Correct FCD Hookup For 84

[jonboyb]

I remember some form of controversy regarding the HKS FCD hookup on early models. The thread (for flattys) seems to be old enough to not be on the forum anymore. Does anyone have a correct diagram, or can anyone confirm that the one on the HKS website does indeed work?

 

With the "G" wheel turbo on the 84 I hit fuel cut at like sub-8 psi :mad: Have to ease into it all the time (especially now that it's cold) to avoid fuel cut.....no fun. Apparently the increased flow even at stock boost levels is enough to throw it into cut.

Edited December 28, 2010 by jonboyb

[psu_Crash]

My Old School FCD on my '86

http://img149.imageshack.us/img149/7769/hksfcd.jpg

 

Was connected under the driver seat wiring as shown below. This is just where it was spliced in. Power and ground are not shown but those are easy enough to find. I hope this helps!

http://img172.imageshack.us/img172/5967/fcdhookup.jpg

[jonboyb]

Under the seat.....WTH!

[psu_Crash]

Under the seat.....WTH!

 

HAHA! Same thing I thought when I found it! It was already installed when I bought the car. It did work though. I never took the time to see what the wire was that it spliced into. Maybe I'll take a look now.

 

Edit: Hmm ... looking at the wiring diagram that wire seems to go to the defogger relay. Maybe you should ignore my advice ...

From the schematic I would guess it should be hooked into the yellow wire that runs from the pressure sensor to your ECU. I'm sure someone else will chime in.

 

P.S. If you don't already have one, get an aftermarket boost gauge ASAP

Edited December 28, 2010 by psu_Crash

[Komeuppance]

On an 86 flatty, the pressure sensor output is connected to pin A17 at the ECU. On the 86 flatty, there are only 17 pins available on the ECU A connector. This is where we installed a diode to limit the signal, and prevent fuel cut. I'm guessing it the same on 84's.

 

The pressure sensor wiring is connected through the wiper harness, not the engine control harness, and that goes to the ETACS under the seat... probably why it's connected there. But I didn't know that the ETACS needs a pressure solenoid reference... hmmm... EDIT: maybe for the stock boost gauge.

 

-Robert

[jonboyb]

I'm definantly going to do some research on this one.......that would be hella sweet if I can wire the FCD under the seat and not have to butcher the wiring near the ECU. No room to work in that kickpanel (nor do I like having to cut what little wire is available near the ECU)

[MikeMeyerhoff]

Going from memory, the 84 and 86 ecu connections were different.

 

I did a FCD on my Kieser 84 by following the directions for the 86. But the exact wires at the ECU connection were different so I had to compare both year FSMs to get it right. I did mine directly inside the ECU by soldering onto the socket itself before it got to the board.

[Metric-man]

Going from memory, the 84 and 86 ecu connections were different.

 

I did a FCD on my Kieser 84 by following the directions for the 86. But the exact wires at the ECU connection were different so I had to compare both year FSMs to get it right. I did mine directly inside the ECU by soldering onto the socket itself before it got to the board.

 

Mike is correct A17 is different on 84 85 but the problem might be the design change in [88.5 (intercooled) /86] those years were the start of the High Attitude/ cold start provision,

and A17 A4 on the [85.5 (intercooled) /86],

is there is a intake temperature "A" and an intake temperature "B" sensors

 

In 84/85 there is only one, an intake temperature "A" which in located at ECU terminal A4.

 

IF my memory serves me, some one posted that they had discovered the FCD only acted as a resistor,

and if the correct (radioshack) resistor was placed in line between the sensor on the ECU, you would be able to achieve the same purpose.

 

here is an article from Autospeed that is more complicated, but does the same thing

use "air fuel mod" in an internet search.

Edited December 29, 2010 by starion_cult

[Komeuppance]

Intercooled ECU's are the same connections, both 85.5 and 86IC. Yes, they had a second air intake sensor, "B". The 86 (flatty) non intercooled ECU's did not, and were a smaller pin configuration than the intercooled models.

 

86(flatty) non IC ECU's use pin A4 as well for the intake air temp sensor "A".

 

A 4.3v zener diode will limit voltage from the pressure sensor to prevent fuel cut.

 

-Robert

[jonboyb]

I already have an FCD laying around so not an issue. I didn't have time to pull out my 84' FSM last night to go through the wiring, but if everything MAP related is indeed passing through the ETACS harness under the drivers seat (ie. the MAP signal wire runs there prior to going to the ECU) that's a much better alternative for me to use. I can pull the seat out and solder easily versus trying to do it correctly under the dash. Soldering uphill in tight spaces SUCKS Edited December 29, 2010 by jonboyb

[Metric-man]

Intercooled ECU's are the same connections, both 85.5 and 86IC. Yes, they had a second air intake sensor, "B". The 86 (flatty) non intercooled ECU's did not, and were a smaller pin configuration than the intercooled models.

 

86(flatty) non IC ECU's use pin A4 as well for the intake air temp sensor "A".

 

A 4.3v zener diode will limit voltage from the pressure sensor to prevent fuel cut.

