Plenum pull scope creep - ZR-1 Net Registry Forums

evl_twn · 07-09-2022

I've got a 94 with just over 40k miles on it, had a no start happen for the first time last week so I ordered a new (I'm guessing reman) AC Delco starter. It showed up today, waiting on Jerry to get back to the shop before ordering the plenum gaskets.

Here's the question/dilemma: I haven't had the plenum off this engine since I bought the car back in 2006, and that was mostly just to tidy up a few things and remove the "power plates". Not sure if those really add any performance or not, but they were installed with no gaskets so off they came and gaskets went back in place. I still have them but I doubt I'll put them back on.

What else would be prudent to take care of while the plenum is off? I've been scouring the forum and I think it's time for new plugs/wires anyway, probably get the IT20TT plugs and a new set of wires as well since they're now over 28 years old. Looks like AC Delco wires are still available, but I've also seen a set from NGK that look decent. Blue in color, but that's not a big turnoff for me (car is yellow so it's not like the plug wires match anything anyway

) Should I plan on replacing the coils as well? I'll probably keep the original wires since they still work and still have the Corvette/LT-5 markings.

I've seen a lot of posts recommending injector replacement but that's mostly for the early years? The car seems to run fine.

I found Roadster's thread that started with throttle body removal and expanded from there, saw his post about the 90 degree 1/4" rubber fittings so I'll get a set of those before the plenum pull too "just in case". Would it be a good idea to replace the throttle body and air horn gaskets, or just leave them alone? Roadster's thread has me convinced to NOT clean the throttle body and risk issues with the DAG.

Planning on replacing coolant anyway, so that's one more job to do at the same time. Would you recommend the throttle body bypass line from Marc? I already have the metal hoops from Marc for the intake boot.

Thanks for any advice, I'm still in planning stage now so there's a bit of time if I need to get other parts coming. Anything else I'm missing?

Thanks!

07-09-2022	#1
evl_twn Join Date: Jul 2006 Location: Illinois Posts: 116	Plenum pull scope creep I've got a 94 with just over 40k miles on it, had a no start happen for the first time last week so I ordered a new (I'm guessing reman) AC Delco starter. It showed up today, waiting on Jerry to get back to the shop before ordering the plenum gaskets. Here's the question/dilemma: I haven't had the plenum off this engine since I bought the car back in 2006, and that was mostly just to tidy up a few things and remove the "power plates". Not sure if those really add any performance or not, but they were installed with no gaskets so off they came and gaskets went back in place. I still have them but I doubt I'll put them back on. What else would be prudent to take care of while the plenum is off? I've been scouring the forum and I think it's time for new plugs/wires anyway, probably get the IT20TT plugs and a new set of wires as well since they're now over 28 years old. Looks like AC Delco wires are still available, but I've also seen a set from NGK that look decent. Blue in color, but that's not a big turnoff for me (car is yellow so it's not like the plug wires match anything anyway ) Should I plan on replacing the coils as well? I'll probably keep the original wires since they still work and still have the Corvette/LT-5 markings. I've seen a lot of posts recommending injector replacement but that's mostly for the early years? The car seems to run fine. I found Roadster's thread that started with throttle body removal and expanded from there, saw his post about the 90 degree 1/4" rubber fittings so I'll get a set of those before the plenum pull too "just in case". Would it be a good idea to replace the throttle body and air horn gaskets, or just leave them alone? Roadster's thread has me convinced to NOT clean the throttle body and risk issues with the DAG. Planning on replacing coolant anyway, so that's one more job to do at the same time. Would you recommend the throttle body bypass line from Marc? I already have the metal hoops from Marc for the intake boot. Thanks for any advice, I'm still in planning stage now so there's a bit of time if I need to get other parts coming. Anything else I'm missing? Thanks!