how do i wire a Greddy FCD?

[MR2SW22]

well i got this FCD from the previous owner, but it doesn't have the wiring harness that clips into the end of this unit but i figured i'd just cut the plug off and lengthen the wires a bit to reach the ecu. i'm gonna post a pic of it so you can see what im talking about but it's only 4 wires. i believe the red wire is ecu power, black is ECU ground, and the other two i dunno where they go, i think i read somewhere it goes to the ecu map boost sensor? and the other to rev or speed limit sensor?

[Sang]

Don't bother installing it. Instead of splicing it in, into your harness, just pull the boost reference line off the MAP.

All the Greddy FCD does is eliminate fuel cut, not adjust it. By installing it, all that happens is you got rid of FC entirely, which is exactly what pulling the vacuum line does.

[Ben]

Is the MAP sensor responsible for any other engine functions other than just regulating boost cut? I know the stock boost gauge will not work any more, but is the MAP sensor there only to act as a governor?

[Sang]

Originally Posted by Ben

Is the MAP sensor responsible for any other engine functions other than just regulating boost cut? I know the stock boost gauge will not work any more, but is the MAP sensor there only to act as a governor?

On a gen2, yes. The sensor is not used to control any other engine parameter but FC.

[MR2SW22]

Originally Posted by Sang

On a gen2, yes. The sensor is not used to control any other engine parameter but FC.

well, i met someone at the AZ meet, and i will look for his name, but he said that with that sensor disabled his car ran like crap. currently, mine is idling lower than usual, but i just plugged in the 2nd gen JDM ECUabout 2 weeks ago and changed to the copper NGK plugs that everyone raves about. that's the only things i've changed and im wondering if the idle was off because i plugged the boost sensor, and plug the intake manifold inlet piece that it hooked up too. well i just drove the car and the idle is still lower than usual, but i did notice that the boost kicked in a little faster and harder than it use to, could just be in my mine but im waiting until i get near my home to go WOT and see if i set off the stock boost cut again. Sang, do you think the JDM ecu will have a higher boost cut? cause im running the stock waste gate no BC.

[Sang]

Originally Posted by MR2SW22

well, i met someone at the AZ meet, and i will look for his name, but he said that with that sensor disabled his car ran like crap.

As it should. The ecu still needs the map sensor for a reading. It just doesn't matter whether that reading is atmospheric pressure/vacuum/or positive manifold pressure.

Removing the hose (and plugging the hose so you don't have a vacuum leak) doesn't do anything other than remove fuel cut and pegging the oem boost gauge to atmospheric.

Removing/Disabling the sensor puts you into limp mode because the ECU detects an open/short in the PIM circuit.

[MR2SW22]

Originally Posted by Sang

As it should. The ecu still needs the map sensor for a reading. It just doesn't matter whether that reading is atmospheric pressure/vacuum/or positive manifold pressure.

Removing the hose (and plugging the hose so you don't have a vacuum leak) doesn't do anything other than remove fuel cut and pegging the oem boost gauge to atmospheric.

Removing/Disabling the sensor puts you into limp mode because the ECU detects an open/short in the PIM circuit.

it was mr2speedarizona, we had a nice chat before we all left, cool guy NICE ass mr2, would leave me eatting dust if we dragged. anyways, he told me that he did what i did and just blocked off both ends and his car ran like crap, now if it didn't plug the hose and he had a vac leak i dunno but my car isn't runnin like crap with it plugged.

I've been told it's worth it to get the HKS FCD i use to have on my first 91T, i can set the RPM limit, and it disables the stock boost cut. if this is true please let me know sang, and if you have a nice alternative im all ears.

do you think the JDM ecu will have a higher boost cut? cause im running the stock waste gate no BC, on the jdm ecu.

[MR2SW22]

Originally Posted by Sang

Don't bother installing it. Instead of splicing it in, into your harness, just pull the boost reference line off the MAP.

All the Greddy FCD does is eliminate fuel cut, not adjust it. By installing it, all that happens is you got rid of FC entirely, which is exactly what pulling the vacuum line does.

what do you mean pull the reference line off the map, is that the Vac line we are talking about? or is it an electrical line?

[Sang]

Originally Posted by MR2SW22

I've been told it's worth it to get the HKS FCD i use to have on my first 91T, i can set the RPM limit, and it disables the stock boost cut. if this is true please let me know sang, and if you have a nice alternative im all ears.

The HKS FCD only works on one setting for the mr2. You either, eliminate it completely, or set it at #9 and it sets FC at 17.8 psi (or whatever the max the MAP sensor will allow).

The ONLY FCD worth getting for the gen2, IMHO, is $60 cheaper than the HKS and has infinite adjust ability within the range of the stock MAP sensor. So anywhere between 12.1psi to 17.8psi.

In face, i'll be ordering a Twos R Us FCD in the next couple of weeks.

do you think the JDM ecu will have a higher boost cut?

No, infact a jdm ecu should also have speed cut as well.

