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Thread: switching to 3.8l coils $8B

  1. #1
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    switching to 3.8l coils $8B

    Hey everyone.

    The stock Quad-4 coils r getting hard to find so thought I would try a couple 3.8l coils. I hooked em up and they work but the idle is high 1200rpm and its pulling the idle timing down from 17 to 10. it has a code35 Idle Improper but was already there and the light is normally off with the red dot by code 35 in the list. now the CES light is mostly on. Is there anything I can change to get these coils to work like latency in $0D? Or maybe they are not compatible with the 8707 ecm? Seems like the timing is high across the rpm range.

    Any suggestions would b greatly appreciated

  2. #2
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    Hello,

    I switched a Q4 to DIS style coils several years ago by using MSD coil adapters. It worked great and solved an issue that involved one coil repeatedly failing. I didn't change the tuning at all.

    Have you looked for signs of a vacuum leak or IAC issue? Is that IAC working?

    do you have tools to read and program chips? You can find 3.8 /3800 coil latency values in a calibration from one of those engines. Transfer them to your 2.3 calibration.

  3. #3
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    Quote Originally Posted by 1project2many View Post
    Hello,

    I switched a Q4 to DIS style coils several years ago by using MSD coil adapters. It worked great and solved an issue that involved one coil repeatedly failing. I didn't change the tuning at all.

    Have you looked for signs of a vacuum leak or IAC issue? Is that IAC working?

    do you have tools to read and program chips? You can find 3.8 /3800 coil latency values in a calibration from one of those engines. Transfer them to your 2.3 calibration.

    Ok so I picked the one bad module out of several. Changed it this morning and that fixed the issue. I looked for the latency scaler and did not find anything labeled "latecy" in the bin. The bin im using, ANMS, is not as defined as the low output anmp so it may not b there. ill have to look in the anmp bin for the latency. I did look at $5B supercharged but no latency there either. all good, i took car of the rare coil issue and the stupid plastic spark distribution cab.

    Thank u!!

  4. #4
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    Isn't that the way?

    Which coils are you using? The 86 turbo Buick 1227148 lists a single value for spark latency.

    $0D which is equal to .013 ms.

    HTH

  5. #5
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    Ha yea Im not sure the exact model but I found a chart that said those coils were used from late 80's to mid late 2000's wasn't boosted in any way. i just looked at the supercharged bin cuz it was the first one I could find that may have those coils. I have a dozen or more from throwing away a car every now and again. maybe this weekend I can compare some more stuff but I gotta figure out that high idle thing, now its idleing 14-1500 while rolling clutch in. hoping i cut the o-ring on the idle valve or ill b at pull a part tomorrow, cant find one local and not sure I have another that fits this offset bolt hole..... The engine seems like its had a couple degree timing added with these coils, knocks a 4000 heavy throttle. Thought I would try dropping the whole map 1* until I can concentrate on it see what happens.
    Most common thing i see those coils on is a buick lasabre front wheel drive 3.8l. Chart said those coils were used on almost all the DIS 4 and 60 and 90* v6. I found the chart on the internet sooo Im not claiming 100% true
    Last edited by BigBanks78; 11-11-2023 at 05:52 AM.

  6. #6
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    ok I looked at the other bin, they r the same as far as i can tell. Same as in # of pid's i guess.. I slept sense then. I lowered the iac position temp offset vs cool temp and it responded in kind so maybe I need to adjust those a bit?? It's a HO 2.3, I tried to keep the engine stock so I didn't have to change much in the bin but I ported a small exhaust port head to a large (Ive cracked a couple) and cleaned up the rest and used the stock 4-2-1 LO header, its steal tube, pretty cool sound. Just left it after 9 months of cobbling together parts. Stuff was lil hard to find. I plan to make a long tube 4-1 header, heard they worked well with the big cams but it runs pretty freaking good, at the right outside temp. I also lowered all the idle, Main and PE spark tables 1* and that seemed bring the power back, Im going to lower them another in a day or 2 of driving. the knock is gone as well.
    Geez didnt ask if i need to Change the IAC tables at all, if that would b normal? I did look everything over, didnt find any air leaks

    Hey I appreciate it and the site :)

  7. #7
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    Oh and no latency anything. Maybe change spark bias table instead of the ones I did? Im feeling my way thru the dark on a lot of the bin.
    Last edited by BigBanks78; 11-14-2023 at 10:01 AM.

  8. #8
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    Chart said those coils were used on almost all the DIS 4 and 60 and 90* v6.
    Latency for those coils is available. Shows in one calibration as 153 ms or $000A. What calibration are you using? I may be able to match code to find the latency value.

  9. #9
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    I cant find a calibration table for Latency at all in $8B. I used the search tool, nothing and looked down the list, didnt c it. Is there another name for it? Im using ANMS HO 5speed

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    I just seen this,( Low fan anticipate steps set at 5.) High fan in this bin is f7-coolant over heat light and is set at 0.00 anticipate steps. so when I set the low fan and stop useing the high fan as a fan, it now idles high as long as the fan is on and i just put a 195 thremo from a 180 and havent changed the fan temp settings yet. I set the low fan at 0.00 steps and will c what happens.

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    I cant find a calibration table for Latency at all in $8B. I used the search tool, nothing and looked down the list, didnt c it. Is there another name for it?
    It's probably not in the definition you're using. I have a copy of ANMS. I'll see if I can find it.

    I set the low fan at 0.00 steps and will c what happens.
    That might work. It doesn't seem like the coil change alone can cause this, but stranger things have happened.

  12. #12
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    Yea I dont think its the coils either, settings may need to b adjusted a tad but not the issue. I checked everything again after lowering the steps for the fan cuz that did not work, so I adjusted the throttle plate closing it until the idle speed and timing adjustment in the data stream were in the correct range. now the only time the idle isnt correct the tps reads .39% which is not often and ive never seen the tps read like that so I was going to adjust that, I think the bolt holes come slotted for adjustment. Its been to cold to find motivation for that step :). The terminology always gets me, the "definition" Is the XDF correct? If so how complicated is it to add?

  13. #13
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    Technically there are two definitions. The XDF is used for tuning, for changing what's in the .bin file. There's also an ADX which is a definition for reading data while the vehicle is running.

    I didn't think those tps were slotted. They're supposed to "auto zero" in code.

  14. #14
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    Yea you're correct, that one is not adjustable. I replaced it, I seen the throttle land on 1.??% after an intermittent .39%.... Not sure if that really changed much for the idle. I did open the sparkplug gap a bit, I changed the plugs when I changed the coils

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    I'll have to drive it a bit more to see if the idle stays down. seems like i have to drive this thing for a week or 2 before it learns the change or does whatever it does not to do odd things. I put the timing back where it was to begin with, it got worse gas milage and was kinda slugish, after that ve was pretty lean but it got colder outside so i adjusted that, will c what happens.... I have the worse time with outside temp change. I got u on the Definition. I downloaded at least 2 different or what i thought were different $8B XDF's When I have more time I'll look.

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