Maintenance on my '94 z28 pic heavy

[Mrmaroon]

I was checking my connectors and air intake for leaks. My optic connector wasn't fully seated. When I checked my coil pigtail I noticed this....


I don't remember the colors on the wires. I didn't see a 4th wire or a pin so I don't think it's missing. Every picture I've seen of this connector in a car has 4 wires tho. The Shoebox site shows 4 wires in the diagram. This is a 94 M6.



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[Injuneer]

Shoebox's 94/95 wiring diagram shows only 3 wires.

no wire on pin A on the black connector (actually, no pin)

pink wire to pin B on the black connector

white/black to pin A on the gray connector

pink/black to pin B on the gray connector

[Mrmaroon]

Shoebox's 94/95 wiring diagram shows only 3 wires.

no wire on pin A on the black connector (actually, no pin)

pink wire to pin B on the black connector

white/black to pin A on the gray connector

pink/black to pin B on the gray connector

Crap you're right. I was looking at the ICM like a dumbass

[Mrmaroon]

I've definitely got a Vac leak somewhere on the passenger side. I think it may be the AIR or EVAP who knows. I have a propane torch to try later.

For record keeping, this is EEhack analysis with every datalog I have added in. Including a shot of the o2 sensors so I can see if my other new one improves the right side or not. Its handy looking back at things from last year on here.

AllLogBeforeRepair.png

This is my overall plan for the car in the next few weeks.

• Check all wiring for ignition with a multi.
• Fix vac leaks.
• Hang fuel rails and check for leaks. KOEO 42 PSI
• Replace fuel filter after run of bad fuel.
• Install new torque arm bushing (it's slapping when I let off gas).
• New right 02. The left was replaced last year. Both ACdelco (Denso type).
• Clean and oil air cleaner.
• New intake temp sensor/maybe coolant temp sensor.
• Install new WP and remove old opti for testing.
• If old opti looks good its going back in. If not, I will try the assault racing opti.
• Redo my intake manifold seals. I might put in new lifters so I don't have to undo it again until cam.
• Check oil pump gear.
• Check all rockers and pushrods.
• Install new headers and Y (not ordered yet).
• Put in new motor mount bushings.
• Changing all wires with MSD and all plugs with NGK IX55s while headers are off. Making sure they are on perfect
• Making a new ALDL cable with 232 FTDI
• Might do some motor paint. Hard to beat @Dan pink pony motor.

This should keep me busy for a while. Luckily I've got a heated garage/shop and a forklift. No car lift, only ramps and jack stands. If I should check something that isn't listed while the car is unbuttoned please let me know.

[Injuneer]

I see two color coded grids with red in the upper left corner. Is one Bank 1, and the other Bank 2? They appear to be LTFT's for various combos of RPM and MAP (engine load), roughly correlating to the 16 operating cells. Is all that correct?

If that's correct, it's running rich at idle/low load both Banks, and one side (Bank 2) leans out at the top end. At idle, it's pulling ~6% fuel out. A vacuum leak will be more obvious at idle/low load, where MAP is high and the vacuum leak represents a sizable percentage of the total air flow. The fact that it's puling fuel out at idle, the MAP is actually relatively low (indicating good engine vacuum) would not seem to indicate a vacuum leak. MAF flow is where it should be.

How did you determine that you have a vacuum leak on the passenger side? Again, not sure what those two grids represent, since they are not labeled as to what differentiates one from the other.

[Mrmaroon]

@Injuneer I I should have labeled it - the grid on the left was L/R average BLM+INT average together. The right side is the L/R avg of just BLMs. This is the data of all my logs.

I did another datalog last night of the car cold (32F) start to hot with maybe 6 hot cycle at idle. The BLMs were closer then dropped to 111L 118R with INTs steady at 125 both sides. This was after idling for 20-30min. It didn't look like it was going to change much from there.

The popping and shaking really became noticeable at 800 seconds after starting. This was before closed loop or BLM mode was activated. It's always worse the hotter the car is.

I can't find many reasons why a car shows a rich/low BLM besides leaking injectors. I'm not sure if my car is really rich at idle or the pcm just thinks it is.


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[Injuneer]

If it's a L+R average, how did you reach the conclusion that the passenger bank has a vacuum link?

Why would you wait 800 seconds to activate closed loop? The typical transition is based on the programmed timer, which is 206-seconds. Or are you saying the PCM had not entered closed loop on it's own by 800-seconds? Why run in open loop with the engine fully warmed up?

I really think you would be far better with a continuous log, done with Datamaster or Scan9495, showing the reading of every critical sensor and PCM parameter values at the rate of up to 9 frames per second. Then you could look at the area around 800 seconds, and see if you can find what values changed that may have caused, or indicated the cause or the popping and shaking. Maybe you can do that with eeHack, I just have not seen one from that system.

[Mrmaroon]

@Injuneer You were right on the vac leak Fred, it was my K&N filter making the noise - It had almost fallen off the tube. I hit the bugs out of it but didn't re-oil. The 800 seconds bad idle was in my mind. I forgot that I was watching my O2mv drop for a few minutes before I started the car . The heaters must run with the key in acc. You can view everything in EEhack like you can in scan9495. I took that picture to compare it after I do my exhaust/02 and opti.

Here is a shot of the pump my idle is getting worse.

My torque arm bushing is cut in half. I've got a new one of those too.

Edit: I may buy this http://www.opti-shield.com/opti-shie...tallation.html for my new water pump

[Injuneer]

The stock TA bushing is split in 1/2, with one half of the bushing riveted to each side of the clam shell housing. That's the way they made it.

Only some of the aftermarket replacements are one-piece, like the Energy Suspension poly.

[Mrmaroon]

That's good to know on the bushing. Ive been working on the front of the car. So far draining the rad and removing stuff. I found something crazy though. . . I went to unplug the bottom hose on the right looking from the front. Was expecting a shower of coolant, but only puffs of dust came out.

I knew my coolant level gauge was working right when it blinked some days. Glad I trusted my gut and left it plugged in. It didn't change this outcome though.

I bought a 94 service manual and ohm tested my coil. I got solid 8.4kohms on all 4 holes. The metal plug end was very white colored like lead oxide on a battery. Maybe from the dielectric grease


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