HEI Module

N

nate chase

New member
Apr 26, 1999
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Out of curiosity has anyone ever had a
Toro distributor module in their coach?
Just wondered how it would react? Ping
alot due to a faster advance curve
perhaps? Or would you have to retard it
more than usual to compensate for the
quicker advance? Just some thoughts...

I retarded mine early this AM to 10
degrees advance at 600 rpm (with vacuum
adv blocked off) which is less than the
12 degree adv. the Caspro EKE
instructions call for. I still get a few
seconds of ping every so often under
load. Heck, if I goto 8 degrees to stop
the ping what's the sense of having the
EKE sensor in the first place?

I would like to get it to the point of
1,2 or a few pings but 3-4 seconds worth
seems like a lot to me. Maybe my best
bet is to simply replace the HEI module
and use this one as a spare. Anything
else I should be aware of here? Adv
springs or weights? Suppose I shoulda
probably sent the darn distributor to
Caspro when I got it back from JB in
Forest City.

Is the NAPA (TP45) or the Delco
(1875990) module any better than the
other?

Nate '75GB (Ping, ping, ping... EKE!)
Omaha
 
Geez, just priced out the module.

NAPA TP45 $36.10
GM Delco 1875990 $41
Autozone Delco cross ref $10.99

Nate 75GB (Pays to shop around, huh?)
Omaha
 
remember they are not all the same or same quality. You might have to add
a diode for example with the non gm part

gene

>Geez, just priced out the module.
>
>NAPA TP45 $36.10
>GM Delco 1875990 $41
>Autozone Delco cross ref $10.99
>
>Nate 75GB (Pays to shop around, huh?)
>Omaha
>
>
>
>
Genef -- 77PB/ore/ca
GMC MOTORHOME INFORMATION
mr.erf
http://www.california.com/~eagle/
 
With modules, you get what you pay. The cheap ones don't last.

Bill Macdonald
- -----------------------------------------
(503) 526-8649
eieioh

- ----- Original Message -----
From:
To: "'GMC'"
Sent: Tuesday, June 06, 2000 2:51 PM
Subject: GMC: HEI Module

> Geez, just priced out the module.
>
> NAPA TP45 $36.10
> GM Delco 1875990 $41
> Autozone Delco cross ref $10.99
>
> Nate 75GB (Pays to shop around, huh?)
> Omaha
>
>
>
>
 
Nate,
Arch hit the nail on the head. There is no guarantee that just because a
timing light says you're set at 8 degrees BTDC that you're there. The
timing marks are probably accurate within 5 degrees. That's why Caspro has
you tune it by feel. The knock eliminator just lets you run all these
different gas formulations without tinkering every time you fill with gas
and still have a close to optimum cruise timing.
Bob McLaughlin

- -----Original Message-----
From: owner-gmcmotorhome
[mailto:owner-gmcmotorhome]On Behalf Of chase
Sent: Tuesday, June 06, 2000 4:43 PM
To: 'GMC'
Subject: GMC: HEI Module

Out of curiosity has anyone ever had a
Toro distributor module in their coach?
Just wondered how it would react? Ping
alot due to a faster advance curve
perhaps? Or would you have to retard it
more than usual to compensate for the
quicker advance? Just some thoughts...

I retarded mine early this AM to 10
degrees advance at 600 rpm (with vacuum
adv blocked off) which is less than the
12 degree adv. the Caspro EKE
instructions call for. I still get a few
seconds of ping every so often under
load. Heck, if I goto 8 degrees to stop
the ping what's the sense of having the
EKE sensor in the first place?

I would like to get it to the point of
1,2 or a few pings but 3-4 seconds worth
seems like a lot to me. Maybe my best
bet is to simply replace the HEI module
and use this one as a spare. Anything
else I should be aware of here? Adv
springs or weights? Suppose I shoulda
probably sent the darn distributor to
Caspro when I got it back from JB in
Forest City.

