wdwflash

I've got a '87 Turbo with stock 550 injectors(new) in a car thats not an RX7. Its run by a Haltech E6K and is running "Hitman" maps. I'm running a very large M/Benz german fuel pump. Its got a very free flowing exhaust with no cats, etc. I believe its running way to rich as it fouls plugs in 40 miles of being cleaned. On inspection, the plugs are black and have carbon on them. The exhaust is also black at the tip. Would running a very large M/Benz fuel pump add to the volume of fuel injected? How far back should I cut the fuel maps? What decrease in fuel maps is safe.

Wankel7

Uh.....you have done all this work to your car and you have not installed a wideband? I think you forgot something

We can't sniff your exhaust from here and tell you your AFR. Either lean it until it starts hessitating and then blows up. Or, buy a wideband and stop guessing.

A standalone isn't something you can install, dig up a base map, and go have fun.

James

wdwflash

I'm new to computer cars, so a wideband what? It was my understanding when I researched the haltech that it was a very tuneable stand alone computer. I need some constructive advise, not something sending me to the store to buy more equipment. Do you have experience with a Haltech E6k and the turboII or not? The plugs are black and the exhaust is black, which leads me to believe I'm running rich. As I asked before, could a higher volume bigger fuel pump cause this? Has anyone else had this problem? BTW, I work on marine diesels to 5000hp and marine steam plants to 35,000hp so I understand a little about the mechanical way things work, I'm just new to the Haltech and am looking for some constructive guidance. I'm trying to keep from leaning it out enough to cause damage. As I stanted before I'm running "Hitman" maps for the '87 turboII with stock 550cc injectors, so from what I've been told in the past, his maps are very well thought out, but I've thrown in a different fuelpump in the mix and want to know if anyone has had this problem before. (The maps I got with the haltech from Rotary performance would not run the car and a web site member "Arturo", was kind enough to provide me with the Hitman maps.)

eViLRotor

iTrader: (2)

Yes, the Hitman maps are very well thought out.

But, ANY deviation from his base setup will require a tweaking of the maps, and that includes a fuel pump that flows more, or a different fuel pressure from what the basemap was made with.

Certainly, you can tune your idle and lean out the vacuum maps by feel or sound. The car will let you know when you are getting too lean on the highway.

But there is no way that you can tune the boost portion of the map without the correct tools. The minimum requirement for this is an EGT gauge and a lot of experience(ala RETed). But, you would be better served with your own wideband oxygen sensor, or a professional tuner and a dyno.

Claudio RX-7

iTrader: (1)

It should be pointed out that ALL ENGINES, and i mean ALL ENGINES, are different, even engines with exactly the same mods and parts will probably require slightly different or sometimes very different map tuning.

And as evilRotor indicates the hitman's maps will be very very good for the exact car he did, no 2 cars are the same. You also dont know what exact fuel pressure he had on his, and the exact extent of the porting job that engine had, etc., so its not an exact science.

You need a wideband O2 sensor and an EGT gauge to properly dial in your setup.

Wankel7

Yeah, I have a 91 TII and an E6K...abit new to the Haltech world but I am learning...

You asked what a wideband was....

Basicly, most computer controled cars have an oxygen sensor. This oxygen sensor is only accurate at an Air/Fuel ratio of 14.7:1 which is know and stoichmetric. However, when you are tuning a car for full power you cannot run that lean. You need to run richer...say an AFR of 11.0:1.

How do you know if your AFR is 11.0:1 if a regular oxygen sensor is only accurate at 14.7:1? You purchase a wideband oxygen sensor. Now, you need a controller to control and display the readings from the sensor.

With this tool you can dial in your E6K.

I am rather partial to the Techedge equipment....

http://wbo2.com

James

RETed

Why not get a wide-band or EGT gauge (or both!) and go from there?

If you know it's running rich, why not lean it out?

We can't tell you *how much* to knock it down - that's like asking how many fingers you're holding up!

Don't boost the car and start leaning the fuel map down.
If you run it too lean, the engine will just die and not run right.
If you're on the verge of going lean, the engine will "lean surge" on you - rythmic pulsing.
Just jack the fuel just a little bit more to get rid of that, and you're basically at optimum tune.

