Fuel 19lbs EV6 fuel injectors, what fuel pressure???

[90sickfox]

The computer looks at the engine temperature and adjusts fuel depending on the warm up cycle. It could be the wires for the ECT sensor are grounded or disconnected. It should be in the pipe that runs to the heater hose from the front right corner of the intake ( passenger side ). It can cause a car to run rich and won't throw a code. There is an ohms test for that sensor somewhere on the interwebs. Not saying this is your issue but is worth a check. I get better than 9mpg with my twisted wedge headed 331with a turbo, 42lb injectors, 3.55 gears, and tko600.

 

[PonyGTrider]

The bigger alternators will typically charge at 14.3-14.4 volts just like the stock unit. The higher amperage helps with loads added to the electrical system like stereo amplifiers, electric fans, aftermarket ignitions, etc. This will keep the voltage from dipping which keeps the fuel pump delivering at a more steady volume so they actually help with fuel delivery.

Also, you should be removing the vacuum line and plugging it when setting the fuel pressure at idle.

That’s what I thought about the charging system vs fuel delivery system.

Yes I know, I unplug the vacuum line/block it/adjust the pressure/reconnect the vacuum line

The computer looks at the engine temperature and adjusts fuel depending on the warm up cycle. It could be the wires for the ECT sensor are grounded or disconnected. It should be in the pipe that runs to the heater hose from the front right corner of the intake ( passenger side ). It can cause a car to run rich and won't throw a code. There is an ohms test for that sensor somewhere on the interwebs. Not saying this is your issue but is worth a check. I get better than 9mpg with my twisted wedge headed 331with a turbo, 42lb injectors, 3.55 gears, and tkoulua

I tested the ECT unpluged and it switches the resistance fine, it goes down to ~ 2.5 K Ohms @ normal operating temperature. I haven't checked the voltage with the sensor pluged, I will do that today. It supossed to go down to about 0.5 to 0.6 Volts @ normal operating temperature. Thanks

 

[rednotch]

Thanks for sharing your extended and interesting comment and you’re right the whole facts about my combo don’t add up. It is like joking or lying about the it, is like by mistake I was running 30 lbs injectors with a stock MAF. But all what I disclosed on my setup are real facts, that’s why I’m searching for some answers.

Right now I’m returning from a test drive after I adjusted the fuel pressure with my Kirban fuel pressure regulator to 30 psi with the vacuum ON, drove it hard not redlining it but hard and it ran really good with no pinging. There was no check engine for possible lean condition.
At the bottom is the FUEL PRESSURE GAUGE I’m using which correlates with my fuel pressure gauge tool. The reading on the gauge is not the actual pressure, it is just residual pressure after shutoff .
Any ideas or comments?

I'm just using that car as an example of one that would benefit greatly from a tune for drive ability and mileage perspective. There's only so much the stock ecu can compensate for, yet I drive it almost daily and never see the cel light and don't go threw gas anywhere near the rate you do. I all ways have stored codes for emissions, yours isn't even tripping one. Rail pressure has nothing to do with tank pressure, A vented tank will evaporate fuel, whole point of the evap system. Most mustangs no longer have them to keep pressure in the tank. if its extremely hot often where you are you might be seeing more evaporation then others.

I'm sure your sick of answering questions but how often between fill ups do you go? The fuel pressure isn't going to change the flow rate enough to really do anything for mileage if those are legit ford injectors and not China knock offs. That's duty cycle, and fuel command more then anything, the flow rate won't change enough from pressure alone. The adjustable regulators where old school tricks to work at the track because the computer will adapt around it eventually if its in the limits of its program. If its really an engine tune issue at this point, it might be time to look into tuning aids like a used quarter horse, or a newer system like term x or pimpx and throwing a wide band on and playing with the fuel tables. Trying to do a mail order tune on a old eec IV for drive ability issues is not something that would be easy. Chips need to be burned each time. Its not like new stuff where changes are easily done with out something like a quarter horse. One thing I would also check is the bap sensor on the firewall make sure no one added vaccum to it.

 

[PonyGTrider]

I'm just using that car as an example of one that would benefit greatly from a tune for drive ability and mileage perspective. There's only so much the stock ecu can compensate for, yet I drive it almost daily and never see the cel light and don't go threw gas anywhere near the rate you do. I all ways have stored codes for emissions, yours isn't even tripping one. Rail pressure has nothing to do with tank pressure, A vented tank will evaporate fuel, whole point of the evap system. Most mustangs no longer have them to keep pressure in the tank. if its extremely hot often where you are you might be seeing more evaporation then others.

