90L Running Strange After a Rain

[PaulLehr]

My daily driver is my rusty but trusty 90L 5 speed. Not too long ago it developed a problem. After it rains outside it will run strange. it will start and idle just fine. When I drive and get it around 3k RPM it will buck and feel like its missing or something. Sometimes its worse than others. If I leave it in 3rd or 4th gear and floor the gas it will feel like it died until it coasts for a bit then begins to make power again. Ive checked the cap and its always dry inside. Ive put new plugs and wires on it and Ive also gone through all the plugs in the ignition system to clean them up and seal them with di electric grease. Now I'm stumped. Any ideas of what to check next?

[mattswabb]

Mine do this all the time and I solve the problem by changing the cap, rotor and wires. It seems that they last a year or so.

I'd say recheckor replace everything, spray the wires with wd-40 to displace any moisture.

[studdyhalllooser]

when i washed my engine it did the same thing. water got into the throttle position sensor and bridged the 3 points in there. take the cap off your tps and check for moisture buildup next time it rains....all asuming you have a FI festiva
Jay

[packrat427]

Paul ,you know I chased that very same problem ,if you remember all my post ,I never figured it out ,one day it just quit doing it .
Right before my trip i was going to take in it to CO. I cleaned every connector,plug in,and sprayed them with WD-40,and the battery cables and the connectors in the block where the fusible links are .
And I ran alot of fuel drier thru it too ,just to eliminate the chance of water in the fuel . It has not happened since.
and it done it on a regular basis rain or not, the herky jerky,and the coasting like you shut it off ,and just when you think it is done it comes back on like nothing happened .
One last thing ,make sure you plug is pushed in tight on you fuel pump connector,on top of the plate and below it 2 of them .

[freshtiva]

Carb or FI ?

[mattswabb]

Carb or FI ?

It's a 90 so it's FI.

[PaulLehr]

Yes it is a FI car. Sorry I should have specified that in the original post. I will try a new cap and rotor. It couldn't hurt. I Just put new plug wires on it and have gone through almost every electrical connection under the hood with di electric grease to seal them up. My TPS was a thought as well since what ever the problem is seems to be caused by condensation. and not from the water directly soaking anything. It will usually go away after 10 or so miles of driving if its dry outside

[mattswabb]

Also look at your fusible links. On my newest festiva they were corroded and caused the car to idle rough. They were in bad shape so I changed the entire fuse link box and it smoothed out.

[miami man]

i just fixed the same problem on my 93 it was running rough after it rained and all it was a bad distributor cap. it looked good under it but replaced it anyway and i am glad i did. it was a badly corroded in the terminal that the coil wire went into..it was all green

[PaulLehr]

Last night I changed the cap and rotor. But still had the same problem this morning after a rain last night. Today after work I will check out the TPS. Should I just spray it down with WD 40 or is there something better I can do for it?

[studdyhalllooser]

i wouldnt spray anything on it. it would only have the same effect as water bridging them out. dry the points good, put the cap back on and tape it so water cant directly go inside the cap...if it continues than its not your tps. good luck
jay

edit: make sure you put it back on in the correct place or it will do the same as well.

[miami man]

before i fixed mine i was thinking of taking a hair dryer to it to see if it was a condensation on wires problem or moisture somewhere else.

[PaulLehr]

The problem ended up being my TPS after I sprayed it with some WD 40 I haven't had a a problem