Roadkill's 1983 Chevy Z28 - (Work Starts on Page 5)

[Incursus]

huh huh you said penetration huh huh

[ianjpage]

Quoting: Roadkill

Steering bracketry is off the K-Member . .. didn't need cutting . . . a few clouts with a nylon mallet and they broke of leaving very little behind . . . a quick buzz with a linishing disc and it'll be as good as new.

Not sure if that's a good thing or not . . .

It looked like we were getting good penetration but clearly not.

oh that's good for the replacement purpose but not for fixing purpose, obviously wasn't penetrating deep enough (yes i know pun city!)

[Titsy]

Quoting: Roadkill

No, crap. But I know a man/some men who can.

Stick it on the 20v range, put the black on the earth bond of the alternator and the red on the main alternator terminal and see what you get...

You should be seeing about 13.8-14.4v when running. If it's a little low try reving it to 2k rpm and see if it picks up. If it's lower than that there is probably an issue... If it's ok at the alternator but low up stream there is probably a corroded terminal or loose connection somewhere.

[Andy]

Quoting: Titsy

Stick it on the 20v range, put the black on the earth bond of the alternator and the red on the main alternator terminal and see what you get...

Do this, but without the main alternator output cable connected otherwise you'll still be measuring battery voltage in circuit.

[Roadkill]

We got :

Initial timing 13-14 degrees @ 700 RPM - seems happy.

With Mech advance 33 degrees @ 2500 RPM - seems happy.

Got up to 60 degrees with Vacuum re-connected @ 2500-3000 RPM (seems high and did pop and bang a little bit on throttle release ??)

[ianjpage]

Quoting: Andy

Quoting: Titsy
Stick it on the 20v range, put the black on the earth bond of the alternator and the red on the main alternator terminal and see what you get...


Do this, but without the main alternator output cable connected otherwise you'll still be measuring battery voltage in circuit.

Did some testing todya - looks like no output as whatever we were reading @ battery, was the same on the alt terminals, irrespective of rev's.

Didn't get round to disconnecting main terminal (mainly cos it's a PITA!) but unplugged the multi plug and again no difference

Started @ 11.4 v this morning (battery & alt) then by end of day when car wouldn't then turn over was 10.3v, so defo not charging.

Would it be worth a pull apart and try to diagnose the fault or not?

[Andy]

Quoting: ianjpage

Did some testing todya - looks like no output as whatever we were reading @ battery, was the same on the alt terminals, irrespective of rev's.

Didn't get round to disconnecting main terminal (mainly cos it's a PITA!) but unplugged the multi plug and again no difference

Started @ 11.4 v this morning (battery & alt) then by end of day when car wouldn't then turn over was 10.3v, so defo not charging.

Would it be worth a pull apart and try to diagnose the fault or not?

For the alternator to work the multiplug has to be connected due to it supplying the exciter voltage. Without this the alternator won't work.

The next step would be to check the multiplug for a voltage on either of the terminals. I can't remember which one it is exactly but my plug had two wires, one thinner than the other. The thicker one should be supplying an 'accessories on' voltage of around 12-13v, this is the exciter voltage required for the alternator to make an output.

If when you check with the accessories on you find you have a voltage then it likely the alternator is duff, and you are in the same boat as I was a couple of months ago. In which case I'd recommend Real Steel in Uxbridge who next day'd me a brand new unit for just shy of £90.

If you don't have a voltage with the accessories at the multiplug, then you may be looking for problems further up the wiring chain.

Just so you know, it sounds exactly the same as the problems I had with mine, the only difference is I thought getting my alternator refurbished would be easier but it wasn't.

[ianjpage]

Quoting: Andy

For the alternator to work the multiplug has to be connected due to it supplying the exciter voltage. Without this the alternator won't work.

Yeah thought as much hence checking with & without!

Quoting: Andy

The next step would be to check the multiplug for a voltage on either of the terminals. I can't remember which one it is exactly but my plug had two wires, one thinner than the other. The thicker one should be supplying an 'accessories on' voltage of around 12-13v, this is the exciter voltage required for the alternator to make an output.

Hmm dean's only got 1 wire on his...

Quoting: Andy

If when you check with the accessories on you find you have a voltage then it likely the alternator is duff, and you are in the same boat as I was a couple of months ago. In which case I'd recommend Real Steel in Uxbridge who next day'd me a brand new unit for just shy of £90.

It was running with pump, fan, fuel etc all running BUT the wiring has been totally redone so not sure if this would still be applicable (TISTY??)

[Titsy]

If I remember rightly and you've used an alternator for the LT1 then the main terminal is all that's required for the generated output and all regulation is internal. the plug on connector only has one with which is for the electrical warning light...

