Got the C4 on a lift today...

"JayZAyEighty thinks C4+3=C7" (jayzayeighty)
06/23/2014 at 13:06 • Filed to: None

Its battery won't hold a charge with the engine off and takes forever to get the car started, so it needs an alternator. I had to get a jump start last night and this morning. The first things it'll need are probably suspension components, because the car was not handling imperfections on road at all and some bushings looked busted. All in all, it drove nicely and was structurally and mechanically good. It pulls hard as it should, but people still love to be assholes and tailgate you due to their distaste of the car. Oh yeah, and honking for no reason. No Corvette drivers do the wave, either. There were three other C4s in the parking lot where I waited, though! The engine and transmission could both run a bit more smoothly, but some seafoam along with a tuneup and new gear oil should remedy that. It'd definitely benefit from a nice steering wheel and shift boot on the inside, but I don't know that it would be able to replace the shift knob and still be able to engage overdrive. Overall, things were good and there wasn't a single major red flag. Not bad for a $5000 craigslist 'vette.

DISCUSSION (17)

MontegoMan562 is a Capri RS Owner > JayZAyEighty thinks C4+3=C7
06/23/2014 at 13:10

these guys should have your steering wheel and shift boot. I don't think they have the knob tho:

http://www.corvetteamerica.com/cf/interiors.c…

Jake - Has Bad Luck So You Don't Have To > JayZAyEighty thinks C4+3=C7
06/23/2014 at 13:22

How well does seafoam work? I've been thinking of going to *local auto parts store* and running a bit through lessie to see if that nets me a little lost power.

Zoom > JayZAyEighty thinks C4+3=C7
06/23/2014 at 13:23

Its battery won't hold a charge with the engine off so it needs an alternator.

Ouch, bud. This statement hurts to read.

If you have a known dead battery, and a jump start gets the car to run by itself, the only place you are getting power is the alternator.

Don't get me wrong because you may have mis-stated your dilemma, (and the fact that most GM alternators of the era were complete garbage). But before you rip into an alt, make sure it is indeed not putting out power, and there are no key-off drains.

JayZAyEighty thinks C4+3=C7 > Zoom
06/23/2014 at 13:29

Hah, I didn't fully explain. It takes half an hour before the battery has near enough charge. I tested the alternator using a battery tester, and the alternator hardly converts any charge. It's definitely the alternator.

JayZAyEighty thinks C4+3=C7 > Jake - Has Bad Luck So You Don't Have To
06/23/2014 at 13:36

I've heard it works well, but is only super effective if you do the extensive process. Here's a link on how to do it so that it really makes a difference. I'll do it as soon as I'm able to put the miles on by getting tags. http://m.ls1tech.com/forums/showthr…

Zoom > JayZAyEighty thinks C4+3=C7
06/23/2014 at 13:36

GM injectors of the day were also very unreliable and will contribute to a rough run, stall, and part throttle stumble. The good part is they are easy to test resistances to see if they are bad. If ignition does not remedy your driveability issues suspect injectors or intake gaskets/ported vaccum leaks.

JayZAyEighty thinks C4+3=C7 > MontegoMan562 is a Capri RS Owner
06/23/2014 at 13:40

Awesome, they do! Although I doubt there are any compatible knobs... still good to have the button on the shifter.

Rock Bottom > JayZAyEighty thinks C4+3=C7
06/23/2014 at 13:43

I've always wondered about that Doug Nash 4+3... does it automatically shift into OD in each gear, or is there a shift button of some sort that allows you to engage it whenever you want?

JayZAyEighty thinks C4+3=C7 > Rock Bottom
06/23/2014 at 13:55

It's basically a Super T10 mated to a Powerglide 3 speed for overdrive ratios on the top three gears for improved fuel efficiency and noise reduction. It can automatically engage overdrive between gears, or the driver can manually engage/disengage overdrive by pressing the button on top of the shifter (and use it as a regular 4 speed manual with OD in 4th). It has long throws and was originally developed for RVs, but was the only current manual strong enough for the TPI 350's torque and efficient enough for the EPA's regulations. In time, it was replaced by a superior ZF 6 speed but I think the 4+3 adds character to the car.

MontegoMan562 is a Capri RS Owner > JayZAyEighty thinks C4+3=C7
06/23/2014 at 14:02

yea those corvette america guys have quite a bit of good stuff, search around their site now that you're a Vette owner.

I used to get their catalog when I was young and obsessed with Corvette's cause it was free and enjoyable to flip through haha.

Rock Bottom > JayZAyEighty thinks C4+3=C7
06/23/2014 at 14:04

Ahhhh! I kinda want one now!

JayZAyEighty thinks C4+3=C7 > Rock Bottom
06/23/2014 at 14:13

Haha just don't ask me how it is when the novelty wears off. It requires so little shifting, but gives you good highway mileage at low RPMs. That's definitely the upside. It doesn't need tons of gears with the low-end grunt, so it works fine performance-wise. It gets a bad rap, but really doesn't deserve it—people who complain about their experience with it probably didn't clutch in when engaging/disengaging or replace ATF in the OD unit, which is definitely important. Anyways, there's my .02. You have a C5?

JayZAyEighty thinks C4+3=C7 > MontegoMan562 is a Capri RS Owner
06/23/2014 at 14:59

Haha it'll definitely be useful but I have a feeling I'll be "needing" a lot of stuff now!

Rock Bottom > JayZAyEighty thinks C4+3=C7
06/23/2014 at 15:06

Oh, you have to clutch-in when shifting the OD? That's pretty interesting. Sounds almost like the 2-speed unit on a semi truck! Out of curiosity, what kind of real-world fuel economy are you seeing?

Yeah, I picked up a super clean C5 a couple months ago and love the hell out of it! It's transmission is far less exotic than yours, though. Plain Jane T56 for me!

MontegoMan562 is a Capri RS Owner > JayZAyEighty thinks C4+3=C7
06/23/2014 at 16:51

Hahaha OOPS (but not really)

JayZAyEighty thinks C4+3=C7 > Rock Bottom
06/23/2014 at 19:36

Yeah sort of! TBH I have driven the car 50 miles, tops. All traffic-y city driving. But 16 MPG, so not bad. According to PO, it has a mild cam. Who knows. Also, C5 sounds great... enjoy that LS1 and actual road-tuned suspension!

Rock Bottom > JayZAyEighty thinks C4+3=C7
06/24/2014 at 10:18

And you enjoy having the first generation of 7 speed Corvette!