pauldana

76rat took the plug out and fired the coil via hand to watch the spark in the plug... it looks very good.

pauldana

Also... my batter is somewhat bad... so maybe it is no longer filtering the A/C pulse from the alternator as well????

gkull

Even off 8-10 degrees is not a big deal it will just smooth out when you dial it in. I have engines with different firing orders so I always have to recheck my work to ensure I am correct.

pauldana

But being as much as 3* off in the cap and HB timing mark settings could make the spark jump to the wrong terminal.

pauldana

just another tid bit of info...

it sparks in #8, fuel is in #8, compression and leak-down are good in #8...

But the temp gauge shows more than a 200* temp drop in that tube as compared to every other tube/.....

MrJlr

BOTH of my rear cylinders (7 & 8) measure cold with my IR gun when I measure them from the top of the header....NO IDEA WHY

But if I point the beam kinda at the side of the tube, I get a much better reading....

Kinda confuses me but I know they're firing...If I had 2 holes not burning, it would be pretty obvious.

diehrd

1 8 4 3 6 5 7 2 .. how 8 is by the fire wall is past me .. It should be behind T/B ..

Set it all up in as basic configuration as you can and fire it up.

zuendler

nothing new, it´s a known issue with thoes IR guns on metal surfaces.
My gun has a problem on sand blasted aluminum (alternator).
But it works good on chrome, where other guns have problems.
If you measure the headers the important thing is to see no big differences between them. Idle temp is only interesting to detect missfire there. More interesting would be the exhaust gas temp under load. This would tell you as much as an AFR-meter.

diehrd

So what exactly is the running issue ??

bluedawg

That's what I was asking about, what's the evidence that number 8 is miss firering? I mean the plug is sooty, not wet, seems the valve is adjusted and fire to the plug.

pauldana

Issue.... runs rough, backfires, missis....

another idea of a possible problem... my battery... its bad, good enough to crank over the car right after a charge, but more than 15 sec of starting and its toast for another charge,,, in this state it does not filter the AC, or pulsed DC or spikes produced by the alternator very well, thus inducing noise into he system....

So, i had a little time last night and was going to try my new light weight 15 pound battery... started looking for it... looked for an hour?!?!?!?! where was my light weight battery!?!?!?! texted Danny and Chris... yea, Danny had it... he's making a bracket for it, so he can fit one in his C5!!! ill get it back today and see what difference it may make..

bluedawg

Do you have a replacement battery?

Bee Jay

Can you target your Air/Fuel ratio. I have an old skool Holley 4Di unit. My car would not run worth a damn using 14.7/1 ideal stochiametric (sp), but runs like a bat out of hell, or like a sexually assaulted semian (raped ape) at 13/1. I guess big cam, big heads, big exhaust, big inches require a rich mixture. I also have to run big amounts of timing. I hope to upgrade to the modern Holley fi unit.
Just sayin'.
Bee Jay

pauldana

bluedawg getting my battery back today from Danny:-)


Bee Jay the EZ-EFI 2.0 auto tunes the A/F mixture, I can enrich it or lean it out, but when observing the reading i was seeing it balance out around 13:1 for the little time it ran....

I'm going to rerun some wires, put in the new battery and see if that helps.. if not, i am going to stab my old distributor back in and see if that fixes the problem.. after that my old carb.... its a defeating feeling...

MotorHead

Engine should run half decent on 7 cylinders or even if you have wires crossed.

Have you tried taking the plug wire off the # 8 cylinder and see if it runs.

Don't get me wrong here but I would have used a know good carb and intake and once I got that dialed in I would put the EFI on. Just way too many variables doing it all at once

StraubTech

Paul,
I agree with Motorhead, at this point I would drop an HEI in her and borrow at 950 carb and get the engine running. This way you can check for leaks, be sure valves are adjusted, get the rings seated in, and let her run on break in oil. Take a leak test and cylinder pressure test on her. Once that is done go back to the EFI.

pauldana

I think it is a gremlin in my electrical system...

here are my planned steps

1. Change battery... (did this last night, the old one was completely toast) with new 15lb light weight battery..... do not believe it was filtering like it is supposed to in its state

2. put on ground straps to the carb/throttle body and heads and what ever else i see that i think needs a ground strap

3. Reroute any wire/wires from the EZ-EFI that come anywhere close to any electronic or ignition system on the Vette.

4. put a cap right off the alternator

5. double and triple check distributor alignment and rotor alignment (how much play in the rotor should you have? i can move my rotor about +-2-3* from the play in the gears)


if none of the above work:-(

1. Remove distributor and replace with a standard unit.
test car

2. Remove throttle body and replace with standard carb.
test car

pauldana

Hey Chris.... Dannys C5 427 Guldstarnd you can NOT make faster than Baby!!! would never ever live it down if that car can beat me at the track!!! right now i woop on his butt... don't want that to change here anytime soon!!!:-)

bluedawg

1) you've confirmed that you getting spark @ number 8?
2) if it's a throttle body and not tuned port, if it weren't getting fuel you'd have other cylinders that wouldn't be getting fuel as well being a single plane intake?
3) compression tests show that's in the ball park.
4) so about the only thing I can thank of is a vacuum leak at the interface of #8 intake runner and intake manifold. Have you had a vacuum gauge hooked up? How thick of gaskets do you run?

pauldana

4. no... how do you suggest doing this??

i have seen a spark in #8 when manually made to spark,,, when engine not running... will try and start her again tonight for tomorrow after grounding work and caps are installed.