User Tag List

Thanks Thanks:  0
Likes Likes:  0
Results 1 to 14 of 14
  1. #1
    Join Date
    Jan 2020
    Location
    Pinole, Ca
    Posts
    200
    Thanks (Given)
    6
    Thanks (Received)
    8
    Likes (Given)
    44
    Likes (Received)
    24
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    EXTERNAL Rev Limiters and TPS

    I am totally confused about what came on what and when. I don't have any problem I am trying to solve, I just wanna know.

    The external TPS, Mercury PN 17814a4 its a little black box that has two wire pigtails (one with 2 wires and the other with 3) as well as a vacuum lead. I search the part on mercnet and it shows as a valid part with a description but it doesn't say what motor it ever came on. My brain with no experience tells me that this would be a piece used when they were transitioning from a 3 wire TPS like they had on the early EFI engines to the more modern MAP sensor which determines the throttle position. Am I right that this is a mini computer that translates the MAP vacuum into the same voltage that a 3 wire TPS would have produced? If so, how does that work with 5 wires and how was it hooked up? Also, what ECUs needed this module?

    Second question: what ECU models used an external rev limiter and what happens if one is not installed? Would the engine still run and not have a limit, or does it need it in the circuit to still run?

    Thank for any info you are willing to divulge - J Avery
    8' Yellow Jacket - 25 hp Mariner
    1984 Hst VKing - Bridgeport EFI
    22' Aquasport - 150 SeaPro Fourstroke

    25 hp Merc that runs on ACETONE
    25 hp Merc with OFFSHORE style midsection
    25 hp Merc with dry side pipe
    25 hp Merc with 11" mid and 2.42:1 gears


  2. #2
    Join Date
    Nov 2011
    Location
    Houston, TX
    Posts
    1,096
    Thanks (Given)
    124
    Thanks (Received)
    40
    Likes (Given)
    554
    Likes (Received)
    124
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    I thought the ecu's just went rich to limit the rpm. We had some work done to a Promax ecu to open up the rpm a bit and it was done with the fuel curve, not with a review limiter as I think of them in a car with an msd.
    1990 Shadow bass boat w/ 2.4 200 Merc. Totally resto'd boat and love it!

  3. #3
    Join Date
    Jan 2020
    Location
    Pinole, Ca
    Posts
    200
    Thanks (Given)
    6
    Thanks (Received)
    8
    Likes (Given)
    44
    Likes (Received)
    24
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yes, that is true that it is all done with the fuel curve, and companies like Brucato can adjust that...but merc shows some 2.4 EFI motors as having a "rev limiter" module mounted where the rectifier would sometimes go on top of the PH in the middle of the V...I'm sure SOMEONE reading this knows how that module worked? Mercnet shows that the "2.4 EFI" motors had them, while "ModVP EFI" and "Formula 1" motors did not. Even though the ModVP EFI was 2.4L and the early Formula 1 were 2.0L motors the were near identical to the 2.4 motors (if I'm not mistaken)...

    So what even was the difference between the 2.4 EFI and the ModVP EFI 2.4 sold during the same time period? They have overlapping serial number ranges so they were sold at the same time, but I was not around back when they were for sale new... As I understand they were both offered in Bridgeport and Ovalport...so what was the difference?

    The rev limiter I am talking about is merc PN 86926A 2 or A 4
    8' Yellow Jacket - 25 hp Mariner
    1984 Hst VKing - Bridgeport EFI
    22' Aquasport - 150 SeaPro Fourstroke

    25 hp Merc that runs on ACETONE
    25 hp Merc with OFFSHORE style midsection
    25 hp Merc with dry side pipe
    25 hp Merc with 11" mid and 2.42:1 gears


  4. #4
    Join Date
    Nov 2011
    Location
    Houston, TX
    Posts
    1,096
    Thanks (Given)
    124
    Thanks (Received)
    40
    Likes (Given)
    554
    Likes (Received)
    124
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by 25two.stroke View Post
    Yes, that is true that it is all done with the fuel curve, and companies like Brucato can adjust that...but merc shows some 2.4 EFI motors as having a "rev limiter" module mounted where the rectifier would sometimes go on top of the PH in the middle of the V...I'm sure SOMEONE reading this knows how that module worked? Mercnet shows that the "2.4 EFI" motors had them, while "ModVP EFI" and "Formula 1" motors did not. Even though the ModVP EFI was 2.4L and the early Formula 1 were 2.0L motors the were near identical to the 2.4 motors (if I'm not mistaken)...

