C4 Ignition Tune Up

[@mcm95403]

Chris, The easy way to get the plugs out is to jack the car, remove the front tires, then remove those access panels over the upper control arms. Then you can reach right in and change the plugs in a couple of minutes.

[@dukeman7595]

That's a fact, appears you have done this before. Great advice.

[@NanceLvr]

This will save me alot of time! 😂 Inwould be struggling like him. Also, why are his new plugs shorter than the previous ones??

[@bohander]

Again ,thank you from Chris. B.R. Erland from Denmark.😊😅

[@ryanle1293]

I had an 87 being my first project car. I've never even touched an engine bay before. My friend who is not necessarily a mechanic but is infinitely more handy than me was helping me one day. I told him the ride was super bumpy, he thought the engine was running rough because of the spark plugs we later discovered it was from ten year old tires. Took the both of us four hours to change only the plugs lol but when we got them done the feeling was amazing

[@LEDlichtDesign]

Hello Chris. Your videos and your tips and information are just great. Calmly, objectively and well-foundedly presented, it is always a pleasure to listen to and watch them. Unfortunately, my English is not so good that I understand everything and can follow your words perfectly. But you get a thing or two and understand it. The red Corvette runs really fantastically well. I would be proud if my 1987 C4 convertible ran just as well. But slowly and step by step I'm trying to get there. Please keep it up.

[@SuperGerry2009]

Hello Chris I have full confidence in your next video footage The engine will definitely start after everything you've done, fingers crossed.

[@ba2724]

Ah, I see this vid was posted now but was actually was filmed before you got into the top end of the engine. Still happy to see new content.

[@colt5189]

That black rubber disc that goes under the coil, you are supposed rub a thin layer of dielectric grease on both sides before you drop it into the cap. I don't know if there will be any problems without it, but I believe it's supposed to be a moisture barrier and to keep the spark from jumping out and going to places it isn't supposed to go. Also, whenever I unplug connectors like those on that cap for the battery, etc. I usually get a can of electrical cleaner and put the red straw on the nozzle and then spray down the metal tabs on those connectors. I don't know if that cleaner does anything, but I figure it would be good to at least blast out any crud or dust that might be in there. When I do wires, I have them all marked and I pull them all at the same time. I then match them up to my new plug wire set. And then I start at the rear. I do the two rear on the driver side, and then I do the two rear on the passenger side. I then do the same for the front wires on both sides. and I do like you did by drawing out a diagram of how they go around the distributor cap. I usually use AC Delco on everything, but I go with an aftermarket distributor cap and rotor because I like using brass terminals instead of the aluminum like on AC Delco. I also use NGK spark plugs because their casings are plated so they don't rust unlike the regular copper AC Delco plugs. By looking at the AC Delco logo on your spark plugs, I'm betting they were from the factory as they have that old school AC Delco font. You can get new plastic clips that clip on to those metal brackets coming off of the sides of the valve cover area. I had to do that the first time I put in new plug wires ad those clips just kept breaking and falling apart when trying to reuse them. The last time I did cap/rotor, I went ahead and replaced the factory coil just as preventative maintenance as they were only like $30. I'm in the process of doing my cap/rotor and spark plugs again. I was going to get that WVE (A brand name I've never heard of before) from Rock Auto when I was going to place an order there, but they wanted an extra $10 shipping charge, and I instead got the BWD set that has brass contacts. Last time on plugs I went with NGK V series copper. But this time I decided to go for NGK G series platinum. Reason is those plugs are gapped at .035" from the factory which is what the book calls for and I decided to try out platinum as I've only ever used copper before. I did look at going with AC Delco Rapidfire plugs, though they gap theirs at .045" and AC-Delco says you are not supposed to change the gap on those. Though the factory book calls for .035" gap. And so doing online research, I've read a lot of debate on if you should leave it at .045" or try to regap it to .035". So after all that research, I decided on NGK G series platinum since they are gapped at .035 which is the same that the book calls for. Last time I went with Delphi Made in the USA plug wires. I'll probably do plug wires again some time down the road. I'll probably go with AC Delco and use the OEM version. As AC-Delco has two different plug wire sets for these cars. I don't know the difference though.

