tommypenguin

Hey guys, I just got done rebuilding my 347 in 01 supercharged corvette. I installed a 2 bar map and switched to speed density tune, the tuner Nicd came over to my house to load a base tune and pointed out I have a miss and that my spark plug wires were touching the headers on cylinder 3 and 7. I’ve only put 10 miles on the car and have been troubleshooting a misfire on bank one. I replaced the spark plug wires with hinson and now no wire touches the cylinder.



I had the fuel injectors flow tested, replaced spark plugs and wires. Have used an infrared thermometer to scan each bank and cylinder 7 is the coldest by 75-100 degrees. Cylinder 3 previously read colder than the other cylinders prior to replacing plug wires now it is comparable to the others.



When looking at my log the bank 1 and bank 2 o2 sensor are stoich when starting the car and then diverge and bank 2 goes super rich and and bank 1 goes super lean. For kicks I’m planning on swapping all fuel injectors, coil packs and plugs to the other bank to rule these out. Any one have a suggestion on what could be the culprit beyond what I’m attempting.



I used new intake manifold gaskets on my fast 92. I replaced the crank position sensor while rebuilding the motor. I ripped off the g107 ground on the back of the driver side head and had to solder in a new ring terminal to use for that. Any ideas are welcome, thanks.

mOtOrHeAd MiKe

iTrader: (8)

Try switching the O2 leads from bank to bank.

tommypenguin

I have long tube headers and don't think the harness will be able to reach. May be moot after my findings last night.

I swapped all the plugs between banks and noticed on cylinder 7 the plug looked brand new and was white as snow. This aligns with what my laser thermometer was showing that cylinder was lean.

So I also went to swap injectors between rails and ended up pinching and damaging one of the injector to rail o rings while doing the swap. This brought back my memory of installing my injectors after getting them flow tested. I dipped my finger in oil and lubricated the surface of each o ring for the injector before installing but recalled a couple of them were difficult to get on. After damaging my o ring last night it got me thinking there is a chance I may have pinched the o ring for cylinder 7 causing that cylinder to be lean. Need to find a part number for the o rings on my deka 107964. Reinstall and see how it goes.

If that doesn't fix my issue next up will be testing voltage on the injector harness plug for that cylinder and then checking coil pack harness as I have already swapped coil packs.

blackbyrd

iTrader: (14)

he means physically moving them I think, to see if the problem moves with the 02.

I had a similar issue with my 414 and it ended up being a blown o2 heater fuse in my case. cylinder 7 still being cold though is an issue that wouldnt be resolved by the 02.

have you checked the #7 injector to see if its actually putting out fuel. this is an easy spot check with a poor mans stethoscope. take a pry bar or flat head screwdriver place the blade end on the injector body and the handle to your ear. You should hear an audible tick with each pulse.

also you are thinking of it backwards if it reads lean bank1, the ecm will dose fuel and it ill continue to increase injector pulse until it goes rich trying to maintain stoich. reverse for bank 2 reading rich it should slow the injector pulse to lean it out. Now if number 7 isnt spraying but is sparking that would mimic lean. are you letting it idle enough to go into closed loop? The biggest issue I see is that the O2 readings arent switcing they should be bouncing back and forth once it gets into closed loop to maintain stoich. Also I only see injector pulse for bank 1 I would be curious to see what its doing. Id try checking your O2 heater fuses and make sure you are getting into closed loop. Just looked at your temps you didnt let it run long enough to get into closed loop ( engine needs to get to operating temp ) unless closed loop enable setting was changed by your tuner.

tommypenguin

I am not getting fuel from the injector at cylinder 7. I tested voltage on the pigtail that connects to the fuel injector with the key in the on position and got zero volts versus 14.3 on the rest of the injector pig tails. Saw g107 is the ground for the injectors on the passenger side of the block. Fuse 18 and 22 are good for injectors. Should I begin a quest looking for a damaged wire or other troubleshooting I should do first?

PS got cel p0200 injector circuit cel

blackbyrd

iTrader: (14)

id check the grounds on the back side of the heads make sure there are no exposed wires. Might be an easy one, other than Identifying the actul wire, but id start at the head grounds.

tommypenguin

Will do, will cut off the extended wire I used for the g107 back of head grounds and use a thicker good quality copper speaker wire I have this time. Will be able to rule out the ground. Attaching the wiring schematics for the injectors on the corvette c5. What’s odd is it seems like if it were the g107 pcm ground it would only present itself with the and not while the ignition is on?



Planning on doing the ground, checking voltage on the cylinder 7 injector pigtail. If the injector pigtail is still showing zero volts will use a wire probe right before the pigtail and rule out it’s a bad connection between wire and pigtail and continue down the rabbit hole. Hope it doesn’t get to that point.

tommypenguin

Ended up being a torn wire an inch after the pin on the connector.

G Atsma

So all is good??

blackbyrd

iTrader: (14)

HEY! good find she running better now?

tommypenguin

Got the new ev1 connector and soldered in. Car is stoich with afr at idle. Will road test tonight.