Can't figure out the problem (1 Viewer)

[mudgarden]

I just bought a stock '93 80 two months ago, and I'm starting to build it. It's been running great, passed smog with no problems, and I've already took it off road with no incidents. I've replaced the air filter/plugs/misc. tune-up items as soon as I got it and it was working great afterwards.

Quite suddenly I'm having a problem and I'm hoping this isn't an expensive cat replacement job: It is idling rough when in gear, but does fine in neutral. Once the car is warm, it has no issues, besides an infrequent quick dip in the rpms while idling in gear at a light (is this a symptom?). When the car is cold and I put it into drive, it's rough, barely goes at all, once it gets up to about 30mph it is ok. The check engine light has gone on as well.

This has all happened since the last time this has been off road, on a rainy day in the mud. It was a little wet under the hood when I was finished (of course its all been dried out since), but I've had less hardy vehicles that wouldn't hiccup when some moisture was introduced - so I'm assuming (hoping) that's not the issue.

I've run this by a few people and they suggest changing out the cats and o2 sensors, but I've found out that is not an affordable first try option. I've crawled under and banged on the cats and have no rattle.

Is this something typical/easy to fix on a cruiser or am I destined to take it into a pro?

Thanks in advance for helping a noob

 

[woody]

The check engine light has gone on as well.

that's your answer...stop by your local AutoZone or buy your own $30-50 code reader and find out what code the computer is tossing.

without that, it will be LOTS of expensive guesses...

 

[Brentbba]

Stock '93 you don't need a code reader - it's OBD 1. Just stick a paper clip between jumpers E1 and TE1 IIRC, turn the key to on w/o starting the engine and count the number of blinks on the check engine light. There will be one long pause as these are two digit codes. Post back the number and one of us can look it up in an FSM for you. It's likely that you just got some water/moisture in the air filter and it will take a week or so to completely dry out. Been there, done that myself.

The code reader is on the firewall on the PS btw.

 

[dfmorse]

While ur at it, check the corrugated air hose from the air cleaner. It could have a small crack in it, which will cause some of ur problems.

...

 

[mudgarden]

Thanks, I'll check the code when I'm back home and get back on the board with the info.

Changed out the corrugated air hose which was cracked about a month ago, but I'lll see if I damaged it again in the meantime.