 

-Robert

 

Oh Robert (%&*^)

 

85.5 intercooled and 86 non intercooled are *(not) the same. that's why they are in parenthesis,

I did not create the whole post from memory.

I used a FSM.

 

I notice Robert your always racing, to post an answer and do not always write correct information.

 

So maybe what you wanted to write is that you were incorrect (at first) on the location for the FCD to be used ?

A4 not A17 ? (or maybe you just need a revised edition for your FSM ?)

 

On an 86 flatty, the pressure sensor output is connected to pin A17 at the ECU...

 

I'm glad jonboyb has enough sense to look it up himself.

I already have an FCD laying around so not an issue. I didn't have time to pull out my 84' FSM last night to go through the wiring, but if everything MAP related is indeed passing through the ETACS harness under the drivers seat (ie. the MAP signal wire runs there prior to going to the ECU) that's a much better alternative for me to use. I can pull the seat out and solder easily versus trying to do it correctly under the dash. Soldering uphill in tight spaces SUCKS

 

jonboyb here is the only instructions in jpg format I could acquire (they are generic),

for the FCD if you do not already have one.

 

If you need more information maybe someone can post,

the Starion ECU pin outs that came with the full copy of the FCD,

if not I'll see if I can dig out my (paper) copy and post it up.

 

The whole write up has already been done it is in the FAQ

(FCD write up thread)

Here is a link to the

ECU Pin out diagram from the HKS instruction manual

 

 

Post back please to let others know if it worked out for you , using the etacs location..

 

*edit

Perhaps what you wanted to read is correct?? You're racing before you read what others post, or just ignoring it, I noticed.

 

-Robert

Edited December 30, 2010 by starion_cult

[Komeuppance]

Oh Robert (%&*^)

 

85.5 intercooled and 86 non intercooled are the same that's why they are in parenthesis,

I did not create the whole post from memory.

I used a FSM.

 

I notice Robert your always racing, to post an answer and do not always write correct information.

 

So maybe what you wanted to write is that you were incorrect (at first) on the location for the FCD to be used ?

A4 not A17 ? (or maybe you just need a revised edition for your FSM ?)

LOL... what?? So, what pin does your 85.5(IC) manual state for intake air temperature "B"?? Do you have the 85.5 supplement?? Post back and let me know so we can see if 85.5 intercooled and 86 non intercooled ECU's are the same.

 

Like I stated correctly, on an 86(flatty) A4 is an intake temp sensor signal ("A"), what does that have to do with the boost pressure signal, A17?? 86(intercooled) is different.

 

I was confirming that in the non IC 86's pin A4 is the same as you said the 85's was, so I was agreeing with you. I also stated the zener diode to agree with you about "the resistor you heard about".

 

Perhaps what you wanted to read is correct?? You're racing before you read what others post, or just ignoring it, I noticed.

 

-Robert

[Metric-man]

LOL... what?? So, what pin does your 85.5(IC) manual state for intake air temperature "B"?? Do you have the 85.5 supplement?? Post back and let me know so we can see if 85.5 intercooled and 86 non intercooled ECU's are the same.

 

Like I stated correctly, on an 86(flatty) A4 is an intake temp sensor signal ("A"), what does that have to do with the boost pressure signal, A17?? 86(intercooled) is different.

 

I was confirming that in the non IC 86's pin A4 is the same as you said the 85's was, so I was agreeing with you. I also stated the zener diode to agree with you about "the resistor you heard about".

 

Perhaps what you wanted to read is correct?? You're racing before you read what others post, or just ignoring it, I noticed.

 

-Robert

 

I made a typo, I wrote A17 twice.

 

Yes Robert, I see your confusion.

 

No Robert intercooled and non intercooled ECU are not the same.

 

HKS FCD will work up-to 1986 vehicles intercooled and non intercooled,

I was just confirming the location on the ECU pin-out. (A4) because you mentioned you thought it was (A17)

 

Yes Robert I do believe you know what your talking about most the time, when it referring to Starion/ Conquests.

 

My reference material is the:

 

Chrysler Corporation ECI-TURBO system operating and testing 1984-1986

 

That was generously PDF formatted by "Buzzkill" and electronically distributed (free to use) to other members.

The original copy for formatting was digitally scanned and supplied by "Metric-man" .

Edited December 29, 2010 by starion_cult

[Komeuppance]

LOL!! Yep a "typo". That's funny, I don't need to go back and edit my posts to make correct information, typo or not.

 

Oh hey look, I have the same information without Metric's involvement, plus I read it correctly. And I uploaded it to my site for all to share:

 

http://home.comcast.net/~DriftAbility/images/Komeuppance/19841985ECU.jpg

http://home.comcast.net/~DriftAbility/images/Komeuppance/19841985ECU.jpg

 

http://home.comcast.net/~DriftAbility/images/Komeuppance/1986NOICECU.jpg

http://home.comcast.net/~DriftAbility/images/Komeuppance/1986NOICECU.jpg

 

http://home.comcast.net/~DriftAbility/images/Komeuppance/19855ECU.jpg 1985.5 ECU

 

http://home.comcast.net/~DriftAbility/images/Komeuppance/1986ICECU.jpg 1986IC ECU

 

Looks like I was right, same pinouts on 84/85 as 86's(non intercooled). Also, 85.5(ic) are the same as 86(ic).

