1975 Plastic fantastic aka Corvette

[SuperBuickGuy]

something with vacuum. MAF works on air flow plus what the 02 sensor reads. with a loopity cam, the airflow isn't steady (for a good reading), and at idle it thinks it's not running right because the exhaust is too cold for the O2 sensor to work correctly. I may have been able to mask part of the problem by moving the O2 closer to the motor, but even so, I may have also caused it to be worse depend on how often the cylinder wouldn't fire at idle (or get a complete burn).

I may have been wise to keep the EFI for the FJ40, but even so, I wheeled with carbs for years and never really had a problem with them... I know how the problem occurs, mind you, but frankly I could go on 10 trips and never have the issue (WOT, bouncing uphill causes fuel starvation problems that don't exist with efi).

[Beagle]

SD tune can get around your (is that Lumpity or Lopity or are you just being Loopity) cam idle issues.

LPG!

[SuperBuickGuy]

on a Corvette? how dumb is that - next thing you'll tell me they've tried this with a Chevelle....

I've said this before, and I'll say it again...

Everyone needs to get a cam that is too radical for their car and they need to make it work. If you can tune that kind of persnickety beast, then when your truck has a slight miss above idle you'll know that you need to check your butterfly valves, your transition circuit, and your spark plug wires for the problem - or if EFI, you'll know to check the O2 sensor, the injector pulses, and the fuel filter. It really does make you a better mechanic because they're so temperamental that slight problems are exaggerated - and easier to find and fix.

[Deaf Bob]

I learned the HARD WAY what a leaking header tube sounds like.. After a playful row, I developed a KNOCK! Or so I thought.. To my poor hearing and my feel ( fenderwell headers AMPLIFY stuff) It sure felt like a knock.. All it turned out to be was the gasket blowing on the top of the port.. Now I use a large screwdriver on each port to "hear" for the knock! I even "diagnosed" a knock in a derby motor for my son's buddy.. They were nodding happily that they got motors swapped in time, I was sitting on tires by the front wheel, shaking my head no.. I could feel the knock in my water bottle.. Handed it to them, they then heard it over the open thru the top exhaust.. Nothing else teaches you with the exhaust less than a foot grom your head.. Feel stuff as it runs.. Learn what you should feel.. Betcha get surprised someday!

[Beagle]

LPG for the Feep!... you're talking about multiple projects in your thread and I'm replying to them in order.

...

... (WOT, bouncing uphill causes fuel starvation problems that don't exist with efi).

If your gonna go all ADD and talk about multiple vehicles in your posts, at least keep up with the replies? Unless, that is, you intend to bounce the 'vette up hills hard enough to cause float movement or jet coverage problems, in which case I own you an apology and congratulations!



FWIW, I think the Olds looks better than a Chevelle, but a 'vette would do in a pinch.

[SuperBuickGuy]

You've obviously never driven Pacific Speedway, it winds its way up a hill and over the berms. Of course, that's presuming you're motor has survived the oil starvation issue that arises at the bottom of that hill...

ADD bah, that's child's play.

[Beagle]

The only thing they would rent me on my visit to Redmond was a GM versioned GEO Prism nee Toyota Corolla, which doesn't go fast enough to generate the forces necessary for any kind of starvation - except maybe attention! They did try to give me a 1990 LeMans but it used 5 gallons of gas between SEA and Renton and I "raced" it back (the race was to see if it was going to run out of gas) threatening to set it on fire in the driveway. There is probably still a black smoke trail on the 5. Not one of GM's better ideas...



my last few years as a slave to GM were not good years.

[SuperBuickGuy]

you're lucky they didn't give you a Leaf.

[SuperBuickGuy]

It runs again... I have a bunch of little things like oil caps and tightening the headers again... but it runs so I can move the stuff that needs fixing back into the shop.

[Deaf Bob]

Too bad it is too wet and leafy to go on a hard charge...

[SuperBuickGuy]

it needs tuning, again, so no hard charging for a bit.... right now, getting it off the injured list is a good thing because if my Hummer goes down - I'm driving it.

[JOES66FURY]

hehe "hummer" "goes down"

[Deaf Bob]

hehe "hummer" "goes down"

Just replace batteries, good to go..

[SuperBuickGuy]

Just replace batteries, good to go..

[SuperBuickGuy]

if you look closely, you will see a finished (now silver) product