Ditching LeanBurn on a 1987 Fifth Avenue

Yeah, but "everybody" has the Mopar EI module over the counter too.
Heck, it was used, virtually unchanged (and backward compatible- the
later 4-pin modules just ignore the 5th pin and its still in the
connector) for 20 years!

To be honest, HEI does have a slightly hotter spark. But to me its not
worth the added unreliability and non-standardness (is that a word?) of
a hybridized system.

 

I had a 79 Fury Sport 318 with electronic ignition on it but no lean
burn only thing I ever had a problem with was I changed 2 ballast
resistors, I did all kinds of things to that car, sure I went thru 3
trannys and a rear end but I drove the crap outa that car, even put a
4bbl on it, got the intake of a 340, it had 300,000+ on it when I parked
it, tossed a couple quarts of straight 50 down the carb till it stalled
at full throttle and it sat for 3 years after that till I had to send it
to the junk yard, and I drove it there, took 2 BIG batteries and with
one in a running truck to get it turned over to pump out the oil and get
it started but once it was and burned all the oil out it ran like a
charm.

You shoulda seen the smoke cloud.

REMOVE the NOCRAP in my address to reply.

 

A friend of my dads had a lean burn system car and I am almost certain
that he bought a kit from crysler to convert it over.
REMOVE the NOCRAP in my address to reply.

 

If you use the 4 pin module system instead of the 5 pin, you only use
a single balast resistor, which is the roughly 1/2 ohm compensating
resistor. The more trouble prone 5 ohm "auxiliary" resistor is not
used.
The 4 pin module was generally used on the dual pickup distributors
used on Lean Burn engines. The second pickup was the "start" pickup
and provided a fixed delayed spark for starting, IIRC

 

Y'know, Clare, this is not the first time you've piped up with incorrect
factoids, even considering just this thread only. The original poster's
looking for helpful guidance, and guesses at module application (to say
nothing of nonsense doomsaying about camshaft differences that don't
really exist) probably aren't very helpful. Your description of the 2nd
pickup in the dual-pickup distributors is more-or-less accurate, but not
responsive to any question that was asked. You may want to consider
sitting the rest of this one out.

DS

 

Dan - the information I have from 2 industry sources, states the
single pickup system uses the dual resistor. It also states the dual
pickup system is GENERALLY used on Lean Burn systems, and shows the 4
pin module used on the dual pickup system. The 5 ohm Auxiliary
resistor is shown connected to pin 3 of the module. on the 5 pin
module used as a single pickup system. The .5 ohm compensating
resistor is in series with the coil, and bypassed by the start
position of the switch, or the starter bypass of the starter relay,
depending on the vehicle.
The dual pickup, 4 pin module, does not have pin 3, or the Auxiliary
resistor. The .5 ohm compensating resistor is used identically on both
systems. On some systems the compensating resistor is 1.2 ohms on the
dual pickup 4 pin systems.

So where am I wrong on this one Dan??

By the way, Chrysler used a whole pile of different resistors over the
years - at least 3 different single ones between 72 and 94, as well
as, IIRC two different dual resistors. I know one had the resistors
"potted" and the other had at least one of the resistors open to the
back. - I BELIEVE one superceded the other in an attempt to solve the
problem, but at one point the local dealers carried both under
different part numbers for different applications.
And this does not include all the "captive import" Rootes and Mitsu
stuff.

As far as the camshafts are concerned, I've been involved with
conversions done both ways, and the conversions where the camshaft was
also changed were, in my opinion, more successful. We got better idle,
and more low end torque with the early camshaft than we did with the
late cam, either leanburned or carbed. YMMV. It was my observation
that the smoother idling engine also gave better mileage IN TOWN. No
idea if there was any difference in highway mileage or high end
performance. Mileage was poorer without lean burn either way, but
driveability was maderately improved.

Same experience when removing V V carbs on Fords and replacing with a
standard carb. The conversion worked a lot better with the cam from a
non V V engine.

Myself, I'd just leave the lean burn alone as long as it functions
properly, and put the modified EGR delay on if part throttle surge was
a problem.

Bolt a second double ballast on the firewall for the inevitable
resistor failure on vehcles so equipped.. That's what I've done with
all my old Mopars over the years.

 

Your alleged "industry sources", then, do not match what exists in the
real world. In a case like this, what's actually under the hoods trumps
whatever your "industry sources" have to say on the subject. (Also, why
are you being coy here? This isn't Watergate, y'know, it's car repair. Go
ahead and say where you read or heard what you read or heard.)

