have to look that up. Thanks for the info guys.