1990 Integra LS Performance at half a tank

**b18cfreak** · 11-12-2008 05:43 AM

Ok, i'm not sure if this is just a random thing with my particular car, but here it is.

When my car's fuel guage is sitting at about 1mm above the half way mark, untill it gets down to about 3mm past half way the thing absolutely rips. Like i'm talking it is a very big noticable difference.

When i have a full tank (quarter or more) it feels exactly the same as when i have an empty tank (quarter or less). Now i'm no noob to cars so i know the age old less fuel = less weight, but that just isn't what this is and like i said an empty tank seems to make no difference to a full tank. The power i'm seeing is the car transforms into an entirely difference beast. It feels like it gains torque throughout the entire rev range, and i'm talking it feels like it's suddenly gone from being a 1.8 to a 2 litre kinda difference. And it just spins up so damn fast and completely nails you. Second gear takes like 2 - 3 seconds to rev out where as if i had a full tank or empty tank it'd take like 4 - 5 seconds to rev out.

This has been true with my old stock standard motor, my current motor (b18c) and with the old ecu, the type r ecu i had for a bit and my current gsr ecu with hondata s200. So i'm kinda left with something to do with the fuel delivery. Maybe the fuel pump, the way the tank is something along those lines. So i'm just curious to see if any other Integra drivers feel the same as i do and to what extent.

I just want to clarrify that this is not some slight feels a little better, this is a pretty big difference. I'm posting now because just then on my way to work the needle is exactly half way and it was screaming better then ever, completely blew me away with how hard the thing is going right now.

Any suggestions as to what it might be also would be great because if i can get it to go how it went this morning but all the time. Cheeering !

Thanks guys

Scott -

**Jon_51** · 11-12-2008 12:22 PM

is there a fuel filter in the tank of a da?

**Jon_51** · 11-12-2008 01:03 PM

Nevermind I just looked in the manual. there is a filter in the tank aswell. I'm guessing it'd be fuel delivery related.

**dsp26** · 11-12-2008 01:17 PM

sure it ain't your butt dyno tickling ya? you can't really make the assumption without verifying on a dyno...

i lost 10wkw from upgrading IM/TB and my arse told me it was all sweet and making more power.. go figure

**IZY-10** · 11-12-2008 10:13 PM

Originally Posted by dsp26

sure it ain't your butt dyno tickling ya? you can't really make the assumption without verifying on a dyno...

i lost 10wkw from upgrading IM/TB and my arse told me it was all sweet and making more power.. go figure

Your but dyno must need re calibrating

**b18cfreak** · 12-12-2008 05:38 AM

Originally Posted by dsp26

sure it ain't your butt dyno tickling ya? you can't really make the assumption without verifying on a dyno...

i lost 10wkw from upgrading IM/TB and my arse told me it was all sweet and making more power.. go figure

I'm 100% sure that the car accelerates way harder @ half a tank. Like with this difference there is no possible way that my butt dyno is tricking. Like i said, this increase is insane. It's like take a hot day, drive in the middle of it with the aircon on and 3 passengers in the car, then take all the passengers out, remove the aircon completely and have ur car run in the middle of the night with ice cooling in the intake. That is the kind of difference i'm talking about.

I mean, the car goes really well normally regardless, i'm just really baffled by this and would really like to know what the hell is going on lol!

ps. I'm not rich enough to go get it tested on a dyno when ever i feel like it haha.

**slidetaker** · 12-12-2008 06:52 AM

Don't know if this is related to your situation, but I share this observation with you anyhow.

Every weekday, I have to travel up this steep hill with 5th gear doing 60km/h.

Starting of the week, full tank of petrol, I can maintain the speed with half throttle and even slowing accelerate with flooring the throttle...

End of the week, near empty fuel tank, I have to flooring the throttle to maintain the speed...

Obviously, this is related to the fuel system. Pump or filters or injectors...I don't know...

**dsp26** · 12-12-2008 07:53 AM

Originally Posted by b18cfreak

I'm 100% sure that the car accelerates way harder @ half a tank. Like with this difference there is no possible way that my butt dyno is tricking. Like i said, this increase is insane. It's like take a hot day, drive in the middle of it with the aircon on and 3 passengers in the car, then take all the passengers out, remove the aircon completely and have ur car run in the middle of the night with ice cooling in the intake. That is the kind of difference i'm talking about.

I mean, the car goes really well normally regardless, i'm just really baffled by this and would really like to know what the hell is going on lol!

ps. I'm not rich enough to go get it tested on a dyno when ever i feel like it haha.

oem fuel pressure reg maybe shot...

**b18cfreak** · 12-12-2008 10:57 AM

hmm. I'm going to be doing a bit of testing hopefully on sunday, I will post back with results. I'm so determined to sort this out. It would be so awesome if i could get the added performance i'm talking about to be an all the time thing.

On a completely different topic, I bought an after market bucket seat from Autobahn, it's a "Drift" seat. Apperently really popular with Skylines. I chose it because out of all the seats i've ever sat in, this one was the perfect seat for my fat ass. So any suggestions on where to take this sucka to be installed would be great.

**kikxz** · 12-12-2008 11:28 AM

but since its a b18c the stock engine should be a b18a so you should try asking the dc boys maybe they have similar issues? but like everyone said it must be something to do with the fuel system unless the A/F ratio is tweaked by the ECU to burn more petrol at half tank?? im no pro but its a suggestion/idea so dont shoot me

**kikxz** · 12-12-2008 11:30 AM

and with the seats just take off you stock rails and rebolt them into the drift seat so it stays the exact same... you just need to find the right spots to screw it on ....

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