Engine bogging/surging (FIXED - Was the CAT)
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Audacity Racing
- moron
- Posts: 4493
- Joined: Wed Dec 08, 2004 5:18 am
- Location: Knoxville, Tennessee
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Took the throttle position sensor out... It was a LITTLE dirty, but not bad at all... I cleaned it and put it back in. Checked again for any kind of vacuum leak and couldn't find anything there either. I cleaned out what little bit of oil residue there was inside the throttle body, and found no problem there. I had already swapped out the spark plugs (which the last ones looked alright anyway...) No change. Tried my old set of spark plug wires just to make sure that the set I bought last year wasn't the problem (the set I used to drive to the auto parts store to buy the newer set)... No change in the system. I was going to go get the newer set replaced under their 5 year warranty, but I didn't think I was going to make it all the way there, so I turned it around and limped it back to the house. I suppose it's possible that I could have the same exact result from two sets of bad wires, but I doubt it... seems like I would have had some kind of other result or at least a slight change or something. I also swapped out the alternator belt since it had been squealing at me (which now it doesn't squeal or anything but who the hell cares about that since the only thing I can do is idle the damn thing or limp it around all herky jerky).
I suppose the next step will be to convert the air intake back to the original air box setup instead of the short ram I've been using without problem for the last few months. Then who knows... I'm at a complete loss.
Just to update the symptoms:
From cold start it seems to drive fine... within' about a block of driving it begins to surge pretty bad. I can barely get it up to about 20-30 miles per hour and when I do it's with a lot of light on the pedal action. The car seems to surge a little more if I have my foot even slightly on the clutch and smooths out just a hair when I fully release the clutch, but not really much at all. The car seems to surge very very badly and the sound is rougher than it normally would be. Still no CEL to let me know what the problem is.
Any suggestions or thoughts from you folks who know these engines and cars very well would be most helpful as I am out of ideas of what to do/try.
I suppose the next step will be to convert the air intake back to the original air box setup instead of the short ram I've been using without problem for the last few months. Then who knows... I'm at a complete loss.
Just to update the symptoms:
From cold start it seems to drive fine... within' about a block of driving it begins to surge pretty bad. I can barely get it up to about 20-30 miles per hour and when I do it's with a lot of light on the pedal action. The car seems to surge a little more if I have my foot even slightly on the clutch and smooths out just a hair when I fully release the clutch, but not really much at all. The car seems to surge very very badly and the sound is rougher than it normally would be. Still no CEL to let me know what the problem is.
Any suggestions or thoughts from you folks who know these engines and cars very well would be most helpful as I am out of ideas of what to do/try.
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daewoomofo
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Pedal on the clutch feels fine. Shifts okay.
Only other thing I can think of clutch wise that could be an issue around the clutch is that if I have it pressed in and hold it when I start it up... it will idle a little high, but if I drop it into neutral and let the clutch out, it drops the idle down a little. Neutral isn't exactly neutral, is what I'm getting at.
Generally feels like I'm not getting much power to the wheels? You don't think maybe I have low transmission fluid or something do you?
I had considered that as a possibility since it runs fine for the first few seconds of driving from a cold start and quickly degenerates into "can barely get going" and sluggish/hesitation problems.
Only other thing I can think of clutch wise that could be an issue around the clutch is that if I have it pressed in and hold it when I start it up... it will idle a little high, but if I drop it into neutral and let the clutch out, it drops the idle down a little. Neutral isn't exactly neutral, is what I'm getting at.
Generally feels like I'm not getting much power to the wheels? You don't think maybe I have low transmission fluid or something do you?
I had considered that as a possibility since it runs fine for the first few seconds of driving from a cold start and quickly degenerates into "can barely get going" and sluggish/hesitation problems.
No it wouldnt be your tranny fluid. Wouldnt hurt to check it however, but it wouldnt cause the problems your having I don't think.
It's odd that it only does it when it warms up. My friend's car does the opposite atm, it runs sluggish when he starts it [if it start sometimes] then kinda goes away.
