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32valvZ
11-29-2019, 12:27 PM
If you were going to pull the plenum, would you replace the coils while it was apart?

One gentleman on this site has a stock set with 4800 miles on them, very reasonable.... & I was thinking that would be a decent replacement to my 35000 mile set.

I know that Accel makes them, but I feel stock units are probably as good if not better?

What would your choice be?

Ccmano
11-29-2019, 12:38 PM
Unless the car is an NCRS car I always recommend replacing the coils and wires when doing a first plenum pull or if they have never been done. Aside from mileage you have the issue of age. Our cars are 25-30 yrs old. Who knows how many start/stop cycles it gone through even on a low mile car. Why take the chance. AC Delco coils are still available and a new set of AC Delco replacement wires can be found as well, largely on ebay running about $75-$100 set. If you drive the car regularly it’s a minor investment in reliability.
H
:cheers:

A26B
11-29-2019, 02:32 PM
If you decide to stay with ACDelco coils
https://www.jerrysgaskets.com/coil-ignition-new-acdelco-90-95-6b3/

These are made by the same manufacturer that made the original plug wires for the LT5. Same color & sheen, just without the Corvette LT5 silk screened lettering.
https://www.jerrysgaskets.com/wire-set-spark-plug-90-95-9b2/

and plenum gaskets which you will need to replace coils & wires.
https://www.jerrysgaskets.com/gasket-set-intake-plenum-1-32-90-95-7-5d2/

tgonyaw
11-29-2019, 02:33 PM
When I purchased mine in July 2018 it needed injectors and a starter. I didn't want to do the job 2 or 3 times so Dempsy at Evolution in Fredricksburg replaced coils,spark plug wires,spark plugs, injectors,starter,alternator,PCV hose assembly,deleted secondary throttles,deleted throttle body coolant,ported intake.engine tune,powder coated intake/valve covers along with replacing all fluids in car. This car had 74,000 miles and was all stock in good condition. I have since added about 3500 miles and a new Corsa cat back exhaust. The car has been totally trouble free and is a very "happy car" going down the road.
I was worried about the almost 30 rear old maintenance parts and decided to do it all a once so I would know what was in the car. The only judging this car will see is cars and coffee along with the 10 foot,10 mile an hour drive thru! Hope this helps with the decision.

Paul Workman
11-29-2019, 04:55 PM
If you were going to pull the plenum, would you replace the coils while it was apart?

One gentleman on this site has a stock set with 4800 miles on them, very reasonable.... & I was thinking that would be a decent replacement to my 35000 mile set.

I know that Accel makes them, but I feel stock units are probably as good if not better?

What would your choice be?

Preventive maintenance: Age, and heat cycles plays a factor in the life of coils (of all sorts).

FWIW, one of my stock coils failed on the HI voltage side @ 42k. miles. I swapped them out for new AC Delcos & new plug wires, sans the silk screening: now @ 73k w/ no issues.

+2 for replacing them now. But, as long as the coils have continuity, (primary & secondary sides) and neither is shorted to ground and the car ran fine w/ the old coils, maybe keep one "in case"...as a spare.

XfireZ51
11-29-2019, 09:14 PM
When I pulled the plenum for the first time, I swapped coils and injectors. I could also suggest freshening up the starter motor contacts.

32valvZ
11-30-2019, 01:00 AM
Ok, guess I should clear a few things up. The plenum was pulled a couple years back by the previous owner. New starter was installed, new wires and the coolant passages were blocked off to the intake. He did a good job on it, but I know he didnt replace the coils.....

I'm pulling the plenum only to ship out the injector housings and intake to Pete for a port job. Yea, I decided to leave it to a pro....

:cheers:

Paul Workman
11-30-2019, 09:59 AM
Ok, guess I should clear a few things up. The plenum was pulled a couple years back by the previous owner. New starter was installed, new wires and the coolant passages were blocked off to the intake. He did a good job on it, but I know he didnt replace the coils.....

I'm pulling the plenum only to ship out the injector housings and intake to Pete for a port job. Yea, I decided to leave it to a pro....

:cheers:

You'll love the improvement. Lotus really choked the potential of the LT5 with their initial porting scheme. Even with the very conservative "kiss" to the top end in the gen II (405 HP), no question they still left a lot of performance on the table. No question. AND, the best thing is, you'll not loose any mid-range torque, fuel mileage, or drivabilty: what's not to like!?

XfireZ51
11-30-2019, 10:05 AM
Ok, guess I should clear a few things up. The plenum was pulled a couple years back by the previous owner. New starter was installed, new wires and the coolant passages were blocked off to the intake. He did a good job on it, but I know he didnt replace the coils.....

I'm pulling the plenum only to ship out the injector housings and intake to Pete for a port job. Yea, I decided to leave it to a pro....

:cheers:

Good move.

Z51JEFF
11-30-2019, 05:56 PM
Years ago when I replaced the injectors in my 91 I also replaced the coils with new AC DELCO coils only to have one of them fail with very little miles. I pulled the plenum and replaced the coils with a set of Accel coils.