i have a 94 dc2 with ls/vtec set up. skunk2 stage 2 cam shafts. ctr internals, VIRGIN p28 ecu, exedy stage 2 clutch with fidanza flywheel.

the problem is that im using a lot of fuel, i drive about 40 miles one way to get to work and its all high way, but ill end up using almost 1/4 of a tank, i use 91 octane.

i've had this car for about 3 weeks and i got it from someone who wanted a turbo so he thru in a walbro fuel pump and put on some ctr fuel injectors with an AEM fuel rail.

so i guess my question is that even with a high flow fuel pump, can i save on gas by using a pressure reg? there is a gauge attaced to the rail but doesnt work correctly, always reads differently. i believe the correct pressure is supposed to be around 32? not too sure, but the gauge almost always reads 40 or sometimes a little higher.

im at work and do not have the car with me so no pics, dont matter tho cuz everything is pretty self explanitory.

thanks in advance

 

so let me get this right, you're using a ecu that was ment for a sohc engine and your wondering why you're using a lot of gas on a LS/Vtec?

 

im not an idiot...i know the p28 isnt "right" for the car but its more suitable than the p05 automatic sohn non vtec ecu the guy tried to give me with the car.

i just want reassurance that the ecu is throwing the fuel pressure off or is it the pump...or a mixture of both.

its kind of hard to find a virgin p72 right now, im not having any luck. i dont want to chip my p28 either.

 

yeah, it's highly more likly that the p28 is compensating and giving you a really rich fuel mixture.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stevew84 &raquo;</TD></TR><TR><TD CLASS="quote">i have a 94 dc2 with ls/vtec set up. skunk2 stage 2 cam shafts. ctr internals, VIRGIN p28 ecu, exedy stage 2 clutch with fidanza flywheel.

the problem is that im using a lot of fuel, i drive about 40 miles one way to get to work and its all high way, but ill end up using almost 1/4 of a tank, i use 91 octane.

i've had this car for about 3 weeks and i got it from someone who wanted a turbo so he thru in a walbro fuel pump and put on some ctr fuel injectors with an AEM fuel rail.

so i guess my question is that even with a high flow fuel pump, can i save on gas by using a pressure reg? there is a gauge attaced to the rail but doesnt work correctly, always reads differently. i believe the correct pressure is supposed to be around 32? not too sure, but the gauge almost always reads 40 or sometimes a little higher.

im at work and do not have the car with me so no pics, dont matter tho cuz everything is pretty self explanitory.

thanks in advance</TD></TR></TABLE>

Bolded statements are what you need to address and research.

You should have that virgin p28 tuned for your application, that's the major reason why your getting crappy gas mileage. I'm assuming that fuel pump is a 190 or 255 lph, that's overkill for an all motor setup, but that and the injectors need to be tuned for your setup. You probably running super rich right now, how does the car run?
Think about your setup for a minute. You have a stock ecu that was meant for a stock pump and injectors. Then you installed a high flow pump and higher cc injectors. Obviously you're gonna waste more gas.
Also, don't adjust the fuel pressure, have the tuner do that. Once you get it tuned you should see an improvement in you MPG.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stevew84 &raquo;</TD></TR><TR><TD CLASS="quote">im not an idiot...i know the p28 isnt "right" for the car but its more suitable than the p05 automatic sohn non vtec ecu the guy tried to give me with the car.

i just want reassurance that the ecu is throwing the fuel pressure off or is it the pump...or a mixture of both.

its kind of hard to find a virgin p72 right now, im not having any luck. i dont want to chip my p28 either.</TD></TR></TABLE>

Why on earth would you prefer to run a stock p72 with a cammed motor vs. chipping the p28 for your setup? Don't ask for help then if you're not willing to take sound advice.

 

hmm...only one way to find out...

whenever i do find a p72 i'll end up posting again.

thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stevew84 &raquo;</TD></TR><TR><TD CLASS="quote">hmm...only one way to find out...

whenever i do find a p72 i'll end up posting again.

thanks</TD></TR></TABLE>

Stock p72 with a cammed motor = thread "why does my car bog when I hit vTAK?"

 

an obd2 p73 would have maps closer to what you need. you shouldn't waste more money on a new computer when you can get the p28 chipped and tuned and have a badass motor. what manifold are you running?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stevew84 &raquo;</TD></TR><TR><TD CLASS="quote">hmm...only one way to find out...

whenever i do find a p72 i'll end up posting again.

thanks</TD></TR></TABLE> WHY? Chip your P28, you're already half way there... you just need the chip. Rather than getting a P72 only to realize that it runs like ****. Everyone is giving you the answer you're looking for, and yet you're still rejecting everyting that is said. I understand you wanted reasurrance that the ECU was the problem in this, but, it's still not going to run right with a P72.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ruffrhyder &raquo;</TD></TR><TR><TD CLASS="quote">

Why on earth would you prefer to run a stock p72 with a cammed motor vs. chipping the p28 for your setup? Don't ask for help then if you're not willing to take sound advice.</TD></TR></TABLE>

x2 this post in nuts. all this guy needs to do is chip his p28 and spend some time with a decent tuner and your mpg will return along with more HP. seriously, what aren't you getting? i mean do you seriously think that your ecu magically knows everything it should do with this modded motor? if you want to keep a stock p28 get rid of your engine and find a stock SOHC. then it will actually be correct.

 

get your p28 chipped and tuned with the injectors.. it will solve all of your problems. Right now you are running MAJORLY rich lol

 

What size injector are using?...If stock ones are being used could be bad in a stuck open postion and are just dumping fuel. Another thing can be a bad FPR, check to see how much PSi it is set too, if you are running OEM, it's bad. There is other things that could be wrong...but you need to be more specific about what you are running?

 

sorry for lack of posts...i just wanted to know what my options were, if chipping is the way to go then fine. i knew the p72 isnt exactly tuned for my setup but its dohc...thats as far as i thought.

i figured it would be better suiting than the sohc.

since its an lsvtec dont i need a base map for gsr, then turned further from there? also i will probably revert to stock injectors and pump.

 

you can keep that fuel pump and injecters in there just take your virgin p28 out have it chipped then take it to get tuned. It doesnt matter what motor you have in the car every setup is different you need your own custom map done for the car to run properly and perform right.