When the Air flow meter is plugged in, it idles fine but doesnt rev, it splutters and coughs stuff up the intake, when it's unplugged, it idles very lumpy, sometimes stalls itself, but it revs freely.
I dunno what your problem could be anymore, tbh.. Sorry
[EDIT]: Just thought about something there, when his Air flow meters unplugged it over fuels and kinda has the same affect yours has? the roughness and spluttering. Could your car be over fueling? Dunno if that explains why it does it after a while of running, as the pressure usually builds up pretty quickly... just a thought
It's odd that it only does it when it warms up. My friend's car does the opposite atm, it runs sluggish when he starts it [if it start sometimes] then kinda goes away.
When the Air flow meter is plugged in, it idles fine but doesnt rev, it splutters and coughs stuff up the intake, when it's unplugged, it idles very lumpy, sometimes stalls itself, but it revs freely.
I dunno what your problem could be anymore, tbh.. Sorry
[EDIT]: Just thought about something there, when his Air flow meters unplugged it over fuels and kinda has the same affect yours has? the roughness and spluttering. Could your car be over fueling? Dunno if that explains why it does it after a while of running, as the pressure usually builds up pretty quickly... just a thought
SAZ
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Fixed!
The Catalytic converter was all kinds of full of crap. They replaced it with a new CAT and removed the resonator for me as well in the process (just running pipe where the resonator was). More power than I was used to before and it's running like a champ now.
Just thought I would toss out the update...
Also... I know that CAT problems are usually symptomatic of other problems... so what do you suppose would be the issue with the engine that caused the CAT to fail?
The Catalytic converter was all kinds of full of crap. They replaced it with a new CAT and removed the resonator for me as well in the process (just running pipe where the resonator was). More power than I was used to before and it's running like a champ now.
Just thought I would toss out the update...
Also... I know that CAT problems are usually symptomatic of other problems... so what do you suppose would be the issue with the engine that caused the CAT to fail?
Yeah... it's almost 8 years old at this point (amazing how much time flies).
Here's what I've been able to come up with:
Prolonged overheating or short term severe overheating are the leading causes of catalytic converter plugging. The underlying cause here is often fouled or misfiring spark plugs, or a burned exhaust valve that leaks compression and allows unburned fuel to pass through the combustion chamber into the exhaust.
Also this:
If the outlet temperature is a lot hotter (more than 500 degrees F) than the inlet temperature, it indicates unburned fuel in the exhaust. The most likely cause would be ignition misfire (fouled spark plug, shorted or open plug wire, cracked distributor cap, arcing rotor or weak coil), or a compression leak (burned exhaust valve). But other causes may include lean misfire (check for vacuum leaks, leaky EGR valve, low fuel pressure or dirty injectors). A single misfiring spark plug can cause an increase in HC emissions of 2,500 or more parts per million, which can push the converter's operating temperature well above its normal range.
...
But in any case. I'm just glad it's fixed now too.
I kinda like the new sound it makes with no exhaust resonator (or air intake resonator for that matter either).
Here's what I've been able to come up with:
Prolonged overheating or short term severe overheating are the leading causes of catalytic converter plugging. The underlying cause here is often fouled or misfiring spark plugs, or a burned exhaust valve that leaks compression and allows unburned fuel to pass through the combustion chamber into the exhaust.
Also this:
If the outlet temperature is a lot hotter (more than 500 degrees F) than the inlet temperature, it indicates unburned fuel in the exhaust. The most likely cause would be ignition misfire (fouled spark plug, shorted or open plug wire, cracked distributor cap, arcing rotor or weak coil), or a compression leak (burned exhaust valve). But other causes may include lean misfire (check for vacuum leaks, leaky EGR valve, low fuel pressure or dirty injectors). A single misfiring spark plug can cause an increase in HC emissions of 2,500 or more parts per million, which can push the converter's operating temperature well above its normal range.
...
But in any case. I'm just glad it's fixed now too.
I kinda like the new sound it makes with no exhaust resonator (or air intake resonator for that matter either).