[@triple7441]

Este vato escribio un libro no manches

[@richarddobreny6664]

Amazing how what would have been considered a normal maintenance item turns out to be so challenging. These are great reference videos for and C4 owner. I hope that it’s a noticeably better running car after all that work!.

[@genemauguin2274]

To remove #2 plug. First remove upper wheelhouse panel (6 10mm) then a/c rear brace. Now use 12" 3/8 extension to reach plug. Distributor tuneup requires replacement of pigtail. GM recommends 60k replacement.

[@vladpootin5973]

Great and very helpful informative channel,

[@markcraig3702]

I will be doing this on my 90 C4 and can tell that it will be taking a while to get this completed/ LOL, Great Video Chris.

[@bohander]

Hi Chris. Again a very usefull video.Thank You. Erland from Denmark.😅😊

[@gizzmo5952]

The number 2 cylinder spark plug comes off easier with the center innerfender removed. I used Accel 8MM yellow wires. You cut to length and install the boot to the distributor. Plus I routed my wires differently. I bought a chevy emblem wire router made for the center style valve covers from Summit, which allows me to run my wires above the valve covers, and gives it a unique look. If I could send ya a picture you would see what I did to mine.

[@timothyodell5245]

I need to plan for some spring upgrade on my c4. I find your channel informative! Long time c4 owner and now a c5 owner but not really liking the c5 as much.

[@spenceair1972]

You have to take the wheel off to get to that plug. Same way on my dad’s 72 sting ray and my 78 trans am.

[@darrenbrown896]

Hey Chris...that trick to get scuff marks and stuff off the car with WD40 and Mr Clean worked AWESOME! Saved me a paint job!! :)

[@mycorvettelife]

👍

[@mjphoto45]

Did you gap the plugs?

[@MrNebRebew]

Do you remember what torque value you used on the spark plugs? My factory service manual which states aluminum heads is saying 22 foot pounds, but the Hanes service manual says 12 foot pounds for aluminum heads. Which one is correct?

[@GregorioLonewolf]

Hey Chris even stock exhaust manifold aren't easy to get the plugs out, especially on the passenger side. Now try doing this with shorty header's then long tube header's. I've done all 3 and found swivels and extensions & going thru the upper A-arm is beneficial. Great job in showing the stock configuration. Oh, a broken plug or 2 isn't uncommon, rather common I found.

[@ranbymonkeys2384]

You can do that without taking the tire off or jacking it up.

[@xXcashXx3]

I remember i went threw the fender on wheel well theres hole for a ratchet and a long extension and swivel socket to fit threw

[@dukeman7595]

That's the best and easiest way to remove #2 and #4 spark plugs.

[@colt5189]

@@dukeman7595 I too would use the fender well to get to #2 and #4. I believe I also had to remove that bar that goes to the A/C Compressor.

[@dukeman7595]

@@colt5189 Yes sir you did it right for sure.

[@jimharrow8104]

Very nice...

[@jeffshore2241]

I have a 1991 convertible corvette. The front passenger spark plug, I take part of the wheel well off. then a long extension and a swivel. I use a piece of rubber hose to the the plug threads started. Also, c4 custom tuned chip PCM of north carolina. They are awesome

[@milesbaskaran5196]

What company

[@jamesturley768]

That's the wrong plug for that car I made the same mistake you need to wash your Long reach for those aluminum heads

[@nashrambler5246]

Keep up the good content man!!! 😎

[@Rayzrs]

Not sure if you read these. since most are a year old. My C4 has an Accel Distributer. label on the underside of the hood has info regarding it. I should still be able to use a regular cap and rotor can I? I just wont be able to experience the thrill of Accel's component's if I do.

[@ramiram84]

@14:07that rockauto life

[@Nzchimeran]

Hiya, What DIY tuning software and OBD1 diagnostic tool would you recommend on a budget? Is there a way to get an OBD2 tool to read the OBD1 data?