Originally Posted by MR2SW22

what do you mean pull the reference line off the map, is that the Vac line we are talking about? or is it an electrical line?

Pulling the vacuum line, plugging it. Then leaving the MAP sensor end open, lets the ECU read atmospheric pressure, 100% of the time.

Pulling the electrical connector, disables the MAP sensor and causes the ECU to enter limp mode.

If you're friend removed the vacuum line, and his car ran like crap, his issues lie elsewhere. A gen2 should not "run like crap" with the vacuum line pulled.

I, as well as countless others, have ran this way for years.

[pothiawala786]

I went to Radioshack today to pick up some diodes for something else, and it just happened to be right next to the PC boards, etc. I remember reading about making your own FCD online and wanted to try it, but couldn't really remember exactly what I needed.

It is similar to the TwosRus FCD, which sells for $37. Heres the link if you plan on trying it. Only thing I dont like about the DIY method is the "setup" on the bottom. I have a pressure gauge, but I'm not sure how I'd apply 14-17 psi accurately to setup/calibrate the FCD. I wonder if I'd just to be able to use the values for resistance posted on the site and use that instead, making it alot easier since you're only using an ohm meter.

DIY FCD

If you're on a budget, or just dont want to spend that much money on a FCD, I would just buy a potentiometer for a few bucks at radioshack, and wire it in right near the ECU. That way, you wont have to worry about the project board and all the soldering on the board. Just wire it up near the ECU where its weather safe and out of harms way. Its not like you'll need to mess with it often.

Total cost will probably be around $4-5, since all you'll need is a pot and some wire, and BGB to know the ECU pinouts.

[jdm ding-dong]

i have the 2s r us, mint little device!

[MR2SW22]

Originally Posted by Sang

The HKS FCD only works on one setting for the mr2. You either, eliminate it completely, or set it at #9 and it sets FC at 17.8 psi (or whatever the max the MAP sensor will allow).

The ONLY FCD worth getting for the gen2, IMHO, is $60 cheaper than the HKS and has infinite adjust ability within the range of the stock MAP sensor. So anywhere between 12.1psi to 17.8psi.

In face, i'll be ordering a Twos R Us FCD in the next couple of weeks.



No, infact a jdm ecu should also have speed cut as well.



Pulling the vacuum line, plugging it. Then leaving the MAP sensor end open, lets the ECU read atmospheric pressure, 100% of the time.

Pulling the electrical connector, disables the MAP sensor and causes the ECU to enter limp mode.

If you're friend removed the vacuum line, and his car ran like crap, his issues lie elsewhere. A gen2 should not "run like crap" with the vacuum line pulled.

I, as well as countless others, have ran this way for years.

Apparently the place that did my rebuild didn't screw on the crank case pressure sensor on the driver side of the motor and oil and vac has been leaking out now and then, they found the leak in 5 minutes (with me standing over them poking around with them) and tighten it, and cleaned off the motor and trans to make it shiney again, that is why my idle was off.

BUT, i figured out why my brand new timing belt is shreading itself to death, i think they left off the Timing belt guide so the belt is walking off the cam gears and rubbing on the timing belt cover, bad stuff. needless to say im pissed, i growned the 2 until i get an new belt and this stupid shop gets my car into there to fix what they ****ed up! and he thinks it's ok to charge me 3 hours labor! if they pull everything off and there is no guide on there, im gonna have a fit like a 3 year old in a candy store

i hate shops that think they know how to work on "anycar" im at my wits end with this shop, i just want my mr2 running normally and not falling appart every month like it has been. Stupid asses couldn't even put a spark plug without braking it.

[RickyB]

Originally Posted by MR2SW22

BUT, i figured out why my brand new timing belt is shreading itself to death, i think they left off the Timing belt guide so the belt is walking off the cam gears and rubbing on the timing belt cover, bad stuff. needless to say im pissed, i growned the 2 until i get an new belt and this stupid shop gets my car into there to fix what they ****ed up! and he thinks it's ok to charge me 3 hours labor! if they pull everything off and there is no guide on there, im gonna have a fit like a 3 year old in a candy store

The guide that holds the belt on is machined into the water pump pulley so there is no way you can leave it off. There is a washer that goes on the crankshaft before you put the timing belt cover, but that doesn't keep the belt on. I've let 3S motors run for hours while checking for oil leaks and coolant leaks with the timing covers off, the crank washer off and nothing to hold the belt in place except the water pump pulley and never seen a belt go anywhere except right where it was supposed to be. I'm not saying that the shop isn't responsible for the timing belt problem. I just don't like to see anyone smeared with misinformation.

[Pop the hood?]

