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This past weekend at Moroso I noticed that my car seemed to feel wierd @ idle....I have not made a run down the track yet.....I thought it may have been the slicks with little air pressure in them giving me a bouncing feel, so I never thought anything else of it.
Last Night I was getting gas but before I got Gas I listened to my car and the exhaust.......The exhaust was making a Blump.......Blump..Blump.....Blump sound, however, it's only at idle..I got my girlfriend to keep the rpm around 1200-1500 on there was nothing, it sounded normal. The car seems to run fine @ WOT!
There is NO flucuation in the rpm at idle either..........Any Solutions????????????
Thanks!
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what else do you have done??
motor mounts, test pipe,...???
any of these could do it....
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1996 GSR 4dr....221 hp with a 6psi JRSC
Heres how I pay for all my goodies
POWER
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My 96 GSR w/JRSC would idle with a "Baah...Baah...Baah..." sound a little more frequent than 1 second after it threw a code (14 I think).
Once I got the code I would get the pulsing in the exhaust and it ran like crap until I reset the ECU.
The culprit was a vacuum leak near the IAC.
Try reseting the ECU.
Greg
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Hey Jason I guess you got your studs fixed....damn what a pain huh....you really lucked out with that tow home!!!....and you didnt miss out on anything beacause it rained out on sunday....well theres august to look foward to now!!....and the Nira event in september....hopefuly by then I will have swapped the new motor into my teal civic and I will be ready to race!!
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John
Hey what you got in there??(In a redneck voice)
Oh just a Intake, Header and Exhaust http://www.hostboard.com/ubb/biggrin.gif
B18C1 powered Civic EX Coupe
'92 Civic VX Hatch...being prepared for MAD BOOST!
[This message has been edited by CivicR (edited June 15, 2000).]
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Don't mean to get you scared but, it sounds like a bent valve or a misfire, the only time you hear it is a idle and your car feels like it has a lumpy a$$ cam in it.
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I dont have a test pipe or motor mounts....I did try to re-set the ECU and it did nothing.
I did break a injector and got one from Mark Browning at the last NIRA event in April.....COuld that injector be Bad? It was from a 95 Integra.
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I forgot to say: The exhaust does do it at idle but sometimes is does it back-to-back then it may stop for a second or two, sometimes up to three, if it was a bent valve, would it run like this periodic intervals? And still have no power loss at WOT....least I cant feel any, and my a$$ is sensitive to power!
If I had a small hole in the piston it wouldn't run right...Right?
A bent cam, It should do it though the entire RPM range?....
A bent valve, a power loss and it should also have an affect on the entire RPM range?
I guess I have to do a compression test then a leak down.
Does the above make sense?
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First, try holding a flat piece of cardboard over the end of the tailpipe. This will amplify the misfires and make it easier for you to detect them when the RPMs are a little higher than idle, as you said the exhaust sounds normal above 1200 RPM, maybe it isn't.
Before you start worrying about major mechanical problems try the following:
- Check for vaccuum leaks.
- With a vaccuum gauge verify that you've got around 20" vaccuum at idle.
- Check valve clearances. If they're too tight, the vaccuum will be low and there might be an occasional misfire at idle.
- Check the cam timing. If they're off by much it will affect vaccuum and idle quality.
- Check your spark plugs. See if there are conductive deposits on the insulators (if you've been using octane boosters for example), or they're loading up, etc. Too small a gap will also cause the idle to be rough.
- Check the condition of the plug wires, cap and rotor.
- Check the fuel pressure at idle. If it's way off the idle will suffer.
- A faulty fuel injector can cause a rough idle. The easiest way to check them is to swap them as a set with another set that's known to work properly.
I doubt there's a bent or burnt valve as the misfire would probably be more consistant. But just to be sure, you could run a compression test. If you suspect valves and the compression's good, there's no need to run a leakdown test.
The other mechanical problems you suggested would have a much more significant impact on the way the engine runs (and sounds) than what you've described.
Also, the gas itself can cause problems. On rare occasions it's possible to get a tankfull of gas that's "not right". Believe me, it's happened to me twice, though not recently, and it sent me on all sorts of tangents trying to troubleshoot it. However, in my experience "bad gas" not only affects idle, it affects performance throughout the engine's operating range. But that's just my experience. If you haven't already done it, try driving through the tank of gas and filling it up again to see if that solves the problem.
[This message has been edited by rjaffey (edited June 15, 2000).]
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Do you have an aftermarket exhaust? When I installed an apexi exhaust on my civic the flange near the gas tank was vibrating against the tank at idle.
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RJAFFEY:
Thanks for the info.....Im at school so I have to wait to go to my parents house to get my tools and compression gauge. Personally I dont think I have a bent valve.....
You mentioned about octane boost....I was running 103 octane in the car at the track. but I went there and filled up (one gallon) then got into the staging lanes. I dont think the 103 would get to the engine that quick......I guess I have to wait till I get to my parents house before I start elimiting anything!
No, I dont have an exhaust.....YET!!!!
Thanks for the suggestions...Ill try them!
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I didn't mean high octane gas. I was referring to octane booster additives. Some of them ruin plugs after a while.
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My car threw a code #72....That is the cylinder that I have that Mark Browning injector in.....I think that is my problem!!!!!...I hope and not a bent valve or ring or something!
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