Please also read the Haltech manual, because there is also a lot of useful information covering basic tuning tips such as this.

Good luck!


-Ted

wdwflash

Thanks all for the good advice. I'm very familiar with air/fuel ratios from working with diesel engines and marine stream plants.(the turbos I work on are about the size/weight of an RX7) Can I piggyback an EGT gauge off of the 4-wire O2 sensor I'm using with the Haltech or do I have to drill a new O2 bung (It would be a real pain to get at in my custom installation.) I see Haltech has a device called a "haltuner" that seems to be exhaust gas-air/fuel ratio gauge. Anyone had experience with this device? I kind of suspected that the larger feedpump I installed (M/Benz) would affect the volume of the fuel and its spray pattern.

wdwflash

Just did a little research. So an EGT measures the temp of the exhaust or as used on marine diesel engines, a "pyrometer." If so, this seems like a very simple device to to hook up as its only doing one function and if you know the temp your combustion exhaust should be, this would tell me if I'm rich or lean. The only problem I can see is that unlike most large marine diesel engines which run at one rpm (like 900 or 64rpm,etc), the rotary runs at many rpms, thus the computerized gauge that Wankel7 recommends.

RETed

Okay, you seem to be a bit confused here, but I think you figured it out.
Yes, it's also known as a pyrometer.
It measures the temperature of the exhaust gases exiting the engine.
This will, at the very least, tell you if you're okay or IN TROUBLE(!!!).
The EGT gauge typically consists of the gauge, an EGT probe / sender, and a connecting harness.
The EGT probe needs to be "installed" in the exhaust system, preferrably closest to the engine (exhaust ports).


That devices uses a normal, narrow-band O2 sensor.
The set-up is basically only to tell you if you're extremely rich, extremely lean, or at dead stoic.
You really should not be "fine tuning" with such a device.


Do you happen to know the flow rate of the fuel pump?
The stock Turbo II fuel pump flows about 180 liters / hour.
Not many stock fuel pumps will run around that range or higher.
I don't know of that many MB stock OEM fuel pumps that can?


-Ted

Claudio RX-7

iTrader: (1)

To add to RETed's comments and to answer his fuel pump question, the factory fuel pump on an RX-7 is great for stock performance, but not much more. The Walbro fuel pumps have proved to be great performers and are very cheap, as far as stock fuel pumps that flow better than the TII pump are the 3rd gen RX-7 pump, the Toyota Supra MK4 pump, the Nissan Skyline pump, the 3000GT twin turbo pump, and more over the Mazda Eunos Cosmo 3 rotor pump.

As far as getting your engine tuned right, the Narrow band O2 sensor only provides a ver rough reference curve of 0-1v with limited effectiveness. The Wideband O2 sensors have a 0-5v range and are very effective in reading proper O2 ratios, the EGT pyrometers (exhaust gas temp) gauges will tell you if the exhaust is getting too hot and too hot means detonation with is the BIG NO NO for a rotary.

Innovative Motorsports, TechEdge, FJO, PXL, AEM, etc., are making really affordable wideband controllers that have outputs/provisions for your ECU to read and datalogg.

You should also know that the 550cc injectors wont allow for that much horsepower, less than 280 tops, so putting in bigger secondaries will be a benefit.

wdwflash

Would you recommend 770cc injectors all around for good street driving (I have the hitman maps for those) or 550 primary and larger(?) for secondary. Once again, thanks all for the great advice and knowledge. I really don't know the output of the M/Benz fuel pump as I bought it on ebay, but when I tested it against a stock second gen RX7 fuel pump it seemed to fill a bucket with liquid about twice as fast. The inlet and outlet sides of the pump are also much larger than an rx7s. Also size wise, its twice as large as an rx7 pump.

Claudio RX-7

iTrader: (1)

Yes those pumps will pour more volume, but not necesarily at the addecuate pressure, specially if you have a rising rate regulator. The best combination for street use, if you dont want to go beyond 300hp is around 550/850 injectors. Or if you want to have enough gas always use 550/1600. If you are unsure of the pump just get a pressure gauge, hook it up to the fuel line and monitor your fuel pressure and find out how its behaving.