Z-Car woes...looking for advice.

[Guest freakozs]

Before all of this started, my 1976 Z was running fine, but had a leaky cracked injector holder that always bothered me. So I changed it out, only removing the firewall side of the fuel rail, pulling the #5 injector, changing out the O-rings and holder for that injector, and re-installing everything just as it was. Of course, when I crank the engine, it's missing like crazy.

 

I went ahead and bought all new injectors, fuel line and O-rings, which I installed last night. I also went ahead and put new spark plugs in for a fresh start. Everything went beautifully, and once it was back together, I primed the fuel pump to check for any leaks in the hoses that might need more tightening. After finding a couple, and re-tightening the clamps, the fuel system was leak-free and ready to go. Turned the key, crossing my fingers....no such luck. Same EXACT miss as before. I checked the voltage at all 6 injector connections, and was getting .98 volts at idle and 3.6-4 volts while revving to 1k. It was a digital meter so of course it was jumping around a bit with the pulses. I also pulled each spark plug while running at 1k and could not come up with a definite culprit cylinder, although cylinder 6 was questionable as to whether there was a difference when I pulled it. I also checked the compression and came up with these numbers...

 

#6 - 141 lbs.

#5 - 151 lbs.

#4 - 151 lbs.

#3 - 151 lbs.

#2 - 156 lbs.

#1 - 149 lbs.

 

I tested with the engine warm, with all plugs removed and with a brand spanking new battery (parasitic draining problem I've got to diagnose). The FSM says that as long as your lowest compression is not less than 80% of your highest compression, then everything should be ok. If this is correct, then I should be ok on compression.

 

So, I'm not sure what is going on. It would be bizarre coincidence that the problem be unrelated to what I fiddled with changing the injector holder, but I've seen stranger things.

 

Anyone else got any ideas? The car is stuck 120 miles from my home, so I can only work on it when I can get to it on weekends...one more weekend and I think I'm gonna have to tow it.

 

Is it a possibility that I damaged the fuel rail pulling it off the first time? There is a very slight crimp on the firewall side, just before cylinder #6, but when I pulled it off last night, it didn't appear to be obstructed as I could blow through it with absolutely no resistance.

 

Please help! I'm missing some beautiful driving weather!!!

[datsun40146]

The only thing that I can think of it that mabye you unplugged one of more sensors or pluged them in, in the wrong place. Check your AFM harness plug, make sure its tight and clean. Also check to see if your theromotime and water temp switches are clean and in the right order. Also please check yout TPS sensor for full movement and lack of corrosion.

 

If all of these check out, then mabye the PO b/c of the cracked injector turned the afm adjstment screw one way ot another to make up for the lower or higher fuel coming out the injector 5. Pop your AFM open and see if it has been tampered with.