I'm sure your sick of answering questions but how often between fill ups do you go? The fuel pressure isn't going to change the flow rate enough to really do anything for mileage if those are legit ford injectors and not China knock offs. That's duty cycle, and fuel command more then anything, the flow rate won't change enough from pressure alone. The adjustable regulators where old school tricks to work at the track because the computer will adapt around it eventually if its in the limits of its program. If its really an engine tune issue at this point, it might be time to look into tuning aids like a used quarter horse, or a newer system like term x or pimpx and throwing a wide band on and playing with the fuel tables. Trying to do a mail order tune on a old eec IV for drive ability issues is not something that would be easy. Chips need to be burned each time. Its not like new stuff where changes are easily done with out something like a quarter horse. One thing I would also check is the bap sensor on the firewall make sure no one added vaccum to it.

it makes a lot of sense what you're saying, ultimately I will have to bite the bullet and search for at least a used binary quarterhorse. The BAP sensor does not have a vacuum hose that's for sure.

The previuous comment talks about testing the ECT sensor, well the sensor is fine and I started checking the wires in its plug. Upon disconnectin the sensor I opened the switch and checked the voltage in the plug. As far as I know one wire should read a 5 volts signal (pin # 7 at the ECU) which it reads correctly. the other wire as far as I know is ground (pin # 46 at the ECU), well just for the sake of it I measured voltage and it gave me 0.45 Volts. And then I measured voltage in between both wires placing the positive lead to the 5 Volts signal wire (7) and the negative on the supossed ground (46) and had a reading of 4.54 Volts. After this I connected pushed the connector onto the sensor and took a reading, it gave me 2.93 Volts on a stone cold engine @ ~ 74.5 degrees F ambient temperature which more or less correlates with the ECT Temp/Volts chart.
Is this correct? My biggest question is why do I have voltage on the wire that supossed to be ground? should I be worried about this specific reading, or should I just disregar it???

 

[rednotch]

46 is Sig return, ties into all the sensors, usually burns the trace if it sees over 5 volts. What your seeing is pretty normal for a 5 volt sensor, I don't know if the temp - readings are correct off hand though but looks normal.

 

[PonyGTrider]

46 is Sig return, ties into all the sensors, usually burns the trace if it sees over 5 volts. What your seeing is pretty normal for a 5 volt sensor, I don't know if the temp - readings are correct off hand though but looks normal.

I just monitored the voltage at the ECT sensor during a warmup cycle and the readings are very close to the reference chart to within 0.05 volts. So I don’t think my temperature sensor or wiring is at fault as to induce that terribly low MPG. So now to another possibility and really not too many left

 

[PonyGTrider]

The computer looks at the engine temperature and adjusts fuel depending on the warm up cycle. It could be the wires for the ECT sensor are grounded or disconnected. It should be in the pipe that runs to the heater hose from the front right corner of the intake ( passenger side ). It can cause a car to run rich and won't throw a code. There is an ohms test for that sensor somewhere on the interwebs. Not saying this is your issue but is worth a check. I get better than 9mpg with my twisted wedge headed 331with a turbo, 42lb injectors, 3.55 gears, and tko600.

I just monitored the voltage at the ECT sensor during a warmup cycle and the readings are very close to the reference chart to within 0.05 volts. So I don’t think my temperature sensor or wiring is at fault as to induce that terribly low MPG. So now to another possibility and really not too many left

 

[Dan02gt]

Do you happen to have access to a stock air box? The 90* bend in aftermarket CAI is known to throw off the MAF sensor’s readings. It would be worth a try to throw the stocker on if you have one.

 

[Noobz347]

Do you happen to have access to a stock air box? The 90* bend in aftermarket CAI is known to throw off the MAF sensor’s readings. It would be worth a try to throw the stocker on if you have one.

This is a great suggestion. You can also try re-clocking the MAF to see if it has an effect.

 

[PonyGTrider]

Do you happen to have access to a stock air box? The 90* bend in aftermarket CAI is known to throw off the MAF sensor’s readings. It would be worth a try to throw the stocker on if you have one.

I still have the stock filter box fitted with a K&N filter and tried it many times … no difference. I’ve tried everything and the mystery persists… Where does my fuel is going!!! ???

 

[PonyGTrider]

This is a great suggestion. You can also try re-clocking the MAF to see if it has an effect.

I’ve tried the stock Box. I have the screen mesh before the MAF tube and that supposed to take care of the turbulence caused by the CAÍ.
I’m to a point that I might sell this engine and build a 408 stroker… At least this is a good excuse to make something else

 

[Bullitt347]

We have pretty much eliminated the car.
The only thing left is the driver, you.
You must have the worst driving habits...Lol.