 

-Robert

[Coke]

 

HKS FCD will work up-to 1986 vehicles intercooled and non intercooled,

 

 

 

I'm pretty sure it will work on 1987 model years as well. You don't HAVE TO run an 88/89 ECU if you wanna turn up the boost. It's just easier to.

[Chad]

the whole reason for the 88/89 swap into the 87 box is because of the 87's fuel cut, which can not be gotten arround with a FCD.

[shift1313]

For what its worth awhile back i tried the resistor trick with various values, even used a pot, on the air temp line from the MAS with no luck. I did this right at the source and not inside the car. My 84 would hit 10psi on the stock turbo non IC without any modifications. After 10(with a real gauge) it would start to buck. With an IC i was lucky to hit 6 psi regardless of resistor configuration. Hopefully I either did something wrong or there is a little bit more to the FCD that will work on your 84.

 

Also for what its worth i believe there were 6 different engine harness configurations for the 84/85 cars depending on a few things. the ECU pin-outs were the same but i believe the etac setups were different. Things like digital dash and that voice:) Obviously if you are going straight to the ECU with the FCD this isnt a problem.

 

good luck and let us know how it works out.

[StarquestRescue]

For what its worth awhile back i tried the resistor trick with various values, even used a pot, on the air temp line from the MAS with no luck. I did this right at the source and not inside the car. My 84 would hit 10psi on the stock turbo non IC without any modifications. After 10(with a real gauge) it would start to buck. With an IC i was lucky to hit 6 psi regardless of resistor configuration. Hopefully I either did something wrong or there is a little bit more to the FCD that will work on your 84.

 

Also for what its worth i believe there were 6 different engine harness configurations for the 84/85 cars depending on a few things. the ECU pin-outs were the same but i believe the etac setups were different. Things like digital dash and that voice:) Obviously if you are going straight to the ECU with the FCD this isnt a problem.

 

good luck and let us know how it works out.

Did you mean to say pressure sensor line?

 

I do not think the pressure sensor wire to the ecu goes any where near the etacks. I did seperate an 85.5 ecu/pressure sensor harness from the dash harness years ago and do not recall any thing heading back there.

Edited January 2, 2011 by StarquestRescue

[Komeuppance]

I do not think the pressure sensor wire to the ecu goes any where near the etacks. I did seperate an 85.5 ecu/pressure sensor harness from the dash harness years ago and do not recall any thing heading back there.

 

Good to know... I'm still perplexed as to why Psu_Crash said his worked, when wired to pin 4 on the ETACS. According to the FSM, that is indeed the defogger relay timer output, haha. Fuel Cut Defogger.

 

-Robert

[psu_Crash]

Good to know... I'm still perplexed as to why Psu_Crash said his worked, when wired to pin 4 on the ETACS. According to the FSM, that is indeed the defogger relay timer output, haha. Fuel Cut Defogger.

 

-Robert

 

I have no idea how it worked, but I used to pull the old turbo to 18psi without a problem (for a while) For all I know that wire is rerouted under the dash somewhere. The previous owner wired a lot of things into my car with thrown spaghetti fashion. The harness behind my glovebox and driver's foot well is an absolute nightmare with splices and wire jumped everywhere. Most of it for an old Viper security system that is no longer there.

[shift1313]

Did you mean to say pressure sensor line?

 

I do not think the pressure sensor wire to the ecu goes any where near the etacks. I did seperate an 85.5 ecu/pressure sensor harness from the dash harness years ago and do not recall any thing heading back there.

 

 

Nope, i tried to trick the ecu to thinking the air temp was colder than it actually was so it would account for a denser mix and dump more fuel. I dont know how any of that ties into the etacs. I mentioned the different harness thing because someone mentioned wiring the fcd into the etacs. I messed with inputs right to the ecu but on the engine bay side.

[Metric-man]

Nope, i tried to trick the ecu to thinking the air temp was colder than it actually was so it would account for a denser mix and dump more fuel. I dont know how any of that ties into the etacs. I mentioned the different harness thing because someone mentioned wiring the fcd into the etacs. I messed with inputs right to the ecu but on the engine bay side.

 

 

http://autospeed.com/cms/title_DIY-Modification-of-Car-Electronic-Systems-Part-2/A_109134/article.html

[Chad]

http://autospeed.com/cms/title_DIY-Modification-of-Car-Electronic-Systems-Part-2/A_109134/article.html

 

Interesting article, just don't use cheap pots, those tend to have poor consistancy, and are subject to spikes and dips due to the mechanical nature of their design. I use them for fine tuning delicate signals at work, they can be trickey sometimes after they have been used for a while. Sometimes you can change their output just by tapping on them.

[shift1313]

http://autospeed.com/cms/title_DIY-Modification-of-Car-Electronic-Systems-Part-2/A_109134/article.html

 

 

very interesting article. When i was trying to trick the ecu i tried a few different value resistors and then a pot. I still wasnt happy with the results in my specific case.