Not really, no, they didn't. Unless you count trivial construction
differences over the years as "differences". I don't, since your "whole
pile" of "different" resistors all fit into one of three
interchangeability groups.

This is a manufacturing difference. Go get an Echlin resistor; it's
potted. Go get a Standard; it's not. Both kinds work fine.

That's good 'cause we're not talking about Rootes or Mitsu stuff.

This is a very, very different claim than your original, which was an
assertion that they changed the camshaft profile for specific use on
engines equipped with Lean BUrn (which they did not) and that a lean burn
removal without a camshaft swap would be unsuccessful (which is wrong).

When that's the case, it's best to say so, or just simply say nothing.

We're not discussing FOrds here.

DS

 

past I had a 1968 Scout 800 with a 392ci V8 and it had been converted to

Once you understand how the CDI works you *will* want one!

Yeah.. but point wear, while important, is only part of it. I keep
very close track of my vehicles with log books, entries for every tank
of gas and replaced light bulbs, etc. I could actually *see* the mpg
improvement when I went to CDI. Now, this was a long time ago, the
more mdern systems I have now don't need it. The CDI will start the
car quicker, allow use of a wider plug gap, will allow smooth lugging
beyond what you would think possible. It is a GOOD thing.
Interestingly, I also saw a significant increase in mpg, and rpm
ability when I went to Bosch Plus-4 plugs. Worth the money in my
estimation. I drive a pumped-up Suzuki Samurai 1300, built for less
slow and more off-road ability. Lots of engine mods, suspension,
gearing, etc.

Hear! Hear! Well said!

The vacuum advance (and also retard if I am remembering correctly) may
be very different from non-lean-burn engines. I'd be careful there, I
like the idea of replacing the dang thing or at least the parts that
give the vacuum advance curve. Note that the lean-burn concept
depends on extremely wide spark advance/retard changes as well as wide
swings in fuel mixture.

I assume you have a O2 sensor on there? Don't take it out, it is a
valuable tool. I think you will have to put the lean-burn carb on the
shelf unless you can find out a lot about it. Like what kinda mixture
it defaults to w/o the computer (it does use a computer, right?).
Guess you could monitor it with the O2 sensor. So, if you put a
replacement carb on there, check the mixture via the O2 sensor. Use a
quality (high impedance) voltmeter, multimeter, etc, and note that a
voltage of about .47v (IIRC) is stochiometric. .6v is about right for
max power, .35 - .4 for lean cruise, I think those are close anyway.
Drive the car, warmed up, and monitor the O2 sensor under different
conditions. Should get leaner on cruise, richer under full throttle.
Should hover around.4v - .5v for medium speed cruise. Tune idle and
pilot for off-idle performance and smooth idle.

Other sites have charts showing the O2 sensor curve, voltage vs
mixture. It isn't a straight line.

Not that I know a dang thing about it, I was just googling to find
YOU!

In a previous post somewhere else, I believe you said you had a Geo
convertible LSi? Are you the right guy? If so.. please email me if
you have a few minutes to answer some questions for me. I am
interested in getting one. (Getting a Geo, not a question!

my addy is:
gab(17-1) AT Ess Bee See global Dot Net (do the arithmetic!)

thanks,
GeoB

 

My Police package VIN "S" Diplomat used a dual pickup distributor, dual
ballast, 4 bbl carb and NO ignition module. How, you ask? The ignition
module was part of the engine control module which was mounted on the
driver's kick panel.

My Diplomat that came stock with a 4 bbl Rochestor (sp?) feedback carb,
ECM mounted inside the vehicle, roller cam, and more ground straps then
I have ever seen.

 

Did the cop cars have a EGR valve? Or less EGR flow?

?? I thought '73 was the first year. ?

But carry a spare ballast resistor, the half ohm resistor goes out
about every 100K miles, I never heard of the 5 ohm one failing.
(This is a dual resistor block, kids. Some orange or chrome
boxes don't need the 5 ohm half.)

To original poster:
Points aren't bad on a front distributor, but on a rear distributor
electronic ignition can save a lot of work.
You almost have to set up scaffolding over the car but under the open
hood.

I wish they wouldn't even make those coils.
Hmm, I think Rambler used them around the late '50s, I used to hear
that they didn't work well.

 

VERY different engine configuration. 4bbl carburetor instead of 2bbl,
entirely different EGR system, and numerous other differences.

