at idle my car makes a "wub wub wub" noise. my RPM hobbles around in between 800 and 1100. as soon as you hit the gas it goes away. before you start reaming me with easy answers to my problem, lemme tell you what all I've done to try and correct it: new plugs, wires, new Iac vavle, Pcv valve, replaced stock cams and gears, checked and replaced all vaccum lines except EGR, replaced stock Intake mani., replaced stock Throttle body and replaced stock coil for MSD coil. and my comp. is almost perfect in every cyl. All of the stock things I've replaced were either new(if small) or off another 420A that didn't have the problem. I have the Head off the old 420A to replace the current one, I just don't want to waste 2 hours of my time replacing it if I don't have to. which is whyI think it maybe a clogged EGR system? oh yeah I have one easy question too: Would installing a High flo cat throw a CEL? thanks for any and all input!

when i first got my car i had a similar problem! my problem turned out to be a bad cam positioning sensor! maybe yours is on its way out the door!.... just a thought

LD25Delta9 said:

at idle my car makes a "wub wub wub" noise. my RPM hobbles around in between 800 and 1100. as soon as you hit the gas it goes away. before you start reaming me with easy answers to my problem, lemme tell you what all I've done to try and correct it: new plugs, wires, new Iac vavle, Pcv valve, replaced stock cams and gears, checked and replaced all vaccum lines except EGR, replaced stock Intake mani., replaced stock Throttle body and replaced stock coil for MSD coil. and my comp. is almost perfect in every cyl. All of the stock things I've replaced were either new(if small) or off another 420A that didn't have the problem. I have the Head off the old 420A to replace the current one, I just don't want to waste 2 hours of my time replacing it if I don't have to. which is whyI think it maybe a clogged EGR system? oh yeah I have one easy question too: Would installing a High flo cat throw a CEL? thanks for any and all input!

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A Clogged EGR valve or recirculation tube would not effect your idle, but if the EGR valve is stuck in the open position it will seriously effect idle and will be getting horrible vacuum readings aroung -10 in hg.

My advice would be pull the EGR valve from the head, then take the metal gasket and a coke can and trace the gasket on the coke can. Cut it out, but do not cut the hole in the middle of it out. Your going to block the EGR system with it. Put your solid gasket in place of the EGR gasket and fire up the car. If your idle is fixed then the EGR valve is stuck open. Keep in mind an EGR valve stuck open will cause horrible idle, but will not be noticeable while driving. Sounds alot like your issue here.

freaking awesome. I had forgot to mention that it also only does it when the car is at Normal Op. Temp. and you were right about it only doing it at idle as well. I'm gonna do that today an see what happens. I'll let you all know. thanks.

so it wasn't the EGR. I'm gonna price a CPS and go from there. any other suggestions? I've got my DVD camera charged so I'll try and get some samples for you all to listn to and see. I'll post soon.

You say that you have replaced the Cams and Gears...Is your timing ON correctly?

What type of cams are you running? stock?

Post up some video or at least some audio so we know what you are describing.

I had this problem and it was a bad egr valve stuck open..

here you go guys. I've got another one if you need it. just lemme know.MySpaceTV Videos: problems by Torture of the Masses T.O.T.M.

I've got one more I'm going to post. it an under hood video. it takes me a while to get them uploaded at work. sorry so sporadic.

Have you looked at your timing marks? If the car isn't throwing any new cel lights for you then take a look to make sure all the timing marks are alright.

My timing is dead on. stll not sure what it is....there's no knock at all in the head either. I figured that if it was in the block or head, my performance would be affected from Idle to redline and everywhere in between. but as far as I can tell it's not. just at idle. so outside of replacing my head, the only other thing left is the Camshaft position sensor.right? Caue it's not the EGR.

