Hard start cold Fixed! Changed coil
 

Working on my neighbor's '90 LeSabre. It has the Series I (square) coils.

It has been very hard to start in the cold. Once running, works fine. Starts OK warm. Has stalled a couple of times recently.

My first effort was to remove the throttle body to inspect the AIC pintle and passages. Throttle body was black with soot, no oil. Cleaned it and the MAF, and checked the resistances on the AIC. All OK.

Hard start cold persisted.

Checked coil resistances and got:

6-3........14.5 K ohm

Attachment 70871

2-5.........12.4 K ohm

Attachment 70872

4-1.........open

Attachment 70873

Obviously I've got a bad coil. Can I swap in a series II ICM and coil pack? Will it just bolt and plug in? Or do I need to do something else?

Are those symptoms consistent with a bad coil? Once it starts, it runs normally without any apparent misfiring.

You've got a funny intermittent or high resistance that breaks down under load, allowing current flow.

A Megohmmeter would probably read that open coil fine, but most people can't find those any more.

I'm assuming it's the Magnavox setup? One solid coil with 6 posts and 3 humps? I'd do a Delco2 swap on it and call it good.

Thanks, Bill. I'll pick up a SeriesII coil pack and ICM this AM at the junkyard and let you know how it goes.

Yeah, it has the Magnavox setup, I guess. Three humps on the same cast base. I used the multimeter I got for free with the Actron scan tool. Set it to the 200K ohm range for the readings. Measurements were made cold (30*F). I wonder if it is a break that touches and completes the circuit after it starts to run. That's how it's acting.

For others wanting to try this, I just found this post from jr's3800 searching "coil swap": (Who knew it would be that easy?)

http://www.bonnevilleclub.com/forum/...ight=coil+swap

Bill...the only big thing you need to ensure it that you get the L27 mounting plate to ensure it bolts right up.

So, there is a difference in the ICM mounting setup between the LN3 and the L27?

I'll just pull the magnavox unit and take it with me to make sure the bolt holes line up with the new unit.

You need the plate that goes underneath the ICM from an L27... The series II engines have a diffrent mounting bracket altogether...

When you find the L27, that plate I'm talking about attaches to the bottom of the ICM via the coils, and that plate has 3 bolts in it in the exact same arrangement as the Magnavox module..

Let me know and I can dig up some pics to show you what I'm talking about...

;)

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OK, I think I got it. I need a mounting plate from an L-27. I mount the ICM and coil pack from any Series II to that, then install in the LN3 (?)

Correct.... Dead on the money ;)

Make totally sure you get the coil bolts from the L27 as well... The series I and 2 use diffrent size bolts for the coils even tho the coils are almost identical..

L27 Coil Bolts
Lower ICM bracket with the lower bolts to attach to the alternator bracket

L36-67 series II
ICM
Coils

Hope that helps

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It do. Off to the junkyard!

Let us know how it all goes
;)

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Ahem..there's a mounting plate in that box of goodies sitting about 3 feet to your right. ;)

Thats some of what I was thinking about....lol :D

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Well, bummer! :( At some point, I realized the Buick is not my car to modify. And the yard would not warrant the used L36 coils if I installed them in the LN3 'cuz they had never heard of it, and didn't believe me that it would work. (Could it have been the way I was dressed?) Plus - I would have had to destroy a saleable L-27 coil / ICM setup to get the plate and bolts and was not up for paying for two to get one @ $45/ea

Between $90 with no warranty and $45 with, it was no contest.

So, this swap will have to wait 'til I own an LN3 or the owner is up to trying it at his own risk and expense. (This may happen soon, as I may buy this Buick from him.)

Thanks for the help anyway, guys.

I did test the coils in the yard before pulling the magnavox replacements and got:
10.6, 10.5 and 10.7. Hope this was the cause of the no-start cold.

Will let you know soon.

You need a good U Pull It like we have here in Florida... Cheap I tell ya... Cheap...

I have had a couple of the Magnavox coil packs fail... Not a pretty thing either... Usually its one coil alone that goes bad... I have even replaced the stock ICM with a bran new AC Delco/Magnavox ICM at $175... That was way Before Bonneville Club, and way before the fact that we learned that the Type 2 swap was more than possible... Most don't believe that it will work..

The parts places locally told my friend with the 91 Park Ave that it was not possible... He told them that he believed it was as he rememberd a friend of his doing it to his 91 3800... They told him it was not possible and would not work... I opened my hood and told my friend to look... He said Oh S&*^ thats right you were the one who told me it would work...

The main reason my friend wanted the type 2 is he feels his type one is getting weak.. Even he told me I know the type 2's fire hotter thats why I want one on my car... So he too is looking for a Type 2 for a swap.... If I make it to daytona I'll have to pick one up for him... LOL

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Hard start cold Fixed! Changed coil
 

Well I put in the junkyard coil pack and ICM and it fired up instantly (still 30*F here)
Took the car for a ride and it runs and shifts really well. This LN3 has a better (quicker) throttle response than my L36 or my L67. I doubt it would beat the SSEi in race, but it is so tight off the line, I may just have to buy it! It only has 93K miles on it.

Gonna change the name of the post to help with hard start searches.

Thanks to all for the help.

Re: Hard start cold Fixed! Changed coil
 

I have noticed the same... My LN3 is more responsive than my L36... And it wouldn't win aginst the L36 but that LN3 sure is a torquey little monkey...

I believe that the THM440-T4(4T60) had a converter with less stall than the Newer L27/67/L36... Plus the torque from the LN3 was produced way down, so as soon as you tap the throttle the torque is instant... You should hear it groan around at 50 mph in OD... I love it....LOL

Its may be an older motor, but they are known for their durability and longevity ;)

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Was this responsiveness only after updating the coils?

I did not update the coils.

The updated coils are supposed to improve the performance of the L27 and LN3, but in this case we're discussing the throttle response of the stock LN3. For me, they are really more fun to drive around town because of that quick feel.

:oops: How the heck did I miss 3 posts. Sorry..

Then they are merely more responsive naturally. Thanks