Extreme Frustration [aka owning a 7M]

[Furyian]

Sweaty, defeated, hungry, and tired ... but out of all of them very VERY defeated ...

I have a 89 7MGTE in an 86.5 Supra. As it stands, I can get the car to crank no problem. It does idle pretty high [1500-2000], but cranks no problem. When you rev it, it studders big time doesn't want to go past 3000. I connected the HKS FCON that came with the car [yes I know FCON is not the greatest and trust me if I had the money I would rather a WB 02 sensor and an SAFC at the least]. After hooking it up, it will roll over but won't start and it smells like its dumping too much fuel into the engine. I do have a GCC and its hooked up too.

The reason I hooked up the FCON with it running like that is because without it hooked up, there was no sensor to read boost. With the unit hooked up, I am able to use the sensor that came with the kit.

As far as the idle, I contacted previous owner and he noted to me that he might have forgotten the seal washer when he put the ISC back on [waiting for one to come in from the dealership]. And he also had removed the 3000 pipe. The vacuum hose coming off of the IAC is hooked to the intercooler piping. Isn't that wrong? Shouldn't it be hooked in by the AFM before the turbo? Without the FCON hooked up [it can't read turbo pressure] and it throwing extra air through the IAC wouldn't that cause it to not want to rev?

Also, without the FCON hooked up it cranks up fine yet with it hooked up it doesn't start ... any ideas?

Thank you guys forehand for your dedication to helping people and to the people that want to flame me sorry for my lack of knowledge I'm trying to learn.

 

[gaboonviper85]

Remove fcon and fix issues....check codes!!!!....also I have the stock boost sensor if you're interested. $20+shipping

 

[Furyian]

The codes are clear. I have no check engine lights. Personally I would love to ditch the FCON. I might look into getting that stock boost sensor. I also failed to mention that he hooked up an OBX FMU. Would this cause me to run rich as well?

Where would the boost sensor mount? On the driver side? The originally came with the 7MGE engine.

 

[dumbo]

It mounts on the left by the injector resistor block. You know you don't need to see your boost right? That sensor is only for the gauge.

Also you can have codes without a CEL. And your right the ISC should be hooked pre turbo.

 

[Furyian]

well that would certainly solve my idle issue ... Since there is no more black hose with the AFM how would I connect a hose to the ISC? Am I going to have to make a place myself?

 

[dumbo]

well that would certainly solve my idle issue ... Since there is no more black hose with the AFM how would I connect a hose to the ISC? Am I going to have to make a place myself?

Yah have to go custom if you don't have stock "accordian". I'm not saying that will fix your idle problem though.

I'm on my computer now not my iPhone, check your codes.
http://cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=23

 

[supradjza80]

New accordion pipe is only 50$ shipped through elmhurst toyota...

 

[Furyian]

I see 3 vacuum ports coming off of the acordian hose in pictures. I know one of them goes to the ISC. What about the other 2?

 

[dumbo]

I see 3 vacuum ports coming off of the acordian hose in pictures. I know one of them goes to the ISC. What about the other 2?

One is the BPV, and one is the power steering up?

 

[adampecush]

no, the other is positive crankcase ventilation. (idle up is on the bottom of the accordian tube)

 

[Furyian]

Okay next question ...

I have removed the FCON [the trash can may be the next install for that]. The stock accordion hose won't work because the turbo is bigger then stock. As it stands, there is virtually no room with the AFM and air filter the way the previous owner had hooked it up. I got my hands on a MAFT. I have the box with the 3" GM sensor [I don't have the digital box]. Should I go through the problem of installing the MAFT and say the hell with the AFM all together. If I do hook up the MAFT should I just cap the ISC? Or do I just worry about the MAFT later and try to custom fit a nipple by the air filter so I can pull a vacuum for the ISC?

Also with hooking up the MAFT wouldn't I need a WB 02 sensor?

 

[tlo86]

dont people usually just throw a filter on the ISC?..

 

[dumbo]

no, the other is positive crankcase ventilation. (idle up is on the bottom of the accordian tube)

Doh! I knew that haha.

dont people usually just throw a filter on the ISC?..

Only if your ECU is MAP based.

 

[tlo86]

Only if your ECU is MAP based.

so with a maft you still connect the isc behind the filter?

 

[dumbo]

so with a maft you still connect the isc behind the filter?

Maft I belive so.
Maft Pro, runnning speed density(MAP Based) you just run a filter on your turbo/isc if you choose.

 

[tlo86]

so is he using a maft pro or what?

either way capping it off is not going to work for anything strike that off

 

[WhtMa71]

The codes are clear. I have no check engine lights. Personally I would love to ditch the FCON. I might look into getting that stock boost sensor. I also failed to mention that he hooked up an OBX FMU. Would this cause me to run rich as well?

Where would the boost sensor mount? On the driver side? The originally came with the 7MGE engine.

YES! Assuming it's hooked up right...Get rid of it, reconnect all stock fuel. Do you have an upgraded fuel pump? Way to measure fuel pressure?

 

[Furyian]

From what I'm seeing, the FMU is hooked up right.

Update: We ended up plugging off the ISC and it idled smoothly at 1k. But taking it down the road and trying to make boost, it pulls pretty good and when it starts making boost it cuts the engine off. I was thinking boost leak but rechecked everything and no boost leaks. The only other thing I can see if the FMU is causing it to drop like that. Can some explain why the FMU would case me to run too rich? From the looks of things, the FMU only ups the fuel when boost is made which is why there is a vacuum fitting on top that ties into the boost pressure sensor. I should be able to just by a boost pressure sensor and it function correctly?


There is an upgraded fuel pump on there too

 

[WhtMa71]

The FMU is a very crude fuel management system. It's a rising rate fuel pressure regulator so depending on the model, for every pound of boost it sees it rasies fuel pressure by X amount. Most of them are 12:1 so it raises fuel pressure 12psi for every psi of boost.

GET RID OF IT. You don't need it. Yes that is why your car is running rich. Probably extremely rich since you also have an upgraded fuel pump.

Ditch the FMU and run the stock fuel pressure regulator. If you have an upgraded pump you will probably also still run rich unless you drill out the J tube on the side of the block. It would also be a good idea to go ahead and upgrade to an adjustable fuel pressure regulator such as the aeromotive unit.

 

[dumbo]

From what I'm seeing, the FMU is hooked up right.

Update: We ended up plugging off the ISC and it idled smoothly at 1k. But taking it down the road and trying to make boost, it pulls pretty good and when it starts making boost it cuts the engine off. I was thinking boost leak but rechecked everything and no boost leaks. The only other thing I can see if the FMU is causing it to drop like that. Can some explain why the FMU would case me to run too rich? From the looks of things, the FMU only ups the fuel when boost is made which is why there is a vacuum fitting on top that ties into the boost pressure sensor. I should be able to just by a boost pressure sensor and it function correctly?


There is an upgraded fuel pump on there too

Vacum leak.