 

[General karthief]

Something is nagging at me anyway, my junk was getting 11-12 mpg with miss-matched modifications, then a stock block, tubular intake and suckling hot air from the dog house got 13-14 and I have a heavy right foot, I don't run 'in the pack' I GTH away from those spaghetti taco munch'n non-drivers, I'm stumped, I will say the I had a 85 Bronco ll that didn't like Citco gas, I got twice the mpg with any other brand so maybe try a different brand?
I know most fuels are processed basically the same but

 

[limp]

I had a Merkur XR4ti that ended up becoming my beater driver car for about 10 years.... The last year or so, I could not get it to idle correctly. change some parts in it and finally gave up.. After I sold it the new owner called me and told me it was a plugged vacuum line... He was a Merkur guy ( the car has a following I guess) and he knew where to go....
Obviously something isn't quite right you just haven't found it.....

 

[limp]

And old friend of mine is probably the best mechanic I know... I was at his house one day and a Chevy truck was in his shop.. A nice lifted truck with a brand new BBC engine in it... It was well done...
Jeff asked me to listen to the truck after he started it.... He was just getting ready to take the oil pan off and check some bearings... When he started it the engine just shreeeked like a banshee, fingernails on a blackboard sound....
I took one look at it a figured it out.... Popped off the oil filler rubber plug on one valvecover, the other side had a PCV valve in it and the shreek was gone..... In all fairness I had just read an article the day before on how to correctly run a PCV system on a car...... The engine needed a vent on the valve cover that had the rubber plug in it... The Shreek noise was the engine/PCV valve sucking in air through every crack in the engine.....

I want to say again, Jeff is the BEST mechanic I know so to say the least he was pretty upset with himself and double so that a much lesser mechanic ( me) figured it out.......

You need some new eyes on it........

 

[Dan02gt]

I’ve tried the stock Box. I have the screen mesh before the MAF tube and that supposed to take care of the turbulence caused by the CAÍ.
I’m to a point that I might sell this engine and build a 408 stroker… At least this is a good excuse to make something else

Some might not agree, but I feel that you should really have bigger injectors in your car. The '93 Cobras came with 24lbs injectors and your combo should make significantly more power than one of those. It might be worth it to upgrade to a 30lb injector with matching MAF.

One other thing to try it having the car tuned. I had mine tuned by Decipha at efidynotuning.com using a Quarterhorse. We spent a lot of time logging fueling to ensure that A/F was correct and it's been one of the best purchases I have made for my Fox. My combo is very similar to yours and I average 17-18 mpg in mixed driving and even better on the highway. Unfortunately Moates closed up shop but you might still be able to get your hands on one. Heck it's worth it just for the diagnostics ability to see the output of every sensor in real time on your laptop.

 

[PonyGTrider]

We have pretty much eliminated the car.
The only thing left is the driver, you.
You must have the worst driving habits...Lol.

Very much
I wonder if the charcoal canister have anything to do with my issue but then I conclude that I can’t blame that thing for the disappearance of close to half of my fuel….
The damn charcoal canister is completely soaked i

 

[PonyGTrider]

Something is nagging at me anyway, my junk was getting 11-12 mpg with miss-matched modifications, then a stock block, tubular intake and suckling hot air from the dog house got 13-14 and I have a heavy right foot, I don't run 'in the pack' I GTH away from those spaghetti taco munch'n non-drivers, I'm stumped, I will say the I had a 85 Bronco ll that didn't like Citco gas, I got twice the mpg with any other brand so maybe try a different brand?
I know most fuels are processed basically the same but

I will go that route once I replace the EV6 injectors with the ford fat ones same 19lb. I was flushing them and they seem to flow a nicest fine mist compared to the skinny ones I’m running right now. Also I will replace my charcoal canister before that sucker ignaties the whole engine bay… that would be nasty,

 

[PonyGTrider]

I had a Merkur XR4ti that ended up becoming my beater driver car for about 10 years.... The last year or so, I could not get it to idle correctly. change some parts in it and finally gave up.. After I sold it the new owner called me and told me it was a plugged vacuum line... He was a Merkur guy ( the car has a following I guess) and he knew where to go....
Obviously something isn't quite right you just haven't found it.....

You’re right it could be anything, once the frustration frees me up a little I will start from the beginning, from the basics.
Thanks man

 

[Bullitt347]

Very much
I wonder if the charcoal canister have anything to do with my issue but then I conclude that I can’t blame that thing for the disappearance of close to half of my fuel….
The damn charcoal canister is completely soaked i

The only way the canister gets soaked is if either the vent solenoid valve or purge solenoid valve are not working right. And they would throw a code if that is the case. Although I suppose any of the lines/hoses going to/from the canister could be a concern as well.