Is the NAPA (TP45) or the Delco
(1875990) module any better than the
other?

Nate '75GB (Ping, ping, ping... EKE!)
Omaha
 
Tom,

Read it again. Your statement is technically correct, but out of context.
Nowhere in his post does Rick state that you can compensate for an out of
time cam with ignition timing. Specifically, pay close attention to the
paranthetical comment in each paragraph.

I don't speak for Rick, but I believe that his point was that both the cam
and distributor are timed in reference to the crank and not each other.

Patrick

>
> Sorry Rick but it most certainly does matter if the cam is
> off. YOu can not compensate an out of time cam with IGNITION
> timing.
>

> >
> >Arch,
> > When you set ignition timing, you reference it to the
> >crankshaft pulley, not to the camshaft. Therefore, it
> >doesn't matter if your camshaft timing is off, as you
> >compensate for that (in respect to ignition timing) when
> >you get out your timing light.
> > Bottom line: if you set base ignition timing to 8 deg.
> >BTDC, 8 degrees it is. (Valve timing may still be off,
> >of course.)
> >
> >HTH.
> >
> >Rick Staples
> >'75 Eleganza
> >Louisville, CO
> >
> >
>
 
I work at Dana Corp who recently bought Echlin who supplies
many NAPA parts. Several years ago I was the project
engineer for ACCEL distributors made here in Branford Ct.
as part of my job I had occasion to have ignition modules
tested with a variety of different ignition coils. Gene has
a valid point. We actually documented the fact that some
TP-45 type modules would not fire some coils at a given
range of RPM (generally the ones made off shore). The
module would literally drop out and not fire the coil for
instance from 1,200 rpm to 1,250 rpm (this can cause really
hard to diagnose performance problems). I am not an
electrical engineer I just know what we recorded. Bottom
line, it is best to get a coil and module for the same
application and probably best from a dealer. I wish I could
say that I am sure the NAPA TP-45 modules are the good
ones, I can't, but I bet the $10.99 unit is made off shore.
Any takers?

>Date: Tue, 06 Jun 2000 15:23:18 -0700
>From: gene
>Subject: Re: GMC: HEI Module

>remember they are not all the same or same quality. You
>might have to add a diode for example with the non gm part

>gene

>>Geez, just priced out the module.
>>
>>NAPA TP45 $36.10
>>GM Delco 1875990 $41
>>Autozone Delco cross ref $10.99
>>
>>Nate 75GB (Pays to shop around, huh?)
>>Omaha

=====
Alan Bredbury
Clinton, Ct.
1974 GMC 26' Classic Motorhome
http://www.finesttool.com/index.html/special.htm

__________________________________________________
Do You Yahoo!?
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8 degrees plus or minus all the manufacturing, marking and use tolerances
associated with the timing marks. That's probably not more than 5 degrees.
Bob McLaughlin

- -----Original Message-----
From: owner-gmcmotorhome
[mailto:owner-gmcmotorhome]On Behalf Of
RickStapls
Sent: Wednesday, June 07, 2000 12:08 AM
To: gmcmotorhome
Subject: Re: GMC: HEI Module

In a message dated 6/6/00 4:05:33 PM Mountain Daylight Time, Gcbr
writes:

> Just for kicks we degreed in the
> old cam before we took it out. It was not even close. Setting the timing
> at 8 degrees BTDC was really firing at TDC. I think this is why I did not
> have a ping problem with the Toro HEI.

Arch,
When you set ignition timing, you reference it to the crankshaft pulley,
not to the camshaft. Therefore, it doesn't matter if your camshaft timing
is
off, as you compensate for that (in respect to ignition timing) when you get
out your timing light.
Bottom line: if you set base ignition timing to 8 deg. BTDC, 8 degrees it
is. (Valve timing may still be off, of course.)

HTH.

Rick Staples
'75 Eleganza
Louisville, CO
 
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