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-   -   Need Fuel Controller and AFR gauge advice (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/need-fuel-controller-afr-gauge-advice-738668/)

ATRON3000 03-14-08 11:21 AM

Need Fuel Controller and AFR gauge advice
 
Ok guys, I'm new to these boards, so please be patient and talk low and slow with the terminology.

Just bought this 88 rx-7 with a somewhat freshly rebuilt 89 motor in it. Deleted smog pump, A/C & P/S... has headers, no cat and a duel straight thru exhaust(rediculously loud... but i love it)... seems like its street ported.. but I cant tell if the injectors are stock(maybe someone can help me id them) but this thing is running SUPER DUPER RICH... I want to get a fuel contoller and a AFR gauge to help me tune this thing leaner... any suggestions?

I have seen the AEM AFR guage with the digital readout...
http://www.aempower.com/ViewCategory.aspx?CategoryID=67
I like that because it is accurate to 0.1... but the only fuel controller i have come across is the apexi.... what other options do I have.... and is there a fuel controller that has a built in ARF(digital numbers not the silly lines) and come with a wide band 02 sensor?

I have been impressed with the level of knowledge on these boards so I would most def appreciated any advice you guys could hit me off with

iox106 03-14-08 11:57 AM

what do you mean super duper rich? Rx7 run rich from the factory. If its really bad it could be a leaky injector.

LogicFoxX 03-14-08 03:20 PM

Never preferred AEM, paying too much for the name. I do suggest getting a wideband first though and fixing your rich problem before investing in a safc. As running rich could be anything from electircal components to mechanical components, to damaged vac line from fpr , or poor compression, etc.

classicauto 03-14-08 04:15 PM


Originally Posted by LogicFoxX (Post 7978460)
Never preferred AEM, paying too much for the name. I do suggest getting a wideband first though and fixing your rich problem before investing in a safc. As running rich could be anything from electircal components to mechanical components, to damaged vac line from fpr , or poor compression, etc.

Actually, the AEM UEGO wideband is about the cheapest wideband on the market. Note "about".

Theres many options in around the price range such as innovate LM1 and PLX Devices. I'd recommend something with an NTK sensor, but really they all work.

As far as the OP's richness goes, these cars run rich from the factory, and even a tuned turbo car will be "rich" compared to a piston engine of the same power level. Just a function of the engine design and how it runs. They need a little more fuel. THat being said, the factory ECU runs on the fat side of a safe tune, so some fuel can be taken out even if everything is operating perfectly (good fuel pressure, good injectors etc)

An S-AFC is an "acceptable" tpye of tuning tool, but its obviously limited. Should suit your needs just fine however.

LogicFoxX 03-15-08 12:44 PM

Perhaps I haven't seen enough of the market, though my lc1 setup was about 260 from local dealer and my laptop works fine for airflow tuning. And I have to say haven't seen a lot cheaper than that.
Anyways good luck either way.

ATRON3000 03-17-08 02:57 PM


Originally Posted by classicauto (Post 7978652)
Actually, the AEM UEGO wideband is about the cheapest wideband on the market. Note "about".

Theres many options in around the price range such as innovate LM1 and PLX Devices. I'd recommend something with an NTK sensor, but really they all work.

Why is the NTK better than the Bosch? What type does the LM1 come with?


Originally Posted by classicauto (Post 7978652)
As far as the OP's richness goes, these cars run rich from the factory, and even a tuned turbo car will be "rich" compared to a piston engine of the same power level. Just a function of the engine design and how it runs. They need a little more fuel. THat being said, the factory ECU runs on the fat side of a safe tune, so some fuel can be taken out even if everything is operating perfectly (good fuel pressure, good injectors etc)

An S-AFC is an "acceptable" tpye of tuning tool, but its obviously limited. Should suit your needs just fine however.

I fully understand that running rich is the norm with these cars but I believe mine is running excessively rich... It almost smells like a gas leak at idle... and I have checked for leaks.

The injectors might be a problem that I am currently looking into, I dont know if they are stock, and also plan to have them cleaned. Would Low fuel pressure cause me to run rich?

arghx 03-17-08 03:01 PM

it never hurts to check your TPS.

classicauto 03-17-08 03:11 PM


Originally Posted by ATRON3000 (Post 7987835)
Why is the NTK better than the Bosch? What type does the LM1 come with?

I'm not sure exactly what manufacturing or composition differences between the two make the NTK better, but side by side comparison shows the Bosch sensor to react slower, fall out of calibration easier (but Innovate should have free air calibration....)and have a slightly shorter lifespan. The Bosch sensor "works" fine, but from an ultimate acuracy standpoint, NTK is superior. The LC1 will come with a bosch sensor as does AEM.


Originally Posted by ATRON3000 (Post 7987835)
I fully understand that running rich is the norm with these cars but I believe mine is running excessively rich... It almost smells like a gas leak at idle... and I have checked for leaks.

What exhaust is on the car? Is the charcoal canister and ventilation system working properly?


Originally Posted by ATRON3000 (Post 7987835)
The injectors might be a problem that I am currently looking into, I dont know if they are stock, and also plan to have them cleaned. Would Low fuel pressure cause me to run rich?

Low fuel pressure shouldn't cause a rich condition per say.........but it may cause even fuel delivery if its excessively low, which could lead to unburnt fuel coming out of the engine, which could lead to fuel smelling exhaust. But it'd have to be extremely low to really cause that type of problem.

well uhhh 03-17-08 04:16 PM


Originally Posted by ATRON3000 (Post 7987835)
It almost smells like a gas leak at idle... and I have checked for leaks.

The injectors might be a problem that I am currently looking into, I dont know if they are stock, and also plan to have them cleaned. Would Low fuel pressure cause me to run rich?

That gas smell could actually be gas, check your pulsation dampner, nobody likes engine fires. (i know you checked for leaks, but being new, i didn't know if you knew about it)

i don't believe low pressure would have anything to do with running rich. Injector cleaning is a wonderful idea and for the price, ~100 bucks, you cant really go wrong.

LogicFoxX 03-17-08 08:11 PM

check to see if the fuel tank vent hose is just sitting there in the engine unhooked too, mine was like that and smelled very strongly of fuel during run times.


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