XES

Anyone have any idea what might be causing this?



Here is a Hondalogger file with a similar occurrance:
http://homepages.ucalgary.ca/~bunryn/b2.rec


Rpm is no longer fluctuating like that....but the car hesistates and sputters past 6k rpm (see lower posts for details).


Modified by XES at 6:50 PM 6/2/2006

D-booster

looks like miss fire up top, check your wires and spark plug gap. Also make sure engine is grounded properly, hope this helps any good luck.

XES

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by D-booster &raquo;</TD></TR><TR><TD CLASS="quote">looks like miss fire up top, check your wires and spark plug gap. Also make sure engine is grounded properly, hope this helps any good luck.</TD></TR></TABLE>

Plugs are new (NGK V-power 8's - gapped at 26) and a complete grounding kit was just installed. All the plug wires also seem fine (in terms of resistance/foot). The rotor was recently replaced (and 3 different stock distributers were tried). The rotors do seem to burn or darken very quickly after being installed. Any other ideas? and how could the tps appear to be fluctuating also?


Modified by XES at 10:42 AM 6/1/2006

dcturbols

TPS may be bad. My friend had one go bad but it was weird like that, it only had problems outputting the higher voltage saying WOT.
Get a voltage reading from your TPS when it is at WOT and see if you get fluctuation

XES

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dcturbols &raquo;</TD></TR><TR><TD CLASS="quote">TPS may be bad. My friend had one go bad but it was weird like that, it only had problems outputting the higher voltage saying WOT.
Get a voltage reading from your TPS when it is at WOT and see if you get fluctuation</TD></TR></TABLE>

TPS appears solid at all throttle angles...

Could it be an ignitor problem? What about doing an ignitor bypass?

mrbsponge

yes it could be an ignitor.


have you tried bringing that plug gap down some? i mean youre using 8s so i am going to assume you make over 400+ HP, otherwise you need 7s. BUT if youre making that kind of power i would bring that gap down to like 25 or 24

prelittlelude

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

TPS appears solid at all throttle angles...

Could it be an ignitor problem? What about doing an ignitor bypass?</TD></TR></TABLE>

you said you tired three diferent stock dizzys which in that case you would have tried 3 different ignitors, unless you swaped your old one into each dizzy.

XES

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelittlelude &raquo;</TD></TR><TR><TD CLASS="quote">you said you tired three diferent stock dizzys which in that case you would have tried 3 different ignitors, unless you swaped your old one into each dizzy. </TD></TR></TABLE>

That might have been done on a few occasions I will be doing the ignitor bypass today...see if that changes anything.

And i have tried closing the gap more with no change. 8's are being used because im in the 400-450whp on pump and will be much higher on c16 (9's might be going in)

warrick

log another source of voltage. even with misfires, the pure voltage reading from your TPS shouldn't look like that.

looks like noise/ground/power issue. check for voltage drops across grounds, and make sure your alternator isn't spitting out ridiculous voltages once it gets spinning.

prelittlelude

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by warrick &raquo;</TD></TR><TR><TD CLASS="quote">log another source of voltage. even with misfires, the pure voltage reading from your TPS shouldn't look like that.

looks like noise/ground/power issue. check for voltage drops across grounds, and make sure your alternator isn't spitting out ridiculous voltages once it gets spinning.</TD></TR></TABLE>

i was starting to think the same thing, i at first assumed the car was studering so bad in the top end it was actually making hit foot move the throttle..

ignitors can be a pain in the ***.. i have seen plenty of hondas break up in the top end from bad ignitor, but i was just warry of coming to the conclusion because u said you tried different dizzys.

XES

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelittlelude &raquo;</TD></TR><TR><TD CLASS="quote">i was starting to think the same thing, i at first assumed the car was studering so bad in the top end it was actually making hit foot move the throttle..

ignitors can be a pain in the ***.. i have seen plenty of hondas break up in the top end from bad ignitor, but i was just warry of coming to the conclusion because u said you tried different dizzys.</TD></TR></TABLE>

I did the ignitor bypass for my ignition system (using the schematic for the trigger adapter circuit taken from PGMFI.org). The rpms no longer vary up and down with large load. However, the car does sputters and hesitates once the car reaches ~6000rpm.