[@gilbertorico-hb2xj]

Hi sir science u know those corvette very well can u telme if they have a crankshaftpositionsensor

[@RobertOShea-c6d]

I believe only on the 96 It's on the passenger side of the timing cover. I accessed the bolt from below with a wrench 8mm I think it was, then R and R from above. Mine was leaking oil all over the front of engine and opti spark. Just needed new o-ring.

[@ttspeedster8930]

😎💯🔥👍🏾…..hello Chris….what products numbers were those and where did you get the parts from, I am working on my C4 1987 Vette, thanks

[@Skizzags1974]

Chris, I’m sure you noticed the difference between the plugs you pulled out and the ones you installed. I too have a 86 I recently picked up and doing a good bit of work on. I did my plugs, wires and complete distributor and timing. From my understanding the L98 has 2 different heads (cast iron and aluminum). But from what I have found is that the corvette only talks of the cast iron - at least for the 1986. When I pulled out the old plus mine looked like yours with the washers. My new ones did not have washers which got me to looking into that difference further. The ones with the washers are for the aluminum head and they are actually longer than the tapered without washers. What about the 88?

[@mycorvettelife]

Interesting....I have no idea.

[@Skizzags1974]

Check out the pic you added to the cover for this video with the 2 spark plugs and notice the substantial difference between the incorrect old one with the washers and the correct new one that’s tapered and no washers that is much shorter.

[@jonathanmorrisey5771]

Get those plugs out of your engine!!!!! There are two different L98 cylinder heads. 1985-early '86 are cast iron cylinder heads and use the 1/2"reach tapered seat plugs. These heads have the traditional perimeter valve cover bolts. 1986-late thru '91 are aluminum cylinder heads and use the 3/4" reach plugs w/ a gasket. These heads have the center valve cover bolts. You have 3-4 cylinder head threads exposed to combustion gases and the plug is not sealed against the head.

[@Skizzags1974]

Good info Jonathan. I had not seen/heard of the variations.

[@45auto82]

Maybe use a magnet to see if heads are iron or aluminum?

[@LouisDanWhite]

Hey Chris, another great video which will 💯% help me out again. Can’t thank you enough for sharing your knowledge and that diagram 👌🏼 How did you find re-routing the spark wires around the back of the Diz? Was it as hard as you expected, any tips?

[@dukeman7595]

Yeah, slowly very slowly!

[@45auto82]

Wonder if that aluminum brite stuff you have would do as well on the steel exhaust manifolds? Or are you going with new headers when you do the exhaust sys? Just believe if staying, cleaning those manifolds up would add A LOT of POP to the look of your engine bay!

[@mycorvettelife]

It will work well on the heat shields for sure. I’ll be staying with the stock manifolds.

[@jly4517]

Am I the only one who saw the rust on the bottom of the coil and the condensor hold down? it looks like it got very wet at some time. plus the weights looked a little iffy too. I dont know if you cleaned it up some before you put everything back together but you should have..

[@albertrincones3403]

What is the gap of an iridium sparkplug in a corvette c4 1990...and wich iridium to use.

[@Clarity5970]

How did you unscrew one that broke,how did you put a new plug in?

[@mjot2360]

Passenger side you take the wheel off and go through the wheel well.

[@MrMany2811]

I removed all of the emissions plumbing and secundary pumps ,Is a piece of cake to do sparkplugs now

[@isambyrd986]

my old distributor cap had j hooks and the new one i bought does not, anyway i can get the new one to work or just buy another one

[@Brew6069]

Question for everyone. Looking at a 1995 C4 has 150,000 miles on it . The valve guides are being replaced the rest of the car is in pretty good shape but should I walk away from a car like this? Can purchase it for 5000$. What you think.

[@terryholston872]

If your new heat shield has "Velcro" fasteners on it, don't use it. It will burn and melt the Velcro and smoke up the place. LEAVE IT OFF it will be OK with out it. Ask me how I Know...LOL

[@johnseward4452]

I have a 87 vette and will not start it does turn over I put all new parts on it .but the next day I hit the Switch on it .and it fire right up kind you help me out

[@mycorvettelife]

So is the problem that it only starts when cold? It doesn't restart after its been running? Sounds like a fuel pump. I had a brand new fuel pump do this to me.