    So what even was the difference between the 2.4 EFI and the ModVP EFI 2.4 sold during the same time period? They have overlapping serial number ranges so they were sold at the same time, but I was not around back when they were for sale new... As I understand they were both offered in Bridgeport and Ovalport...so what was the difference?

    The rev limiter I am talking about is merc PN 86926A 2 or A 4
    I think you might be talking about the "black boxes" that we always remove. One was for timing retard at WOT and the other is an idle stabilizer. Both work on timing.

    https://www.screamandfly.com/showthr...Control-Module
    1990 Shadow bass boat w/ 2.4 200 Merc. Totally resto'd boat and love it!

  5. #5
    Join Date
    Jan 2020
    Location
    Pinole, Ca
    Posts
    200
    Thanks (Given)
    6
    Thanks (Received)
    8
    Likes (Given)
    44
    Likes (Received)
    24
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Ok, so that is one of the disposable parts. I always ditch the idle stabilizer box cause they only cause trouble...so that revlimiter was the same thing just for the top end?
    8' Yellow Jacket - 25 hp Mariner
    1984 Hst VKing - Bridgeport EFI
    22' Aquasport - 150 SeaPro Fourstroke

    25 hp Merc that runs on ACETONE
    25 hp Merc with OFFSHORE style midsection
    25 hp Merc with dry side pipe
    25 hp Merc with 11" mid and 2.42:1 gears


  6. #6
    Join Date
    Nov 2011
    Location
    Houston, TX
    Posts
    1,096
    Thanks (Given)
    124
    Thanks (Received)
    40
    Likes (Given)
    554
    Likes (Received)
    124
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Yeah, ditch both of the boxes. The retard box can skitz out and advance timing on top and melt you down with no warning
    1990 Shadow bass boat w/ 2.4 200 Merc. Totally resto'd boat and love it!

  7. #7
    Join Date
    Jan 2020
    Location
    Pinole, Ca
    Posts
    200
    Thanks (Given)
    6
    Thanks (Received)
    8
    Likes (Given)
    44
    Likes (Received)
    24
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Does anyone know why it had a vacuum line running to it?
    8' Yellow Jacket - 25 hp Mariner
    1984 Hst VKing - Bridgeport EFI
    22' Aquasport - 150 SeaPro Fourstroke

    25 hp Merc that runs on ACETONE
    25 hp Merc with OFFSHORE style midsection
    25 hp Merc with dry side pipe
    25 hp Merc with 11" mid and 2.42:1 gears


  8. #8
    Join Date
    Jan 2003
    Location
    aalsmeer
    Posts
    944
    Thanks (Given)
    0
    Thanks (Received)
    42
    Likes (Given)
    3
    Likes (Received)
    59
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    could be this one but in general it,s best to take the KISS principle with mercury engines!
    https://en.wikipedia.org/wiki/KISS_principle
    Attached Files Attached Files
    Last edited by PanRonnie; 12-05-2020 at 04:25 AM.

  9. #9
    Join Date
    Nov 2011
    Location
    Houston, TX
    Posts
    1,096
    Thanks (Given)
    124
    Thanks (Received)
    40
    Likes (Given)
    554
    Likes (Received)
    124
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    On clue on vacuum line. The one I'm reference is electrical wires only.

    Might suggest you buy a factory service manual for it. Or download one.
    1990 Shadow bass boat w/ 2.4 200 Merc. Totally resto'd boat and love it!