This sputtering only happens at high rpm in 2nd gear or higher and is not dependent on the boost level (i.e. happens the same at 8psi as 15psi). I am using an MSD digital 6plus, HVC coil and MSD plug wires. AF ratios while it occurs are where they are supposed to be (~11.7-12:1).

Could it be something with my coil or digital 6plus? Any other ideas? Would the TPS readings in the on position be the same as under heavy load?

prelittlelude

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

I did the ignitor bypass for my ignition system (using the schematic for the trigger adapter circuit taken from PGMFI.org). The rpms no longer vary up and down with large load. However, the car does sputters and hesitates once the car reaches ~6000rpm.

This sputtering only happens at high rpm in 2nd gear or higher and is not dependent on the boost level (i.e. happens the same at 8psi as 15psi). I am using an MSD digital 6plus, HVC coil and MSD plug wires. AF ratios while it occurs are where they are supposed to be (~11.7-12:1).

Could it be something with my coil or digital 6plus? Any other ideas? Would the TPS readings in the on position be the same as under heavy load?</TD></TR></TABLE>

when you do a datalog you should have had your foot planted on the floor, and in that case with you foot planted there should be no variation in the TPS reading.

when did all this start happening? was it one day out of the blue?

if you think your fuel is dead on.. then i would start investigating the MSD box. ..

the only thing that really weirds me out is that if this was an ignition problem then why would duty cycle go up and down like that. I mean i know duty cycle uses rpm to calculate its value.. but it doesn't look like your rpm varries that much.. at this point with all the **** that i hear some people having with MSD boxs thats where i would investigate further

XES

Update...I ended up putting an OEM distributer back in and the rpm fluctuation is no longer there, but the misfiring/hesitation is.

To test out some possibilities, I changed the vtec crossover to 6k rpm. As it turns of, I can full throttle it perfectly to 6k with no problems at all. In light of this, I redid all of the vtec wiring, changed the whole vtec solonoid with one i had laying around and even removed the vtec pressure switch (and disabled the pressure switch in Hondata). With vtec back at 4500...the same thing happens again. Misfiring/sputter/hesitation.

Any other thoughts?

prelittlelude

so you changed to a stock dizzy , but kept the msd box in? you said changing the vtec engaugement point changed the misfiring? are you sure the plugs are gapped correctly? i notice some missing in the top end after a while of not changing my plugs and runing 11.7:1 in boost.

at this point of trying all the different distributors and having the same results i would think the msd box might be having trouble..

have any recent data logs after doing the initor bypass, and with vtec raised?

XES

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelittlelude &raquo;</TD></TR><TR><TD CLASS="quote">so you changed to a stock dizzy , but kept the msd box in? you said changing the vtec engaugement point changed the misfiring? are you sure the plugs are gapped correctly? i notice some missing in the top end after a while of not changing my plugs and runing 11.7:1 in boost.

at this point of trying all the different distributors and having the same results i would think the msd box might be having trouble..

have any recent data logs after doing the initor bypass, and with vtec raised?</TD></TR></TABLE>

I ended out taking the ignitor bypass out...because I am running 100% stock ignition (no msd box or coil). The plugs are new and are gapped low enough that they are not blowing out for sure. This problem is happening before I am even hitting 7psi...forget 25.

I will get another datalog and post it shortly.

XES

Here are two datalogs. The maps used were identical except VTEC was raised to 6500rpm in the second one. It appears on the graphs that rpm, map and duty cycle are stepped or choppy on the 1st run...which might be causing the hesitation (or are a result of it).

1st run - 4500vtec with hesistation/sputter at 5k+
http://homepages.ucalgary.ca/~...1.rec



2nd run - 6500vtec (completely clean till at least 6k)
http://homepages.ucalgary.ca/~...v.rec




Anyone have ideas what i should troubleshoot or swap next???

warrick

do you have solid fuel pressure all the way through your rev range? are you dropping out of vtec?

XES

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by warrick &raquo;</TD></TR><TR><TD CLASS="quote">do you have solid fuel pressure all the way through your rev range? are you dropping out of vtec?</TD></TR></TABLE>

Fuel pressure is solid and rising (gauge in the car) and VTEC is engaged the whole time.

XES

Problem was the wideband a/f sensor...and thus the o2 at full throttle and in vtec. The full was essentially 10:1 or richer and would not allow the car to run right.

Everything is okay now that the fuel was leaned out and the sensor was replaced.