EDIT

found this: http://shbox.com/1/starter_charging_95.jpg\" target=\"_blank\" rel=\"nofollow\">http://shbox.com/1/starter_charging_95.jpg

So if you short the plug on cable to ground (do this through a fuse) it should blink the generator light on the dash. There's nothing else to get wrong really assuming you selected the right alternator when you replaced it.

I presume you don't have to original from the donor to swap in?

[Andy]

Quoting: Titsy

If I remember rightly and you've used an alternator for the LT1 then the main terminal is all that's required for the generated output and all regulation is internal. the plug on connector only has one with which is for the electrical warning light...

EDIT

found this: http://shbox.com/1/starter_charging_95.jpg\" target=\"_blank\" rel=\"nofollow\">http://shbox.com/1/starter_charging_95.jpg

So if you short the plug on cable to ground (do this through a fuse) it should blink the generator light on the dash. There's nothing else to get wrong really assuming you selected the right alternator when you replaced it.

I presume you don't have to original from the donor to swap in?

Yeah, I'll agree with that. I think that means if you have got a CS130 alternator like the one fitted to 3rd gens with engine codes E and F you won't have the correct wiring for it.

Check here on page S3/37 - I don't know the engine that well but you may be able to cross reference it to one on there? http://realsteel.co.uk/section3b.pdf\" target=\"_blank\" rel=\"nofollow\">http://realsteel.co.uk/section3b.pdf

[Roadkill]

Quoting: Titsy

and you've used an alternator for the LT1

No, it's a CS 130 - Smaller type to allow me to mount it low on the new brackets.

Quoting: Titsy

I presume you don't have to original from the donor to swap in?

No.  Long gone.  Not even sure I ever had it.

UPDATE -

As mentioned above - we had a play with the timing and actually got it running WORSE !!!

It took quite a bit of playing to get it where it seemed happy but this isn't 100% where I'd expect it to be . . Jaime - any ideas ????

Quoting: Roadkill

Initial timing 13-14 degrees @ 700 RPM - seems happy.

With Mech advance 33 degrees @ 2500 RPM - seems happy.

Got up to 60 degrees with Vacuum re-connected @ 2500-3000 RPM (seems high and did pop and bang a little bit on throttle release ??)

Am intending on replacing the dizzy/cap/arm eventually (not yet, though) as it's the only real unknown.  
For $200 I can get a Moroso with adjustable vacuum advance, new cap and new arm . . . more money but at least it'll give me some control - the dizzy comes with different springs so mechanical advance as well as vacuum can be fine tuned.



We got the new slam panel fixed (but I think I'm gonna replace the fixings with new ones as the old are a bit manky) . . .

Had to drop the hood on to check the lines as the nose meets the bonnet so thought I'd get some pics.







Bonnet's back off again to let some light in while I ponder the steering bracket issues . . . . . .

Also.  The list.  Looks good but need to add a few soon . . .

[Incursus]

Looking the dogs danglies

[Andy]

I guess it's a question of whether the wiring harness in the car is suitable for the alternator?

Did the wiring come with the engine?

I think the cs130 is fitted to most sbc but if the wiring diagram posted by Titsy above is the same as the one in your engine bay, then it won't work unless you supply the correct feeds to the correct pin outs.

So at best guess, two options are fitting a correct alternator (real steel link above should have one you need) or fashioning up your own bit of wiring to supply an acc on 12v feed to it.

[Jamieg285]

Quoting: Roadkill

As mentioned above - we had a play with the timing and actually got it running WORSE !!!

It took quite a bit of playing to get it where it seemed happy but this isn't 100% where I'd expect it to be . . Jaime - any ideas ????

Quoting: Roadkill
Initial timing 13-14 degrees @ 700 RPM - seems happy.

With Mech advance 33 degrees @ 2500 RPM - seems happy.

Got up to 60 degrees with Vacuum re-connected @ 2500-3000 RPM (seems high and did pop and bang a little bit on throttle release ??)

60 is definitely too high.  

I'd expect the vacuum to drop as you rev it, so that as the mechanical kicks in, vac-advance drops keeping it around the same sort of 30-40 level (I do not confess to be an expert on the actual figures though). I believe that the faster the engine speed the more advance you need.

When you set timing with the vac disconnected - did you plug the pipe to prevent a vac leak?

Do you have a vacuum gauge?  What readings are you getting from the pipe connecting to the vac-can, at idle and up to the 3K revs?

[Titsy]

Quoting: Roadkill

No, it's a CS 130 - Smaller type to allow me to mount it low on the new brackets.

Ok so now I know what's wrong... you need to trace the red plugin wire away from the alternator as far as possible so that when cut it is long enough to wire into the red junction on the bulkhead.

This won't give you a charging warning light on the dash as you would need a different pigtail, but if you get the right pigtail the loose end of the cut wire should be left so that the warning light could be attached to it.