'73 was the year Chrysler's electronic ignition system became standard
equipment on all Chrysler-built vehicles. '71 was the first year it was
offered as optional equipment.

Yep, a good idea. My Chrysler products each have one in the glovebox. I've
never been caught needing it, perhaps for that reason.

DS

 

OK, both Mitchel's and Motors manuals - plus Chiltons - as well as a
Napa - Echlin application guide.

Yup - some ar half ohm, some are 1 and a half ohm on the singles.
There was something about some being positive co-efficient and some
negative too, but I can't remember the details. Some you could switch
one way without any problems, but could run into problems if you went
the other way. It's been a long time, so I do not remember the
details.

I stated not changing the cam makes for a conversion that does not
work right. Not that it doesn't work. I consider working "right" to be
working like the vehicle that came with a standard carb and
distributor - a "pre emissions" vehicle. If you are going to the work
of pulling off the emissions crap to make it run better, may as well
go all the way. Usually by the time someone got sick enough of it to
make the switch a new timing chain was a good idea already anyway, so
not a lot of extra work to replace the cap - particularly if you take
the manifold off to clean up the manifold heat crossover. If you don't
do that, there's a good chance you'll be in trouble anyways if you
live in a cold climate area because a cold manifold makes for
driveability and economy problems too.

 

Gee, *there's* a collection of reliable sources...

Generally accurate, but as with all weatherlies, there are errors. It is
frequently the case that one data company supplies the whole aftermarket,
which is why a great many errors are present across a great many
aftermarket info sources.

And I note that none of your "industry sources" included the bit of
industry that actually built the car...

Let's count together:

1) 0.5-ohm single
2) 1.5-ohm single
3) 5.0/1.5-ohm double

That's three.

In the automotive world at large, there are different varieties of ballast
resistance. However, one of the details you're not remembering is that
this is irrelevant to the discussion at hand, which is of ONE MAKER's
cars. There are no "positive coefficient vs. negative coefficient"
resistor questions on Chrysler products.

And that's fine, but then you do a disservice when you make assertions on
the subject not prefaced by "As I recall" or "I think".

And you've been refuted by people who've done a no-cam-swap conversion and
had it work right. Perhaps you did something wrong.

DS

 

Yep. The emitter resistor was moved internal to the module itself.

Uhhh...Not even in the right city, let alone in the right ballpark.

On Lean Burn engines, there IS no separate module, either 4-pin or
5-pin. Ignition amplification is built into the Lean-Burn module itself.

That's the whole reason you have to go out and GET a module, GET a
correct distributor, and GET the 4/5-pin wiring harness connector when
you get RID of Lean-Burn!!!!!

 

Pretty much the way ALL "Lean Burn" (note that Chrysler quit calling it
that around 1980) cars worked without an ignition module. Except the
2-bbl versions mounted the computer on the side of the air cleaner housing.

Must have been an 85 or later.

Ah, must've been an 87 or later.

and more ground straps then

Nah, I've seen other Mopars with the 100A alternator and police package

 

Ridiculous. The dual-pickup distributor was used on Lean-Burn engines,
which DID NOT EVEN HAVE a separate ignition module. Yes it is true that
Lean Burn cars ONLY used a single ballast resistor, but the converse is
NOT true. Check an '83 D-150 pickup with a 318 for example: Does not
have Lean-Burn, DOES have a 4-pin ignition module, DOES have a SINGLE
pickup distributor, has a single ballast resistor.

Horse turds. Lean Burn appeared in '75, but '71-73 vehicles are
defintely NOT "pre-emissions." They have OSAC valves, they have PCV,
they have EGR, they have fuel-vapor recovery. Even '65 vehicles have
PCV, so they aren't (strictly speaking) "pre-emissions" either.

Please, by all means, TELL me the differences in valve lift, duration,
lobe separation, and centerline between a 1973 318 cam (non-lean-burn)
and a 1983 318 cam. I'll wait. It'll be a long dang wait, cuz you won't
find any, but I will wait.

 

It was an 85 and it had the 114 amp alternator (big sucker too)

 

The dual ones were 5 ohm and half ohm, the half ohm being the half
that goes bad.

I think Mom's '79 Horizon was a one ohm, never replaced it.

I put '73 ignition in my '77 400. Worked great. Yes, the ELB is a
milder cam, still good to eliminate the ELB.
It was worse working than the ELB-2 of '79+.