Ive been turbocharged for awhile now and about a month ago i installed a VAFC. Ever since the install i have noticed that during 2-3k rpms when i am putting a constant pressure on the pedal (just cruising), it drops out and acts like i took my foot off the pedal. My tach does not move and my throttle pressure does not change on the VAFC. I had resently thought it was running too lean and i richened it up but it did not solve the problem. Does anyone know what is going on /

Thanks

 

anyone?

 

check your TPS voltags to make sure they are in spec.

.5 volts at closed
4.5 volts at full open

 

im not sure how hondas are set up sence most of my experiance deals around BMWS and turbo buicks but if you have a knock sensor that pulls timing to compensate for knock. you probably do im a mechanic with BMW so i dont deal with to many hondas so i dont want to stick my foot in my mouth.

eather way, if you do you could be getting some false knock.

i had that problem for a while, my down pipe was hitting my a arm causing the computer to think that the car was detionating so it was pulling 20-30 kr i about **** my self the first time i seen those numbers flash but then i realized that it was false knock because none of the rods were hanging out of the block (2-3 degrees kr top end is "acceptable" but i dont even like that, 0 is ideal). with a quick inspection i found a broken exhaust hanger that was pulling down the dp enough so that when ever i hit bumps or dips that it would tap the a arm.

 

is it a hesitation or a complete loss of power. if its hesitation then that cant really be fixed. its partial thortle tunig right around vacum to boost transtion and the vafc cant really help you out there. i had the same problem

Landon

 

if its hesitation a stall converter can sometimes help a local guy here with a 10 second gn had that problem, he jumped to a higher stall and it fixed it but sence im assuming that your all manuals that bit of infos does a whole lot of good

 

Its called the hack buck it cuts out and then right back in making the car buck.
When I was using the vfc on 9pounds it would do the same thing I can't remember if there was a way to fix it or not or if its just something you have to live with when using the vfc..

I hate to say it but search on the vfchack and read throw the million posts I know it’s in there somewhere.



Modified by 15psi of fun at 2:46 AM 6/10/2004

 

Yeh it sounds like what you are talking about the "hack buck, i quess im just going to have to live with it until i get standalone . Has anyone else experienced this "Hack Buck" cus its really annoying..

 

I've got the same little hitch, and I run an AEM EMS w/wideband....partial throttle tip-in is tough to set up...

 

I have the same problem with my hondata.

 

i have the same problem with my stock ecu and an FMU

hmmm interesting...... im thinking its a sensor going bad.... but not bad enough to code...

 

I've been having a similar problem...... from about 2500-3000rpm where it feels like I lost all spark or all injectors at once and then a half second later it comes back.

I had a complete cutout on my spark plugs a few months back but found it was the ignitor module which I replaced so it shouldn't be that again.

I haven't checked codes so I might try that.

 

Have ANY of you checked your TPS voltages like I said? These all sound like the TPS sensor being out of spec.

Check voltages...if they are out of spec get a new throttle body w/ TPS and install...should take care of your problems.

When TPS voltages are out, this will affect TIP IN, Boost Transition and Open/Closed Loop transition, Deceleration enleanment and a injector shut off (while coasting over 1100 RPMs)

It doesnt matter which form of fuel management you are using either. Seems like the gamut has been covered here. (FMU w/ stock ECU, the Hack, Hondata, AEM EMS). All of you are experiencing same to similar problems.

CHECK YOUR TPS!!!

 

Hondata has addressed this issue here:

http://www.hondata.com/techhes.html

 

yes i have checked the tps voltage over and over and over again....

its within spec .48-.49 closed and 5. full throttle.... i even tried adjusting it alittle to see if it would change the problem... i made it .49 - .50, no change....

and yeah hondata may have adressed that issue, but i dont have hondata, and neither does "Mildly interesting" he has aem ems.

 

My car does that same thing. It is a common problem when running the hack.

 

I got that problem too . . . accept when I first ran the hack i never did have that problem, only recently did I start having that problem. I guess i'll be checking to see if my TPS is in spec later today.

 

Check it on the vafc, and it read .40-45 closed throttle, flucuated, and it read 4.40 open throttle, close enough? or is that my problem...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drvfast &raquo;</TD></TR><TR><TD CLASS="quote">My car does that same thing. It is a common problem when running the hack.</TD></TR></TABLE>

there are two people on here that arn't running the hack....

maybe its an issue that goes for all of them... how bout this since no one can get past the hack thing....

why does the hack cause this hicup? maybe the cause can give some insite to others that arent running the hack......

 

If you are leaning out the mixture at part throttle with the VAFC the ECU is seeing a lower MAP voltage than it normally would (Possibly running bigger injectors?)... below a certain MAP voltage the ECU cuts fuel because it thinks you are decelerating and in heavy vacuum... That would be my first guess here...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HRTuning &raquo;</TD></TR><TR><TD CLASS="quote">If you are leaning out the mixture at part throttle with the VAFC the ECU is seeing a lower MAP voltage than it normally would (Possibly running bigger injectors?)... below a certain MAP voltage the ECU cuts fuel because it thinks you are decelerating and in heavy vacuum... That would be my first guess here...</TD></TR></TABLE>

hmmm ok that makes sense for the hack...

now for me my map is about 10inhg when this happens... so its not seeing heavy vacuum....

but doesnt the ecu compare Map and Tps signals for the fuel..... so the Tps is part of the equasion too right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pornstarSR &raquo;</TD></TR><TR><TD CLASS="quote">
but doesnt the ecu compare Map and Tps signals for the fuel..... so the Tps is part of the equasion too right?</TD></TR></TABLE>

ECU compares Map & RPM...and takes consideration of Delta T (change in TPS), & IAT

If your problems are only when you are getting on or off throttle, the issue has something to do with your TPS, most likely.

The only other thing the ECU looks at TPS for is whether to be in OPEN or CLOSED loop. Above ~80% throttle, the ECU goes into OPEN loop.

 

hmmmmm ok..... this only happens at about 20% on throttle.....

the iat is no plumb'd into the intake pipe at the moment... but it is connected to the harness, maybe thats it...

ive checked the tps voltage many times... i would hate for it to be that... but im not saying it isnt... cause it can be, i have had stranger things...

i wish i could find someone that says "i had that problem i changed (blah blah) and it fixed it..." so i know for sure...

but i know how these things are, there not that easy

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pornstarSR &raquo;</TD></TR><TR><TD CLASS="quote">hmmmmm ok..... this only happens at about 20% on throttle.....

the iat is no plumb'd into the intake pipe at the moment... but it is connected to the harness, maybe thats it...

ive checked the tps voltage many times... i would hate for it to be that... but im not saying it isnt... cause it can be, i have had stranger things...

i wish i could find someone that says "i had that problem i changed (blah blah) and it fixed it..." so i know for sure...

but i know how these things are, there not that easy</TD></TR></TABLE>

Yeah its never cut and dry, especially with a turbo car. In your case, I would definitely find a way to get the IAT sensor mounted on one of your charge pipes close to the IM. On my car, its mounted to the IM stock.

At 20% throttle though and at low loads...I dont think the ECU is going to need much input from IAT, so I'm not sure it would make a noticeable difference.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mildly interesting &raquo;</TD></TR><TR><TD CLASS="quote">I've got the same little hitch, and I run an AEM EMS w/wideband....partial throttle tip-in is tough to set up...</TD></TR></TABLE>

Same here and im running the AEM EMS with a Techedge wideband..