After swapping my stock Rochester injectors out to some Bosh injectors from a Musting GT (supposedly...), I found that my car was difficult to start, ran very rich at all times, and got about 18 MPG on the highway (and that with a stock 350 TPI and 2.77 rear). So I decided today to pull the Bosh ones out and temporarily replace them with the original Rochesters. In reality, there was never a pressing need to replace them in the first place other than that I was trying to be "proactive" and replace them before they failed (as they have a reputation of doing so). The plan is to send the Bosch ones off to Rich at Cruzin' Performance to have them flow-matched and flow-tested so I can know what I *really* got from the guy on E-bay.

Well, I just finished putting the Rochesters back in, start the engine up, and now I have a miss on at least one cylinder judging by the idle quality. I didn't touch any of the ignition components changing the injectors, so I don't expect that it is a spark-related miss. I have re-checked the connections to each injector and they all look fine. I also checked the coil resistance on each injector before reinstalling them and they were all within 0.3 kOhms of each-other with an average of about 16.3 kOhms (I think kOhms; not sure). Lastly, I hit each end of each injector with WD-40 and sprayed them all out before I re-installed them just to make completely sure that no junk that might have gotten inside while they were sitting in my garage remained.

So, at this point, I'm not really looking forward to spending another 4 hours pulling the intake off again and un-doing what I just did today. My only *guess* at this point is that possibly the pintles on one of the injectors is stuck shut and not allowing fuel into the engine. Does that sound reasonable?

Anything else I should check before I have to go pull everything again? Would it be terribly bad for the engine if I let it idle/run with the miss and just hope that it goes away eventually?

Many thanks in advance.

 

Check to see if you might have switched injector harness conections.

 

I wouldn't be too worried about the possibility of exchanged connections, since the system is batch-fire. I'd be more concerned about contaminated injectors or damaged 'O' rings. If you have a decent tachometer you can perform a power balance test to determine which cylinder(s) is not firing properly. Once isolated, you can analyze from there.

It probably will not cause any harn allowing it to run with a dead cylinder, unless it is because there is no spark on that cylinder and it is dumping raw fuel to the exhaust.

 

You don't think there will be any problems with "balance" issues running with a dead cylinder (not mass balance but "power" balance)? I can feel the whole car shake when I step on the gas even a little.

I've already sent off my injectors to Cruzin' Performance and this problem should be fixed by the time I get them back and put back in. However, if I could run my car with the dead cylinder just to get to work and back (and not risk permanent damage), that'd be a major help.

Thanks

 

Running with a dead cylinder due to lack of fuel will probably not cause any significant problems. You may experience an oil fouled plug on that cylinder by the time you get the replacement injectors installed, but that would be about it. Don't go racing, just drive it normally.

 

Well then, I'm sold!

Sweet, no more getting car-pooled around. Thanks Vader.