  10. #10
    Join Date
    Jan 2020
    Location
    Pinole, Ca
    Posts
    200
    Thanks (Given)
    6
    Thanks (Received)
    8
    Likes (Given)
    44
    Likes (Received)
    24
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I have one. I have pretty much all the mercury books. The EFI section of the mercury 2.4 book is not very good at all.
    8' Yellow Jacket - 25 hp Mariner
    1984 Hst VKing - Bridgeport EFI
    22' Aquasport - 150 SeaPro Fourstroke

    25 hp Merc that runs on ACETONE
    25 hp Merc with OFFSHORE style midsection
    25 hp Merc with dry side pipe
    25 hp Merc with 11" mid and 2.42:1 gears


  11. #11
    Join Date
    Jan 2003
    Location
    aalsmeer
    Posts
    944
    Thanks (Given)
    0
    Thanks (Received)
    42
    Likes (Given)
    3
    Likes (Received)
    59
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Attached Files Attached Files

  12. #12
    Join Date
    Jan 2020
    Location
    Pinole, Ca
    Posts
    200
    Thanks (Given)
    6
    Thanks (Received)
    8
    Likes (Given)
    44
    Likes (Received)
    24
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by PanRonnie View Post
    I looked at those diagrams when you sent before...so it is not a part that must be in the system, but it is basically and idle stabilizer, right?
    8' Yellow Jacket - 25 hp Mariner
    1984 Hst VKing - Bridgeport EFI
    22' Aquasport - 150 SeaPro Fourstroke

    25 hp Merc that runs on ACETONE
    25 hp Merc with OFFSHORE style midsection
    25 hp Merc with dry side pipe
    25 hp Merc with 11" mid and 2.42:1 gears


  13. #13
    Join Date
    Jan 2003
    Location
    aalsmeer
    Posts
    944
    Thanks (Given)
    0
    Thanks (Received)
    42
    Likes (Given)
    3
    Likes (Received)
    59
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    basically none have to be in the system as long as you don,t do offshore racing
    think this one or a version of it would be the limiter you are looking for
    but there is just so much!
    if you are worried about over reving you could install something like this and ground the ignition
    https://www.holley.com/products/nitrous/controllers_and_accessories/controllers/parts/15982NOS

    https://www.summitracing.com/parts/izl-n3211
    https://www.summitracing.com/parts/izl-n3211
    you need a 12 cylinder
    Attached Files Attached Files
    Last edited by PanRonnie; 12-07-2020 at 12:23 PM.

  14. #14
    Join Date
    Jan 2020
    Location
    Pinole, Ca
    Posts
    200
    Thanks (Given)
    6
    Thanks (Received)
    8
    Likes (Given)
    44
    Likes (Received)
    24
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Ok, thanks for the info. Yeah I am not worried about anything really, I just wanted to know. The more rpms I get the better, I am not concerned with limiting them or stabilizing my idle...

    If the engine won't idle right on its own then something else is wrong.
    8' Yellow Jacket - 25 hp Mariner
    1984 Hst VKing - Bridgeport EFI
    22' Aquasport - 150 SeaPro Fourstroke

    25 hp Merc that runs on ACETONE
    25 hp Merc with OFFSHORE style midsection
    25 hp Merc with dry side pipe
    25 hp Merc with 11" mid and 2.42:1 gears


Similar Threads

  1. RH & LH 300 XS DBR L1.3 ECU with 7,000 rpm limiters
    By MDRURY in forum Misc. Parts and Accessories
    Replies: 0
    Last Post: 05-28-2020, 07:47 PM
  2. Rev Limiters
    By dreamerdfl in forum Racer's Hangout
    Replies: 4
    Last Post: 10-24-2014, 04:47 PM
  3. Merc rev limiters
    By David in forum Technical Discussion
    Replies: 1
    Last Post: 12-02-2010, 11:48 PM
  4. Info on Ign limiters...
    By Russ in forum Technical Discussion
    Replies: 4
    Last Post: 04-03-2002, 08:36 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Eddie Marine - Horizontal