I simply unplugged the vacuum line going to the map sensor and plugged the line. It runs no different at all, besides the fact I can boost 17psi now with out fuel cut

[MR2SW22]

Originally Posted by RickyB

The guide that holds the belt on is machined into the water pump pulley so there is no way you can leave it off. There is a washer that goes on the crankshaft before you put the timing belt cover, but that doesn't keep the belt on. I've let 3S motors run for hours while checking for oil leaks and coolant leaks with the timing covers off, the crank washer off and nothing to hold the belt in place except the water pump pulley and never seen a belt go anywhere except right where it was supposed to be. I'm not saying that the shop isn't responsible for the timing belt problem. I just don't like to see anyone smeared with misinformation.

according to the BGB that washer you speak of is refered to as a "timing belt guide", and i was shown a good pic of a side view of a 3s (thanks mopwer)and i see that "guide" on the water pump your talking about also, that's why im at a lost of words as to what could be the problem. i told the mechs here at my work about what's happening and they told me if that washer/timing guide piece is left off the belt can move. 3 toyota trained techs told me that, so naturally i take their opinon into consideration because they have WAY more experience than me .

im willing to bet that the mech that did my work did screw something up, based on the shoty job he did as a whole. he didn't screw in a senor on the side of the head and it leaked oil for 2 months, i took it back and a new tech that "finished" my rebuild found the leak in minutes, fixed it then he told me that the guy that use to work there that started my rebuild wasn't a good mechanic, i was like . they also over torqued 3 of 4 of my spark plugs, and 1 of the plugs was broke in half when i pulled it out, they were brand new NGK iruidium plugs and because it was broke, it was arching at high RPMS . i don't trust 2 of the guys that work there, but the one that is working on the car now seems to have a brain in his head, and he's helpful and honest. i told him i wanted him to work on my car this time for that reason.

[mr2speedarizona]

Hey all yah it was me it made all the difference having a FCD.

[RickyB]

Originally Posted by MR2SW22

according to the BGB that washer you speak of is refered to as a "timing belt guide", and i was shown a good pic of a side view of a 3s (thanks mopwer)and i see that "guide" on the water pump your talking about also, that's why im at a lost of words as to what could be the problem. i told the mechs here at my work about what's happening and they told me if that washer/timing guide piece is left off the belt can move. 3 toyota trained techs told me that, so naturally i take their opinon into consideration because they have WAY more experience than me .

im willing to bet that the mech that did my work did screw something up, based on the shoty job he did as a whole. he didn't screw in a senor on the side of the head and it leaked oil for 2 months, i took it back and a new tech that "finished" my rebuild found the leak in minutes, fixed it then he told me that the guy that use to work there that started my rebuild wasn't a good mechanic, i was like . they also over torqued 3 of 4 of my spark plugs, and 1 of the plugs was broke in half when i pulled it out, they were brand new NGK iruidium plugs and because it was broke, it was arching at high RPMS . i don't trust 2 of the guys that work there, but the one that is working on the car now seems to have a brain in his head, and he's helpful and honest. i told him i wanted him to work on my car this time for that reason.

That washer/guide should be installed to keep the timing belt from picking up dirt from outside the timing belt cover and it does generally keep the belt from walking off if the lower idler pulley is slightly worn, but it by itself should not cause the problem you describe. I fully understand your concerns about the folks who work on your car. That same concern is the reason I do all of the maintenance on my MR2 myself.

[MR2SW22]

Originally Posted by mr2speedarizona

Hey all yah it was me it made all the difference having a FCD.

lol, there you are arizona. been waiting to see you chime in, hay you coming to the tilted kilt soon? i'd love to rid in your mr2 to see if mine can get close to your hp range.

Originally Posted by RickyB

That washer/guide should be installed to keep the timing belt from picking up dirt from outside the timing belt cover and it does generally keep the belt from walking off if the lower idler pulley is slightly worn, but it by itself should not cause the problem you describe. I fully understand your concerns about the folks who work on your car. That same concern is the reason I do all of the maintenance on my MR2 myself.

yea, im stuck in arizona with no lift, and all my tools minus hand tools back in cali in my parents garage, i can't even do an oil change at my appartment... i should get the car finished on monday, and i will take pics and let you guys know what happends.

[MR2SW22]

Originally Posted by RickyB

That washer/guide should be installed to keep the timing belt from picking up dirt from outside the timing belt cover and it does generally keep the belt from walking off if the lower idler pulley is slightly worn, but it by itself should not cause the problem you describe. I fully understand your concerns about the folks who work on your car. That same concern is the reason I do all of the maintenance on my MR2 myself.

your gonna laugh , i was like ready to do this to the mech>. he put the Timing belt guide/spacer on backwards, and it has a shape like this
__
/ \

according to the guy. so when put on backwards instead of guiding the belt, it rubs the belt...

check it out, half the orignial size of the belt...

[canadam]

Originally Posted by Sang

No, infact a jdm ecu should also have speed cut as well.

Pulling the vacuum line, plugging it. Then leaving the MAP sensor end open, lets the ECU read atmospheric pressure, 100% of the time.

I, as well as countless others, have ran this way for years.

Will fooling the MAP also get around the speed control? I have a Greddy Speed Cut Eliminator, I'm just not sure if it's worth installing.