engine stumbles on acceleration, idles rough, wtf

[83 supra man]

I replaced the spark plugs, it looked like one was black, one was oil soaked and the other four were fine. So new plugs, I drove it to work, it was doing fine until I floored it and it started stumbling, i then let off the gas and it went back to normal. Then the check engine light came on. (This has happened before. Whenever I floor it, the light will stay on until i turn the car off and turn it on again.) I drove the rest of the way to work taking it easy. I got back in my car after work and it was doing fine, usual rough idle, feels like theres a miss, but seems to have gotten slightly better after the spark plug change. I come to a four way stop and floor it around the corner, took it to maybe 6k rpms, car seemed fine. I pulled into blockbuster and when I came back out and turned the car on it started up but then died. I started it again and it died, so third start and it stayed on, but it was idling between 400 and 600 rpms and it sounded as tho it was running on one cylinder. you could here silence and then a exhaust, then silence and exhaust. I drove it home and it seemed like there was a huge lack of power. When ever I would put the clutch in it would almost die but not quite.

Turned it on this morning and its idling fine, still has a miss, but seems to run fine. I've been told it could be a plugged fuel filter or fuseable link? the car sat for 3 years and has 300,000 miles on it and i just bought it and haven't changed the fuel filter yet. Any help would be appreciated. If I could just fix the miss and hesitation and stumbling the car would be great.

[tfphoenix]

Fuel filter would be a great starting point. Also, you might as well do the cap, rotor, wires and air filter just to rule them out and then you have shiny new stuff. Run a can of Seafoam through with a full tank of gas too. If you still have a problem then, then you have some real troubleshooting to do and more people will have better advice. I doubt it would involve a fusible link. Good luck!!!

[83 supra man]

thanks, the more people tell me stuff that agrees with my ideas the better I feel about being able to solve this lol, I'm mechanically inclined but not electronically. I know the air filter is dirty as it has mouse poop on it from sitting but the wire appear to be newer but 3 years hurts electronics no matter what so i'll start with the fuel pump and then do the rest. also i ran a can of lucas fuel injector cleaner so hopefully that wont hurt anything

[memories83]

A car sitting for 3yrs could have significant rust particles in the tank which will get caught in the Fuel inlet screen on the fuel pump and in the Fuel Filter. Both of which significantly reduce the fuel pressure and is very noticable under load. I am assuming that you drained the 3yr old Gas? If so, it was likely rust colored.

Ditto on phoenix's idea of replacing the plugs, cap, wires, etc...

[83 supra man]

there was only a quarter of a tank left in there so i didn't bother draining it, it ran bad but then got better slightly after i filled the tank and drove a little on it. but now its worse than before. I'm gonna start with the fuel filter and see what happens

[supergregotti]

Read through this thread http://www.celicasupra.com/forums/showthread.php?58203-NEED-HELP....seriously.....PLEASE&highlight=cone

[memories83]

Go through the thread that Greg listed above. It is great resource for this problem.

With only a 1/4 tank of gas that left 3/4 of the tank exposed to moisture, so expect some rust in the tank. May not be too bad but you should drain the tank using the handy drain plug. You should also change / clean the filters as has already been discussed. If there is rust, and it's not to bad, then you may have to repeatedly drain the tank and clean the inlet screens before finally getting enough out so that it is dependable. I had to drain mine three 3 times and run at least 6-7 tanks before the inlet screen was finally not clogged. A seperate inline filter may also help save the OEM fuel filter, which is the worse piece of engineering that you can imagine. you'll know what I mean soon enough. :)

[83 supra man]

Yea I saw where the filter is located, awesome lol. is the drain plug the big plug in the middle of the bottom of the tank, looking at it from the outside?

[memories83]

Yes. It has a square hole for a socket extension. 3/8, I believe.

[83 supra man]

sweet, thanks for all the help, I appreciate it.

[83 supra man]

sooo, turns out my number six cylinder wasn't firing, cause... bad spark plug wire, caused the smoke to go away too lol go figure.
also I wrapped some tin foil around my fuses and got my turn signal lights to stay working and my dash lights to stay on (digital dash)
i think its coming together now :) hauls ass thats for sure, i dig the canadian model '85 p-type with the digital dash and 5-speed.
some punk in a 2000 vw gti VR6 tried to outrun me, poor guy almost couldn't keep up with my 300,000 mile motor lol

[memories83]

That's good news but I hope the tinfoil on the fuse was a TEST thing. If it's shorting out then there IS a short. Not trying to be critical but you need to find and fix the short. A quick search on this forum will bring up several recorded fire events. Don't want that to happen to you and your new ride.

[83 supra man]

there aren't any shorts that i have found so far, just a lot of corroded connections. the tinfoil is to get me buy till i feel confident enough to install a new fuse block with good connections

[sowsley]

That's good news but I hope the tinfoil on the fuse was a TEST thing. If it's shorting out then there IS a short. Not trying to be critical but you need to find and fix the short. A quick search on this forum will bring up several recorded fire events. Don't want that to happen to you and your new ride.

A couple of weeks me and a buddy put tinfoil around a Model A Ford Generator fuse just to drive it 1/4 mile. The engine would have caught on fire had there been oil nearby - turned out there was a major short in the steering column. The fuse terminals melted off the terminal block. It got that hot with a 6 volt battery.

http://i180.photobucket.com/albums/x305/sowsley/ModelAFuseMeltdownMedium.jpg