[ianjpage]

Quoting: Titsy

Quoting: Roadkill
No, it's a CS 130 - Smaller type to allow me to mount it low on the new brackets.

Ok so now I know what's wrong... you need to trace the red plugin wire away from the alternator as far as possible so that when cut it is long enough to wire into the red junction on the bulkhead.

This won't give you a charging warning light on the dash as you would need a different pigtail, but if you get the right pigtail the loose end of the cut wire should be left so that the warning light could be attached to it.

OK so the red "live" terminal inside teh lil black box ?

[Andy]

I never posted these on my thread when I was going through the stages but they might be useful here.

This is a photo of the plug fitted to my CS130, its a 4 pin plug but only two of the pins do anything. This alternator will not work with out the plug inserted.





The thicker cable I am almost 100% sure is the acc on live feed. This comes from the fuse board or similar area but has a resistor in series to lower the voltage from exact battery voltage.

Here is a video of me testing my 'refurb'd' Unit. I was going to use this as evidence in case they kicked up a fuss about it working for them.

This shows it mounted, with the multiplug connected, but the main battery terminal disconnected (and the cable taped up as it is effectively a live cable)

You then see me showing the battery voltage, to prove I was at least running a charged battery. I then connected my second volt meter to the output terminal. This is measuring the alternators 'output' across itself using the casing as a ground.

http://i296.photobucket.com/albums/mm162/andydpics/CE25CC36-F9B6-4678-8D2C-CB50100FB49C-31433-000003BBAE95BA3E.mp4\" target=\"_blank\" rel=\"nofollow\">

[Titsy]

The red wire labelled 'S' is the sense wire for the regulator. This is so that any volt drop to the distribution block is accounted for.

[ianjpage]

@andy - dean's connector has 1 thin red wire... plus am sure the conn. is different to that as well, could be wrong tho

@titsy - erm can i have that sentance with teh missing words please

[Roadkill]

Jamie.

A guy on thirdgen.org reckoned 36 degrees mechanical all in at 2500 RPM, then said 52 degrees max with vacuum.  Or at least that's what I think if said.  He typed in text speak.



He's the only one to respond to my thread ...

I don't have a vacuum gauge, no.

A sensible purchase maybe, though.

[Titsy]

I can get you the PCM timing table for the LT1 once I manage to dig out my old laptop with the tuning program on... If that's any help

I'd guess you'd want less advance than that shows though as your compression is likely to be up a bit after a skim and helping it breath...

Might be worth checking your compression so you know what your playing with...

[Andy]

Quoting: ianjpage

@andy - dean's connector has 1 thin red wire... plus am sure the conn. is different to that as well, could be wrong tho

Ah i see, thats what I was trying to ask this morning, whether the wiring loom is for the alternator fitted to an LT1 or if it is one for a CS130. The LT1 according to that diagram Titsy posted has a different internal wiring, compared to the CS130 Dean has fitted.

This is apparently the small plug connected to an LT1 Alternator:



Now if this is what is fitted on the loom, simply hooking it up to a 12v feed won't cure the problem, you'll have to shift over which pin it connects to, making it the 'S' terminal instead.

If you two are able to get at the plug, one way to see if you can get the alternator working is by getting a fairly chunky bit of cable connected to the positive battery terminal, have in series a 500 ohm resistor, then disconnect the multiplug and connect that to the 'S' terminal. This should induce the alternator to output a voltage. All you'll need to do is then wire this up properly.

[Andy]

Just to add...

[Jamieg285]

Done a bit more reading...

You may need to rev a bit higher when checking your total timing - It may be that you're not all in a 2.5K.  Slowly take it up to 3.5K - you'll get to a point where it stops increasing.

13-14 sounds a bit high for initial - most recommendations are 8-12.

Vac advance does vary (because the vac pull varies as the engine does different things), but will still add when cruising, in which case a combined total of ~50-55 can be expected.  

Are you using a ported or full vacuum for the vac-advance?  I'd expect you to be using timed with a manual transmission.

[Roadkill]

I read that an initial at below 10 can be hard to achieve with a bigger cam . . . my cam is fairly big and she didn't seem happy idling below 13.

I couldn't get the idle down to 700RPM at 10 degrees - she needed more like 900-1000 RPM to keep her ticking over.

That said I'm happy to keep fine tuning, obviously.

Either way with vacuum it seems way too high.

I'm guessing something like this : http://www.ebay.co.uk/itm/290783770609?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649\" target=\"_blank\" rel=\"nofollow\">http://www.ebay.co.uk/itm/290783770609?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 is what I need to test the vacuum.

I've seen more expensive ones about but this should do the job shouldn't it ??

EDIT - I'm using Ported Vacuum . . . .