[@HellTriX]

Whats the modification list for this Red C4? The description seems to suggest a mod list for C5 and LS6/LS5 heads.

[@mycorvettelife]

All stock except for the muffler delete and Magnaflow cats.

[@87ferrarif40]

I did the passenger side from under the engine.

[@MrMartin405]

So you didn't change the omni spark on top or module in the the bottom either? 😂I'm thinking about going back in and changing them.

[@mycorvettelife]

I’m not sure what you are referring to...

[@MrMartin405]

The parts in the very top and the very bottom of the the distributor.

[@Rayzrs]

@@MrMartin405 you mean the coil and module

[@MrMartin405]

@@Rayzrs exactly I don’t know where Omni spark came from 😂

[@Jnzmbrn169]

I recently bought a c4 corvette, it runs and starts, but when I turn it on it shakes and after a few seconds it stabilizes, and gives a gas smell, what do you think is the problem, I'm thinking of changing, idel valve and tune-up, cap and rotor and spark plug wire, evrything new

[@mycorvettelife]

Leaking injectors

[@Jnzmbrn169]

@@mycorvettelife how can i fix that problem

[@mycorvettelife]

Replace them.

[@Jnzmbrn169]

@@mycorvettelife where can I buy the hem?

[@dukeman7595]

@@Jnzmbrn169 At any parts store..

[@cosmoLPINC]

what year is that?

[@Jnzmbrn169]

Where do you buy all that stuff

[@mycorvettelife]

Rock Auto, Amazon, local auto parts store

[@clydemoreno1845]

C4, except Lt1 , LT4 and LT5....and the dreaded CFI ofcourse...

[@donk6002]

I just replaced the spark plugs today on my 86 C4, driver side took 20 minutes passenger side took three hours of sweating and swearing but now she’s hitting on all eight ! worst spark plug change EVER !

[@FIipYap]

I ordered the wrong plugs

[@240greyhawke]

Hey Chris. Great video. I’m actually doing some work on my Corvette today. I am attempting to pull off the distributor cap right now, but find it extremely hard to get to the two back screws for the cap itself. What did you use to get them out?

[@mrdeanv4414]

What year is this C4?

[@mycorvettelife]

1988

[@mrdeanv4414]

@@mycorvettelife thanks... I just purchased a black 95 C4 with 87,000 miles in amazing condition

[@triple7441]

@@mrdeanv4414 how much?

[@mrdeanv4414]

@@triple7441 $9,500

[@dukeman7595]

Why didn't you change the condenser while in there? It appeared rusted and probably the original one, now with all that new and improved current it may burn out.

[@TheBlkac1]

Hello, Chris😁👍🏿 You just saved yourself about $2,000.00

[@dukeman7595]

$2,000.00 dollars? Where and what garage charges $2,000 to change 8 spark plugs, wires and a new distributor cap and rotor?

[@MattBerlin-c5t]

Those are the wrong plugs they should be longer for aluminum heads

[@johns6331]

Novice mechanic, wrong plugs used!! Must use washered plugs for alum heads; shouldered for cast iron.

[@timothyodell5245]

I must tell you that upgrade for the distributor was done incorrectly and should of been completely removed otherwise your car will not fire up.

[@bobsvette4834]

Why?

[@timothyodell5245]

@@bobsvette4834 the timing will require a base resetting.

[@danielkinsler46]

I am curious as to why as well

[@Skizzags1974]

The whole distributor does NOT have to be completely removed unless changing it all out. If it’s not defective, just the top end parts can be replaced. By replacing the cap, coil, rotor and plugs, Chris installed the same way he took apart. The timing doesn’t change at all. Chris did it right and it should fire right up as long as it was wired just like his drawing showed.

[@mycorvettelife]

I must tell you, it started and runs perfectly fine.