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.

Reply to
Steve
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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.

Reply to
Len

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.

Reply to
Len

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

Reply to
clare

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

Reply to
Daniel J. Stern

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.

Reply to
clare

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

Reply to
Daniel J. Stern

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

Reply to
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.

Reply to
Death

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.

Reply to
clemslay

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

Reply to
Daniel J. Stern

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.

Reply to
clare

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

Reply to
Daniel J. Stern

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!!!!!

Reply to
Steve

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 :-)

Reply to
Steve

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.

Reply to
Steve

Steve wrote in news: snipped-for-privacy@texas.net:

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

Reply to
Death

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+.

Reply to
clemslay

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