the car is a 95 Honda Civic LS 5 speed.

at first the car the car had a bad bucking problem up to about 3500 RPM, now it doesnt buck but there is no power at all. WOT it barely moves. then it'll snap out of it to its normal power.

all of this has happened in the last week and it came out of nowhere(it didnt gradually get worse). now i know the IACV is weak cuz when the A/C is turned on or the wheel is turned the idle starts to struggle but the problem still happens at WOT, part throttle so that shouldnt be related.

now i know it is NOT the PCV valve, it is NOT the o2 sensor, it is NOT the TPS. i recently replaced the fuel filter due to something unrelated to this. the distributor/wires/plugs were replaced less than 6 months ago. and there is no check engine light.

im starting to lean towards the fuel pump going out. any ideas/suggestions?

 

Subscribed cuz I am dealing with this mystery as well.

 

there no CEL which makes this so much harder. i cant think of what else it would be, just not enought fuel pressure maybe. my stupid gauge only goes to like 10psi

 

bump... anybody...

 

This is an IAVc/ FITv leak problem. (for the Bucking problem)

Sometimes the FITv gets stuck in the open position, causing a vaccum leak that throws off how the motor operates under 3500 rpm, giving it a 2-step like pulse if you rev it and hold it under 3000 rpm. I solved this problem by cleaning and repairing the FITv unit. This can also be traced to a bad IACv in some cases.

Not sure about the power issue, but if the bucking one returns, what i listed is the common solution.

Check all the grounds, even try a different ECU.

 

the vacuum was over 20hg at idle

check the grounds on what?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ehop &raquo;</TD></TR><TR><TD CLASS="quote">the vacuum was over 20hg at idle

check the grounds on what? </TD></TR></TABLE>

Make sure tranny ground is tight, and the block ground. A normal idle vaccuum (for my D series at least) is around 24-23 HG/cc. I noticed when i had a vaccum leak it was around 21 to 19 Hg/cc's.

 

yea it was 23hg, i'll check those ground when i get home from school today, thanks

 

the tranny ground was good and clean. the ground to the valve cover it fine too. where is the one to the block? should i get a couple feet of 10 gauge wire n run some mor grounds?

i cleaned the fitv and it still acts up

 

I just had this same problem. before you do something expensvie like repacle the fuel pump, check all your grounds. I had 12 gauge wire for my grounds, so i took them all off, and replaced them with 8 gauge wire, and then iwent ahead and threw on an extra ground wire to the cylinder cover. it's running great. for less than $10 try that first, if that doesn't work, check your injectors maybe.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ehop &raquo;</TD></TR><TR><TD CLASS="quote">the tranny ground was good and clean. the ground to the valve cover it fine too. where is the one to the block? should i get a couple feet of 10 gauge wire n run some mor grounds?

i cleaned the fitv and it still acts up</TD></TR></TABLE>

i just read that, go thicker than 10, get like 8 or bigger.

 

Try replacing your spark plug wires with new OEM ones...had this problem on a subaru with cheapo wires- champion I think. Plugs would be good too.

 

i'll try the 8 gauge wire. i dont think its ignition related cuz there is no CEL