Working on little things, may have some questions soon

[tiegsd]

Lots of good info in here. Appreciate the effort to document, need to do some of this stuff myself in near future.

[1991 Corvette ZR-1]

Originally Posted by tiegsd

Lots of good info in here. Appreciate the effort to document, need to do some of this stuff myself in near future.

Glad I can contribute in someway. I will also add the next time anyone is in the valley to take a look at the alternator plug. Mine crumbled to pieces when I removed it from the alternator to upgrade to the 200 amp power master. It gave 31 years of service and many heat cycles in 94K miles. The replacement pigtail can be had from various sources but I got mine from Autozone. It is Duralast #237. 14 bucks I believe. I have terminal pick tools, so I removed the wires it came with.

Then I surrounded what was left of the old rotted plug in a shop towel and with a pair of channel locks, I gently cracked it like a walnut. All original terminals intact unharmed. After that it was just a matter of gently plugging in the original terminated wires into the new plug. No splicing required. A few pics of that and where my lines ended up once the radiator shroud was back on. Waiting to test drive it to give the loctite 565 close to 24 hours to cure on the oil filter housing fittings.

Also, because I eliminated the secondaries and all the associated hard lines, no more vacuum line on the driver side of plenum. I just used a nipple cap to seal it.

[Matt B]

Great information, thanks for your efforts. This threat could be linked into our knowledge database, no?

Only I always find it sad when Secondaries are eliminated. Though I fully understand the motivation (and there is plenty) it's something only our ZR-1 have. So it's eliminating are piece of uniqueness and coolness.
Personally I even asked Marc to calibrate my chip in a way that low power mode remains standard at start up so I can/have to use that ultra cool power key to unlock her horses [emoji3]
But again, I understand there are good reasons to pull them.

Question: from your recent experience would you say that removing the whole oil filter assembly, cleaning and resealing it can be preferred over only replacing the sensor without pulling the while unit?

[1991 Corvette ZR-1]

Originally Posted by Matt B

Great information, thanks for your efforts. This threat could be linked into our knowledge database, no?

Only I always find it sad when Secondaries are eliminated. Though I fully understand the motivation (and there is plenty) it's something only our ZR-1 have. So it's eliminating are piece of uniqueness and coolness.
Personally I even asked Marc to calibrate my chip in a way that low power mode remains standard at start up so I can/have to use that ultra cool power key to unlock her horses [emoji3]
But again, I understand there are good reasons to pull them.

Question: from your recent experience would you say that removing the whole oil filter assembly, cleaning and resealing it can be preferred over only replacing the sensor without pulling the while unit?

I agree on the secondary operation. I enjoy it as well and I get a kick out of the noise the actuators make when you release vacuum and all the butterflies snap back shut. A few things made me eliminate them, lack of readily available repro actuators and putting eyes on the valves after the butterflies were removed. They were rough! And this is a higher mileage car and definitely driven by the previous four owners.

The method I chose was to leave the throttle shafts and bearings in place. Marc provided small brackets to keep all the shafts in the open position. So technically, it would be easy to convert back to the butterfly setup if desired. But I agree 100 percent with you, if it were feasible to keep the dual performance mode intact I definitely would.

On the oil filter housing, if it is your forever car, I say go for removing and restoring. Jerry?s has the replacement gasket as well as all sensors. I went with a 93-95 oil temp gauge sensor. So I removed the screw in bushing and threaded in the larger late model sensor directly into the housing. It ACTUALLY reads oil temp now on the gauge I can?t believe it. Old sensor after a two hour drive would barely be off the peg. I have heard that it is common for the low reading on the gauge, but I took a chance on a new sensor and glad I did!

I was going for a mostly complete refresh. I wanted to pull the housing because it was filthy and I did not want to torture myself trying to finesse a custom cut socket down there to remove the oil temp sensor. Also replaced the low oil PSI switch while I had it off. I even sourced the temperature element if I decided to crack the housing open but decided to hold off. If I need to in the future it appears to be accessible from the front while still mounted on engine.

The big catch is you have to drain coolant and remove the water pump hose to get access to one of the three bolts mounting the housing to the block. Attached a few pics of the temp element used inside the housing. This same bag and part numbers have appeared on eBay by different sellers for roughly $500. I believe I got it for $20 but do not recall the site. I have had it in the parts pile for a year or more.

[1991 Corvette ZR-1]

Moved onto something more fun I guess you could say. I cannot take credit for discovering these as it was ZuggZR1 who referenced them in a headlight upgrade thread. So figured I would give it a try. Weight difference also shown between Wagner glass bulb and the LED. Also picked up some load resistors to pair with the LED headlights. They get very hot from what I have read, so mounting them to something metal near the lights will be preferred.

Good news is the lights came with an extension piece that helps out. I want to try my hand at NOT hacking up the factory wiring, so that this is reversible if desired.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1


https://www.superbrightleds.com/more...lbs/2179/5079/

[1991 Corvette ZR-1]

Well I paused the headlight switch for the moment. Something wonderful decided to rear it?s ugly head. So did a couple of little drives post putting everything back together and 25 minutes into the drives, I am smelling gas. I pull over and check the cap and sure enough it?s venting pressure. I slowly undo it and get the classic outward blast of pressure.

I definitely plugged in the fuel vapor solenoid during reassembly and there are no trouble codes. I can blow through the vapor line unplugged from the passenger side connection and can pass air all the way out the hard line out back unplugged from the canister. So I took apart the rear wheel well housing and pulled the canister and check valve. I applied vacuum to the check valve and no matter how hard I try to push air through, barely anything comes out the other end. I found a replacement Duralast part PV111. Says on the Autozone website it does not fit, took my factory valve to the store and it is a carbon copy. Minimal vacuum required to actuate the diaphragm.

https://www.autozone.com/emission-co...v111/68757_0_0

Also ordered a new charcoal canister. I am already in there and the one on there now has been in place going on 32 years. Part number VC120

https://www.autozone.com/emission-co...v111/68757_0_0

Going to pick up the canister later today as the new check valve was put on last night. To make sure I am not crazy, I applied vacuum to the new valve and was able to blow air through it no problem. They also have the purge solenoid and you guessed it, I may be ordering one of those as well. Because I will go through this and my luck it will end up being a cooked purge solenoid. But wouldn?t a faulty solenoid throw a code? I guess if it?s energized but clogged, the ECM will not recognize an issue. I may have to go back under the plenum.

https://www.autozone.com/emission-co...v118/45380_0_0

[1991 Corvette ZR-1]

I have not updated this in a while, but I figured I would provide one. Combination of a new check valve, vapor canister and vapor solenoid under plenum did the trick. No more fuel smell and yep, I pulled the plenum again just to switch out the old solenoid with a new unit. The old unit worked fine after applying voltage and blowing air through the tubes, but if I went through the trouble of pulling the plenum, I was going to replace the old part anyway. When Pete did my top end porting, he plugged the TB coolant passages in the injector housings and I have to say that one update made a WORLD of difference for working on the Z.

I ended up saving the headlight wiring and not having to splice anything. The only wiring that got modified were the adapters that came with the resistors for the headlights. Everything is reversible on the original factory wiring. My motors also ran about ten seconds after opening or closing. So I rebuilt the motors while in there.