HELP! - wouldn't crank first try....
 

All,

Prior to starting, I checked the plugs and they looked fine. I also pulled the injectors and the wer full of varnished gas (engine was sitting for 1.5+ years). I then soaked the tips for a few hours in carb cleaner, with a little carb cleaner pooled in the back also. I didn't want to emerse the whole thing. After this, the o-ring on the tip was a stretced and a little spongy. I got some replacement o-rings from GM and installed them.

I tried to crank the engine over for the first time and didn't have any luck. It sounds like it is firing on, maybe, one cylinder. Everything else appeared as normal, the fuel pump turned on and off when expected, etc. I pulled the plugs and they wern't fouled. :bang:

I am guessing that either the injectors are still clogged or they were damaged in the carb cleaner. Some internal seals could have gotten damaged just like the ones on the outside, but wern't replaced.

Any ideas or tests I should perform to narow it down?

Thanks,

Colin

If the injectors are clogged, putting full 12 volt battery voltage (and ground) to the two terminals will "unstick" them. Hold it on there for a few seconds until you hear them click. You should be able to hear them click. If they have been sitting that long it is a good possibility that they are stuck.

Thanks for the suggestion! I tried this and I could only get three of them to click. So it appears that the injectors are definately a problem. The 5 bad ones I left for 30 plus seconds under 12V and could not get them to click. Should I wait longer? If i can't fix them in place, do you think someone could rehab them or should I just break down and replace them.

Thanks in advance,

Colin

I'm surprised 30 sec didn't do it. If they don't click within 30 sec I think you'll need to soak them more. I'd say a mixture of more soaking like you did and some more electric shock therapy would do it. You're gonna have to "worry" them loose. You could always send them out to be "rehabbed" or flow matched. I wouldn't think you'd have to go as far as buying a new set, unless you're doing some major mods or have money to burn...

You'll probably get them going quicker if you "pulse" the 12 volts off and on, by removing and reapplying one of the wires. Also, at the same time you're doing that, have someone tap the side of the injector with a screwdriver handle or similar. That should get you going quicker. Sometimes just soaking won't do it.

I have a variable rate injector pulser here that I just plug onto the injector and turn it on. On the tough ones I just tap the injector a few times with the pulser turned on, and that usually brings right to life!

well I tried the tapping and cycling the power on and off with no luck. I sent them out to be cleaned and rehabed on a flow bench. I'll post results when I get tnem back. Thanks for the suggestions, they really helped me narow down the problem.

Well of the 8 injectors I sen out, 2 were completely dead, 2 wouldn't flow right even after cleaning and the other 4 cleaned up fine. 4 new delco inejctors later, it runs!!! Too bad it's raining here... gotta wait until tomorrow for the test drive. Thanks again for all the replies.

Colin

Colin, I am having the same trouble.. I am trying to crank it over for the first time. I have checked all my injectors and they all click. I had my wiring done in Whittier, Ca by dynotech. I can smell gas but no spark. Did you trouble shoot any other problems before moving to the injectors?? Anyone with Help??

77vette,

Luckily I didn't have to try anything else, but if the injectors didn't do the trick, I would try the following:

First, did you bypass VATS on the computer?

Have you pulled your plugs? are they fouled? Can you smell like gas? Can you try cranking it while grounding a plug outside the engine and check for spark?

If that doesn't work, try finding a scan tool to search for DTCs and see if that helps. Maybe someone with more experience can add something more helpful. Did you consult with the shop that did the harness?