Following up on this thread:
http://forums.corvetteforum.com/show....php?t=1451709

I pulled the plenum and found a small amount of fuel inside. That leads me to believe that the FPR is bad along with any of the injectors that might be leaking (I didn't get the fuel rail pulled as I was threatened with divorce at that point!).

 

Hey Silver...sorry to hear that you are having issues. I had a similar thing happen to me after I built my engine with cleaned and checked injectors. Turns out that from the time I picked up the injectors to when I fitted them, one of them crapped out.(Or wasn't diagnosed as faulty!)
I found this out the hard way...after what seemed like real bad flooding occurred on start-up
I checked fuel press. and it was fine with ig. "on", but quickly dropped off...like in 5-10secs to almost zero..
So I pulled all sp. plugs and cranked the motor. Raw fuel just p...ed out of no. 8 cyl. By this time the crankcase was holding heaps of petrol, so I drained the oil, fitted a new filter with oil, changed out the badly leaking injector, and it was all fine.
Just one thing...be careful. Like someone said earlier, you need the ig. wire connected in the distr. for the injectors to pulse. With sp. plugs removed MAKE SURE you keep the plug wires away from ground and the sp. plug holes....My car caught on fire when cranking the eng. to clear out the fuel after a hi-tension lead fell onto the ex. manifold! Luckily I had a fire extinguisher handy and quickly worked out how to use it!!
Hope this helps...but I have a feeling you will need to pull the rail and injectors...

 

I've got the rail unbolted and ready to pull.....the other half just happened home at that point and everything was put on hold. I ordered a new AFPR just in case I need it.

I'm going to pressurize the rail first without hooking up the injector harness just to see if one of the injectors is leaking out. Then I'll hook up everything to get them to pulse. Thanks for the reminder; I have the dist. unplugged at the moment, and I'm not sure if I would've remembered to plug it back in order to get the injectors to pulse.

I probably should pick up a chemical extinguisher at this point. Hopefully I will never have the need to use it!

 

Evap. system could put fuel in the plenum. To check if the FPR is leaking, look in its vacuum hose.

 

I know what you mean about the other half. I have to plan a day weeks in advance to work on my vettes. They are not the DD or primary vehicle so...last on the list (as far as the wife is concerned).

You can pull the fuel rail up (injectors attatched) just enough to see the bottom of them. Then connect the battery and turn (have someone turn) the key to the on position and visualy check for leaks.

 

I'll check the check valves on the vacuum lines to make sure no pressure is flowing out of the engine.

 

I'd go with the Halon one if I were you, that way you don't have to tear the engine down to a short block to get all the chemical residue out if it happened to be running when it caught fire! Learned this one the hard way!!!!!

 

That's a good idea!!

 

Well, I pulled the fuel rail and leak checked without the harnes--no problems with the injectors, not a drop anywhere. So I think the drop here is do to a bad FPR. But, once again, when I plugged in the harnesses and pressurized the rail, the injectors dumped the whole fuel load and psi went to 0 instantly. I called Summit (where I bought the injectors), and I can only return the entire set of injectors for replacement (they don't sell them individually), so I guess that's what I'll do. I am going to re-install the factory prom just to see if it's something programmed in the pulse width from the new prom before I package them up.

I also found a slight residue in the vacuum line from the pcv valve. I have the pcv valve, the charcoal cannister, and the intake tee'd together, but I only had a check valve before the pcv valve meaning the cannister was receiving positive psi when the engine was under boost. Not sure if this would have damaged anything or contributed to the hydro-lock or not.

 

If your injectors held up fine with pressure and dumped when the harness was plugged in, ground short in harness comes to mind.
Did you crank it, or was it just plugged in.

 

It was just plugged in. I hadn't removed the runners yet, so the entire rail wasn't visible enough for me to crank it and get an unobstructed view (and I really didn't want to stand that close while the wifey spewed fuel everywhere turning her over and plug wires dangling close by). I'll pull the runners tonight (if I get time), since I'll have to completely remove the rail anyway.

I checked over the harness briefly, I didn't see anywhere that it was grounded or rubbing. It's still covered in all the original electrical tape and plastice protectors. Any other way to check for a grounded harness?

 

Shane,
I have been watching your situation for the last two weeks.

Questions/thoughts that you may want to consider are:
- How much fuel psi were you running at WOT (max boost)?
- Were you (are you) running an FMU?
- Would it be possible that you might have "pimged" the new injector set? This is usually caused by too much fuel psi. I have found stock injectors failing at 65-70 psi, but aftermarkets will usually hold a bit past 80 psi.
- Do you still have your stock injectors to put in the car to test the injector theory? Does someone close by have a spare set of injectors for testing? You don't live close to me, otherwise I have quite a few sets.
- I know that occasionally wiring does go bad, I find this to be the exception not the norm. Typically blame falls squarely on our shoulders for something that we did.
- One way to alleviate the potential for fire is to remove the power lead from the distributor. This will allow no spark from the coil.

The above list represents some things to consider.
Aaron

 

Put your DVM to read ohms and place one lead to ground and the other lead to ground side of injector harness. If there is a short in the ground part of harness you will see continuity on the DVM. Do the same with key on to check if ECM is supplying ground while engine is not running.

 

Hey Aaron,

These injectors have not seen above 42 psi (well, at idle anyway, my pressure gauge is rail mounted and I never went full throttle since my intercooler isn't wired yet). My standard idle psi is set @ 39.

I am not running an FMU; Greg suggested the 42's and a 225 lph pump instead of the FMU.

I just sold my factory injectors. I have a set of used pink top Accels, but I've never tried them; guess it couldn't hurt.

If I remove the Bat line to the distributor, will the injectors still fire? (I thought someone suggested that the dist. needed power as the injectors derived some type of pulse or power from the harness)

 

I'll give that a shot, thanks Agent.

 

I checked the injectors with the key in the on position. (Here's how little I know about this electrical stuff...) I placed the black arm of the DVM to the ground side of an injector clip, and got a reading of -1, on the right side, I got a reading of 647-648.

Did I do this right? If so, what does this mean?

 

You will need to set it to ohms. When you ohm the injectors one lead goes on one terminal and the other goes on the other terminal. It will give you a reading of a correct injector resisitance of 16.0 ohms. If any are way off from this number you have a bad injector as far as resistance and not leakiness.

 

I Ohm'd the injectors, they all were 16. This time I was checking the harness to see if it was grounded out and letting the injectors fire constantly. I'm just not sure what my results mean.

 

I just used a test light on the injector harness. If the test light lights up when the engine is not being cranked then there is a problem. When cranking you should get a light or a blinking light. A noid light is used for this test also.