luvmy88

I have a 1988 convert. with 96K miles all original.
A while back I was getting the SES light and codes 42 & 43. After posting here I have sense replaced the fuel injectors with Bosch III. While doing that I chased down a coolant leak and replaced the water pump and Knock sensor. So all new seals and gaskets in water pump, intake man, risers & fuel rail, new EGR valve and EGR solenoid, new plugs and wires and coil. I pulled the ECM and cleaned connections. I was also experiencing spark plug wire arching (still am).
All these changes eliminated the coolant leak and the code 42 & 43.
PROBLEM... now I'm getting a code 44 (Lean condition)
With battery unhooked and codes cleared, car starts and runs, idles. I take it out and drive about 10 miles before the SES light comes on.
Any thoughts?

Whaleman

http://www.misterfixit.com/code44.htm

luvmy88

Test description:

1.) Code 44 is set when the O2 sensor signal voltage remains below .3 volts for 50 seconds or more and the system is operating in "closed loop".

Diagnostic aides:

The code 44 for lean exhaust is most likely caused by one or more of the following:

1.) O2 sensor wire - Sensor pigtail may be mispositioned and contacting the exhaust manifold.

Wire appears to be routed fine.

2.) Check for an intermittent ground wire between connector and sensor.
I'm not really sure how to check that? Can someone explain better?

3.) Poor ECM to engine block ground.

Were is the ECM to engine ground? This could also explain my spark plug wire arching, couldn't it?

4.) MAF Sensor - A MAF sensor that causes the ECM to sense a lower than normal airflow will cause the system to go lean. Disconnect the MAF sensor. If the lean condition is gone then replace the MAF sensor.

Can I disconnect the MAS connector and drfive the car for about 10 miles without damaging anything?

5.) Vacuum leaks can cause a lean condition and/or possibly a high idle. Check for cracked hoses a bad gasket or a faulty EGR or PCV Valve.

I replaced the EGR and gasket with new and also a new PCV valve

6.) fuel pressure - system will go lean, if pressure is too low. It may be necessary to monitor fuel pressure while driving the car at various road speeds and/or loads to confirm.

Fuel injectors are new, pressure at idle is 38/40, and at quick rev jumps to 50/52. Not sure about at highway speed. I will have to check if I get a chance. It's beginning to snow here and this may have to wait until spring.

7.) Clogged injector or lean injector - perform an injector balance test..

As I said, injectors are new (Bosch III) I don't have the equipment to test for balance.

PatternDayTrader

You have to fix this first then evaluate the fuel trim lean code. A dead cylinder will pump o2 into the exhaust, you have a fuel trim lean code. Fix your plug wire first.

ctmccloskey

I agree with the above posting, replace your spark plug wires and try from there.

I saw that in your initial posting that you replaced the plugs and the wires already. The "new" Spark plug wires are arcing again? Where are they arcing? And of course, What Brand were the "new" wires?

I have been using MSD spark Plug Wires and I have never seen one arc yet.

After reading the article by "MrFixIt" I would be suspicious of your existing O2 sensor. They are not too expensive so you might install a new one after resolving the wire arcing issue.

O2 sensors need to be replaced every 50,000 miles or so, I do mine more often to keep the car running the best it can.

Good Luck and I hope that it gets resolved quickly so you can "enjoy" your Corvette!

luvmy88

The new wires are MSD 8.5mm Super Conductors. and they are arching multiple places, at plugs and along the wires on both sides of the engine.

Whaleman

Spend a few minutes googleing "Spark plug wire arching". The most mentioned is bad grounds especially from the coil to the block. I am not knowledgeable enough to tell you where to look on your car. There are multiple stories of replacing the wires 2-3 or 4 times before they found the bad ground. If it was me I would run a temporary ground wire from the negative battery to a clean bolt on the block and then to the negative terminal on the coil and see if this helps. Dan

luvmy88

Good idea, thanks... but couldn't I go directly from neg battery terminal to neg terminal on coil?

Whaleman

I will let a more experienced expert respond. Remember we don't know if the bad ground is the coil to block or battery to block. I am really way over my level of knowledge here so I hope a pro jumps in. All I did find in my google search attempting to help you was that wild spark plug arching was sometimes related to a bad ground. Dan

Whaleman

Remember the spark plug is in the block. If the block is not grounded correctly the plug will not work.

PatternDayTrader

Typically if spark is arcing from the plug wire to ground somewhere, then the plug wire is bad. Generally if this is happening then you have a misfire or dead cylinder. Under unusual circumstances you can have voltage leaks from a plug wire, and the plug still fires, and the engine runs right although this usually only happens if the plug wires are wet.

luvmy88

I don't think my pressure is low, it shows 38/40 at idle which I think is normal. I also have an adjustable fuel pressure regulator, which would allow me to dial it up a little if need be.

luvmy88

Latest check... I check the fuel injector wire connectors and they are NOT providing 12 volts to the injectors. Drivers side showed 11.22 and pass side was 11.27. I did notice something puzzling... I get the same reading on both pins in the same connector??? Shouldn't one side of the connector show "0" volts?

Battery check 12.14 v
Does the lower volts at the connectors show that there is a ground problem? Does anyone no where the ground is for the fuel inj harness?

luvmy88

Update... I ran a separate ground wire from Neg Bat terminal to the coil ground. Then checked the volts at the fuel injectors again and they checked same as battery 12.14v

After dark, I did a visual check of the spark plug wires and they are STILL arching... both sides, but worse on the pass side... WTF?

Whaleman

Try the separate ground to the block like I suggested a while ago. Better yet clean the ground from the battery to the block. Also check and clean the battery connections. You could still have a ground problem. New sets of plug wires don't all go bad at once when new. Did you by any chance use anti-sieze on the new plugs? I once saw this problem and the plugs were slathered with a type of anti sieze that was dilectric. For some reason the coil charge does not want to jump the plug gap. Electricity will ALWAYS take the easiest path to ground. it could be as stupid as a failed negative battery cable. Just last week I had to replace my positive battery cable. The side terminal had leaked acid and ate up the connection and wires inside the plastic end piece. It looked perfect and was junk. Remember I am not an expert, but if you took a jumper cable and hooked to the negative terminal of the battery and start the car. Take the other end over to the block and see if any sparks jump (or if wires quit arching). You should have none. Will take 5 minutes and will quiet me down about the grounds. Thanks Dan

PatternDayTrader

Is it misfiring when its doing the above ?

PatternDayTrader

Need wiring schematic. Maybe someone will post it.

luvmy88

I will try a separate wire to the block first and will also try the added jumper wire.. I'm up for anything.
As for clean grounds, I've cleaned two grounds near the Battery, and one that is on the block near the oil filter and also the ones near the front that are for the head lights. I have a schematic that shows there is an ECM ground on the pass side near the back of the engine that I can't see or find???
I DO have anti-seize on the spark plugs - very little and just on the threads, not slathered
Thanks for you input.

luvmy88

If it's mis-firing, it's not bad??? It seems to run alright, idles alright, but I must admit to not having a trained ear when it comes to it. Not really sure how it should sound?
BUT, sometimes when the electric fan kicks on (car still cold) the engine will noticeable stumble... and the SES light comes on

Whaleman

Again, you can check real quick with car jumper cables. One end to negative battery terminal and the other end to a good clean place on the block. 5 minutes tops. Good luck, I hope it fixes the arching then you will know the problem and we can go about finding where the bad ground is. Dan