bad news....It's not the EGR at all. I replaced that just to be sure and am running it stock now. I also replaced the Cam pos. Sensor as well. that didn't do it. I aslo did a comp. check just for fun. 3 of my cyl. are at 190 psi. and the fourth is at 205 psi. the head is the only thing left. it's a 95 N/T Longblock and tranny running on 98 every thing else. I replaced all the sensors according to the wiring harness plugs. the only thing that has not been replaced is the Head and all its internals minus cams and gears. (stock) I figured that with a comp check, it would show me if there were any major things wrong that would cause such a funny idle. I am going to replace the head once I get my spare cleaned and a new head gasket. I'll let you know how it goes after this week end. I'll be checking this novel periodically before the 4th to see if anyone has ESP and knows exactly what's wrong. the head is the only thing left.................AAAAARRRRRGGGGHHHHHH!!!!!!!

what you could also try is some combustion chamber cleaner. my car was doing almost the same exact thing. and it fixed it.

I ran a whole can of sea foam through my vaccum line and it made it less prominent but it still does it. I'm still stumped as to what it could be. like I said I've got a spare head but it still needs cleaned badly, and an upper gasket kit to rebuild it with. lots of carbon build up. nothing a wire brush and some sea foam can't take care of. just trying not to have that hassle until I get it stroked, bored...etc...

LD25Delta9 said:

I had forgot to mention that it also only does it when the car is at Normal Op. Temp.

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Replace your coolant temp sensor (CLT). Of the two below the radiator cap, it's the one with the multi-wire going to it. The other one just feeds the temp gauge.

$25 or less at Autozone.

I replaced that when I did the engine swap. It had the same problems when the engine was in my talon.

This may sound weird, but its a 100% true story. When I first rebuilt my engine, when i fired it up it sounded like I changed to a higher lift cam, something with more overlap. It would just lope at idle. wub wub wub wub. I knew a long rod bottom end wouldnt effect the idle so I started trying everything to fix it. I ended up changing my ASD relays cause I had an extra set from an automatic car laying around, I just didnt use the transmission plug of course. It immediatly smoothed out my idle and I never had a problem since . Still running that ASD relay set from the automatic car as a matter of fact. Every once in awhile you get on of those weird ghost problems. I havent heard of a person having my same problem since.

so I should check my ASD relays huh? I'll check them out. I can tell you my talon was a manual, and so was the 98 eclipse that I dropped everything into. just had a different ECU. My talon's tranny blew up on me and I replaced it but kept the same sensors to put into the new one cause it didn't come with any but the tranny that came with the 98 was in good condidtion. so I'll do some swapping this weekend and let you all know what I come up with. thanks 4uh8rs you've been a big help man. and so you know my vac test came up in between 5 and 10. should have been around 15 though right?

15" isn't great vacuum, either, 16-18 would be better.

Start looking for your vacuum leak.

Locke said:

15" isn't great vacuum, either, 16-18 would be better.

Start looking for your vacuum leak.

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Agreed, obvious vacuum leak here and because of the slow idle associated with it. I would bet you the vacuum leake is after the MAP.

I've put a steth on it to try and find a vaccum leak and can't find jack. no airy noises coming from anywhere, HOWEVER: I checked my CLT and it was the same one off of my talon. SO DR1665 you may be right. I looked at the assembly I took off the talon and it had a missing sensor. After I do a tattoo today to make some bucks, I'm stopping at auto zoo to get a new one and I'll let you all know. but still vaccum leak is apparent just can't find it. I've got my head cleaned and ported, just need new gaskets. anyone think it'd be worth it to replaced? other than the obvious reasons.(ported Vs. Non-ported) maybe a clog somewhere? think a stick of dynamite might help?

Do a smoke test to help you find the vacuum leak then. Put a balloon or something tight over the throttle body so it wont leak. Go buy a big old cheap cigar and blow smoke through one of your vacuum lines preferabbly in the intake manifold. Just use a vacuum plug and plug the hole from the opposite end you pulled the line of course.

I replaced the CLT...nuthin doin. I even reset the ecu and nuthin. gonna do a smoke test today. probably nuthin.

LD25Delta9 said:

I replaced the CLT...nuthin doin. I even reset the ecu and nuthin. gonna do a smoke test today. probably nuthin.

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With your vacuum reading, youll find something if you do it right. Theres a leak and if you blow enough smoke yourll find the leak.