I had convinced myself it was the MAP sensor or a vacuum problem at/near the MAP (even though I couldn't get conclusive VOM readings), then I just took the $65 plunge one day at AutoZone for the upstream O2. Immediate fix for me. I'd look into the MAP sensor and vacuum lines.
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Issue with poor running
- Thread starter mdl
- Start date
98XJSport
Destiny is the rising sun
- Location
- Western Maine
Check out the coolant temp. sensor perhaps? That could cause lean/rich conditions I would think...
Timber said:
Here's the gist of backstory:
replaced exhaust manifold.
Car ran lean afterwards, CEL came on, found the code, immediately replaced upstream 02 sensor. That helped, but still the car idles high when in park and idles slightly rough when in drive. Started to go back and check some connections and realized (I'm a complete idiot for this) that I didn't tighten the connection to the air filter box properly - so I thought that this was where the vacuum leak was coming from and possibly the car will run properly now. Connected that properly, reset the pcm, took it out for a drive.
When I first start it, it's good to go and seems to run 85% properly (like it's supposed to run, can feel some shaking/vibs when I'm in the driver seat). When I put it in park after reaching a destination, it does an un-natural high idle of about 1100-1300 rpm <-- that tells me something is still wrong.
If the MAP sensor was not working properly, would it spit out a code? I've check the other vacuum line connections and they all seem to be alright. Would an over-tightened throttle body (bolts connecting it on) lead to this issue? Also, their is another connetion line that goes from the engine to the intake manifold (more towards cylinder #'s 5 n 6) that I think I might've over-tightened - (sorry I don't have the correct name, bu tthis connection is one that is scrwed in at the intake manifold and tightened there)... could that lead to this issue as well? Those are the only other things in my head that I need to check, weather so far has permitted me from doing so. Any other stuff I could check?
98XJSport said:
It can and I'll check it again cuz I've fixed that before.
nvm, did a butt load of searching.
cleaned the TB, tightened up all exhaust manifold bolts since it had been past 100 miles since installation (I think). That fixed the high idle issue, but it was still idling ever so crappy, so I sea-foamed it and it seems to be 95% great.
so I guess I answered my own question
cleaned the TB, tightened up all exhaust manifold bolts since it had been past 100 miles since installation (I think). That fixed the high idle issue, but it was still idling ever so crappy, so I sea-foamed it and it seems to be 95% great.
so I guess I answered my own question
