slammedef06

UPDATE!!! changed oil and filter, installed and gapped fresh iridium plugs, installed new fuel filter and pcv valve and cleaned o2 sensor with seafoam... drove the car home and it was fine for a while until about 2 minutes from my house it started to HESITATE REAL BAD, BACKFIRE AND ALMOST DIE while i was at like 3-4000 rpm in 2nd and continued in every gear... now it definately improved a little for a while but now it feels as though the engine isn't getting fuel or something. here are the only possibilities left that i can think of... bad o2 sensor, bad fuel pump, or bad injectors! please help. thanks


1995 honda prelude VTEC 5spd 148k miles but well maintained... i just took it to a local shop today and no one knows what the problem is. STOCK VTEC ECU

stock except for intake header exhaust...

The car throws no CEL codes of any kind. i even jumped the diagnostic connector but the CEL goes on for 2 seconds solid and goes off.

Problem # 1 = when i tap the gas pedal i hear a suction noise followed by a pop. the car will sometimes even rev up on its own!
(not my intake, i took it off and you still hear it from the throttle body area...)

Problem # 2 = bad hesitation under regular driving conditions, holds back and finally all the power kicks in at once, its getting pretty bad. happens in any gear especially going up hill. backfires alot too.

(replaced spark plugs, wires, distibutor cap + rotor, fuel filter, header, cat, air filter, exhaust, all about 2k ago...i do regular oil changes and have done fuel system cleaners too.)

WHAT I THINK THE POSSIBILITIES ARE: BAD ECU i was recently putting in my audio system and crossed two wrong wires and smoke came out from my head unit, i think i may have shorted out the ecu...IS THIS POSSIBLE? AND HOW COULD I TEST IT?

hesitation was happening prior to header and cat install.

PLEASE IF YOU HAVE ANY HELP FOR ME I WOULD GREATLY APPRECIATE IT.


Modified by slammedef06 at 7:54 PM 8/14/2006


Modified by slammedef06 at 7:55 PM 8/14/2006


Modified by slammedef06 at 7:55 PM 8/14/2006


Modified by slammedef06 at 7:55 PM 8/14/2006


Modified by slammedef06 at 7:56 PM 8/14/2006


Modified by slammedef06 at 7:56 PM 8/14/2006

ECX

vaccum leak?
idk man

SKDRCR

swap it with a good ecu see what happens,

are you sure the suction sound isnt the air intake?

if not, you have a vacuum leak somewhere.

slammedef06

its definatley not my intake cuz i've had the intaake in for months and it just started, also i took out the whole intake and you still here it up near the throttle body...you don't think its the idle air control valve right? the idle is fine its just when you rev it slightly you get the sucking and then a slight pop.

i'm gonna try to find someone to swap ecu's with and double check for vaccum leaks.

thanks

phateless

x3 for vacuum leak. double check all your vacuum hoses. there is a wiring diagram on the underside of your hood. also, check all the hoses and gaskets on your throttle body/intake manifold. this DEFINITELY sounds like a vacuum issue to me. my accord did the same thing when the hose that connects the intake arm to the throttle body slipped a tiny bit out of position. it LOOKED like it was properly in place, but it wasn't. caused bouncing idle, surging power, delayed throttle response, all sorts of bullshit

y0whuddupb

the first problem sounds like a vacuum leak as everyone is sayin..


the second problem sounds like bad timing. check if you might have jumped a tooth. also could be a bent vavle that causes the hesitation.

slammedef06

rechecked the vaccum lines...everything is plugged up or going somewhere. i dont know what to do.

whats the easiest way to check the timing? also how would i know if i have a bent valve and how could that have happened anyway? thanks

slammedef06

any other ideas?

slammedef06

also do you think i couldve fried the ecu partly when i was installing my audio system and crossed the wrong wires? smoke did come out of the deck and i blew the backup fuse.

liukangus

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammedef06 &raquo;</TD></TR><TR><TD CLASS="quote">also do you think i couldve fried the ecu partly when i was installing my audio system and crossed the wrong wires? smoke did come out of the deck and i blew the backup fuse.</TD></TR></TABLE>
I highly doubt that your ecu went to hell. If you only crossed one pair of wires and the fuse blew out, then the fuse did its job and protected stuff from frying, unless you were doing all this wire crossing while the car was running. Once again, check those vacuum hoses. It might not be a bad idea to check the timing as well. I'm surprised you aren't throwing any CEL codes.

Edit: I'm an idiot. The fuse didn't protect anything if you saw smoke coming from the rear of your head unit. But, I still think your ECU is in good shape. It's not like a burnt out ECU will make a sucking sound. It shouldn't make any sound!

phateless

just because all your hoses are connected doesn't mean they're connected correctly. check against the routing diagram under the hood. sounds like the short-ram was installed incorrectly. re-install the stock airbox/filter and see what happens. at the very least it will eliminate a variable.

tkevin07

Ur ECU wnont make a vacuum noise, try taking off ur brake booster line and see if it has an effect, if its still doing it, its most likely leaking there, if u take it off and it gets worst the problem is somewhere else, i kno the brake booster has high suction power
good luck!

slammedef06

no i'm not saying the ecu caused the suction noise but maybe the hesitation, etc... when i installed the new header a stud on the bottom drivers side did come out but i just tightened the rest up and it was fine for a while, u think this could be causing the noise?

i know it isnt causing the hesitation cuz it was happening prior to the install. also the intake is a cold air and i installed it okay, plus its been in there for months and the sound just started days ago but i double checked it anyway.

phateless

when my short-ram on the accord caused a problem it had been on there for over a year, and then one day it got loose. **** happens.

slammedef06

thanks, but i mad sure everything was tight and i even went back to the stock one to try but its not that...it seems the sound is coming from inside the throttle body, maybe coming from the missing header stud?

slammedef06

i tried just screwing the header stud back in because its fully intact but it wont grab, any ideas?

tkevin07

JB weld? haha

phateless

longer bolt with the same threads?

XRSLUDE

I HAVE THE SAME PROBLEM...I TO NEED SOME HELP...LMK. IF YOU GET AN IDEA ON WHAT TO DO...THANKS!

Finest

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammedef06 &raquo;</TD></TR><TR><TD CLASS="quote">i tried just screwing the header stud back in because its fully intact but it wont grab, any ideas?</TD></TR></TABLE>

You can try to retap the hole for a slightly bigger stud. Or try some inserts.

slammedef06

UPDATE: FIXED 1 PROBLEM... no more sucking noise with pop when i rev. a couple weeks ago i was cleaning up my engine bay and i bought a pack of vaccum caps for a couple places like where i took out my cruise control, and i plugged up something i thought was a vaccum leak on the intake manifold, there is a little unit with a tiny pipe pointing upwards it looks like part of the cruise control unit but when i was troubleshooting today i uncapped it and there is no more noise. but i still have a BAD HESITATION problem...is it really necessary for me to put that last header stud in? all the others are on real tight?

slammedef06

updated please help thanks

phateless

sounds like you're on the right track. if you removed your cruise, than there are probably a lot of vacuum lines that need to be re-routed. consult the routing diagram under you hood.

slammedef06

well there were only two vaccum liness but i plugged them and its been fine for like 3 months but now all of a sudden i get this...would just an o2 sensor cause this bad hesitation backfire and almost stall?

phateless

if there's something that wrong, you should be getting a code. with what limited information we have, it's hard to tell.