Fuel Injection - Sputtering Issue

[Z_Rac3r]

Hey guys... so I know I've been slacking lately and haven't been around much. I've been super busy and gotten a lot of progress done on the Z but I've run into an issue I'm racking my brain on.

 

Sometimes the car runs smooth and sounds amazing, then goes back and fourth between running really rich and losing cyl 1 (in the front of the car), to being smooth again.

 

I've checked all the spark plugs, all the wires, the distributor cap, the valve timing, I'm not sure what else to check... I thought it could be a stuck open injector for the running rich issue, but that was before I figured out cyl 1 was dead off and on. I dont think its a fuel issue because its getting the right amount of fuel... its just not igniting in Cyl 1 sometimes. Thats what made me think it was a spark issue but I've checked the whole system and its perfectly fine. So it has to be air flow or something but the biggest problem I have with troubleshooting it, is that it goes back and forth, sometimes everything runs amazingly smooth. This changes while I'm driving too, its not like sometimes I start it and its smooth and sometimes its just crap, its switches back and fourth in like 15 seconds.

 

As I've said before I haven't worked with Fuel injection too much, carburetors are my forte.... any pointers? Could it be something as simple as a dirty sensor? what would you guys check?

 

I wanted to get her smooth before this weekend... Anyone else going to the Z meet. :(

[datzenmike]

Megan, here's a great article for removing intermittent EFI problems caused by the air box. The flap door contact against the variable resistance track tends to wear a groove in it and give the wrong input to the ECU. This also shows how to enrich or lean the mixture through the range.

 

http://www.geocities.com/jfairladyz/AFMrebuild.html?1144191577198?200922?200923

[Z_Rac3r]

great find, thanks so much.