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j0ch0a94st
12-03-2010, 11:45 PM
Hey guys I've had an issue with my 94 ST running rough until it reaches operating temps ever since I washed the motor. I pulled the plugs and replaced the plugs. There was no water in the chambers. I have pulled the dizzy cap off and there was some moisture inside. I have dried out the cap and sanded down the terminals inside. I have currently pulled the distributor out of the car. So how do I disassemble it to look for trapped water? I've pulled out the 4 main screws but the plastic covers are blocked from coming off by the rotor button. There isn't a screw or anything holding the rotor cap on but it seems stuck. They do come off right? I just don't want to break anything. Anyone with any experience with this please help.

Thanks

85gtsblackman
12-04-2010, 07:43 AM
odd, i just drove mine around for a few hours and the one car i had that didnt start i just blew out with compressed air and it fired right up

alltracman78
12-04-2010, 04:20 PM
As long as the car has been sitting for a few hours and you didn't damage any wires/parts from the spray I doubt it's a water problem.

I wouldn't suggest you try taking the dist any further apart unless your decently mechanically inclined.
Have you tried rplcing the cap/rotor instead of just cleaning them?
Cleaning increases the gap.

GI_Johnny
12-04-2010, 08:41 PM
I have learned that if you're going to wash down the engine bay...it is best to leave the car running.

j0ch0a94st
12-05-2010, 04:37 PM
Cleaned the cap and rotor. I have ruled out the dizzy now I fear its an 02 sensor or a vaccum leak. It only runs rough(misfires) when its cold. After it runs and gets warm it runs better but has significant power loss. The wash happened about 3 weeks ago so I think any of that water has evaporated by now.

lowdowndirtyota
12-06-2010, 07:18 PM
i would just replace the cap, rotor and wires if there old anyways. can never hurt. and if you hook it all up and it doesn't work simply return them to your parts dealer if your strapped for cash. i think its best to cover the cap, battery and alternator with plastic bags when washing under the hood for future reference. but i never did it with the car running. something tells me that water and electric mixed is not good. lol. good luck and i hope this helps.

j0ch0a94st
12-07-2010, 02:43 AM
Refer me to a parts dealer that will restock plug wires please :) I went up to Advance Auto and they said they couldn't restock plug wires if I "tried-them-out" The plugwires are about 3 years old but there is no corrosion or arching that I am aware of. I'm leaning towards bad or gunked up o2 sensors @ this point. Going to remove the one up front tomorrow since its easy to get to and soak it in some brake parts cleaner and see if it helps. Do you know if the single wire ford 02 sensors are interchangeable with these? Just curious cause I am strapped for cash with x-mas coming up and what not and the ford single wire sensors are like 15 bucks. Thanks for the bag tip but I think after this experience I'll just be wiping the thing down with a rag from now on :)

lowdowndirtyota
12-08-2010, 03:57 AM
im not sure about the o2 sensors. and i dont condone returning used parts but do so at your own risk. i have life long friends that work for parts dealers that would return items for me because they know i wouldnt damage the parts and know i know what im doing. we are all strapped with the holidays, i understand. good luck and post with results please.

j0ch0a94st
12-09-2010, 06:38 AM
Thanks, will do.

j0ch0a94st
12-09-2010, 09:54 PM
So here's what I've got so far. It drives relatively normal up to ~ 3500RPM or so and then there is a major drop off in power. Accelerating feels compromised. I though I may be having issues with o2 readings so I checked the sensors today. I unplugged the sensor on the back of the motor and have no check engine light. I know that the sensor used to throw a code when it was unplugged previously. I am still unsure what's causing the power loss. Does this sound spark related to anyone? Thanks for the help.

moadyb
12-11-2010, 03:11 AM
There is a few things to consider when diagnosing a rough idle or loss of power.
1) water in the dizzy
2) hole in the firewall causing water to get to the ecu
3) remote mounted coil and igniter get blasted by water
4) vaccum leak (if there isn't a mass air flow or vafc on the intake tube it is easy to start the car and put your hand over the throttle body as to block the air flow and cause the car to stop running. If it starts to die but continues to run at a very low idle you can ussually here the vaccum leak. However if it has a MAF OR VAFC it's more difficult because they need to be connected for the car to even start and their normally mounted in a way that makes it difficult to block off for that type of test.
5) intake manifold leak (if there was something like oil grime or dirt blocking a spot where the bad part of the gasket sealed the Manifold to the Head and you washed it off then air would come in through that bad spot and cause and irratic idle and loss of power). You could take something like brake or carb cleaner or start fluid when the car is running and spray it in short burst along the mating surface of the Manifold and observe any changes in idle. If it does increase the idle or cause a change of some sort you could feel pretty certain it's leaking from there.

There is much more to consider that's just some quick checks to preform.

As far as taking apart the dizzy it's usually not neccesary as to say that even if you did dissassemble it you wouldn't do any more good than if you just checked the air gaps and ohm readings of the sensors. Blowing off the cap, rotor and internals should solve the water issue if any. Futher dizzy issues should result in a MIL code.

j0ch0a94st
12-11-2010, 07:40 AM
K guys you've given me some things to think about. I just picked up a volt meter today and am going to check all the electrical connections, spark plug wires, dizzy etc. Thanks for the help so far.

j0ch0a94st
01-15-2011, 03:22 AM
Sorry guys here's the update on my car. I tested the plug wires and I did have one that was bad and one that was questionable. So I picked up a set of NGK wires for the celi and now its back to operating fairly normal. I don't know if its just me but it still feels like the car is short on power. I bought a fuel filter @ Advance Auto today because it is due but the damn part set me back $20! I've bought a lot of different fuel filters doing tune ups on my friends cars in the past and I've never come across a $20 fuel filter, most of them run 5-7 bucks. Anyway thanks for the help guys , hopefully I'll unlock its full potential soon.

mtp_69_i
01-15-2011, 07:23 PM
Does your motor have a single coil pack? Or individual coil packs on each spark plug? I wonder if the lack of power over 3500rpm is because the coil isn't feeding enough spark through to the spark plugs. My old bitsamissing (mitsubishi) nimbus had this problem with very similar symptoms.

Could also be crappy petrol (water in the fuel tank for instance), which can be sorted out by adding methylated spirits to the petrol I think there's also some product called "Heat" in the US you could try if you think its bad gas and don't want to try metho)...

j0ch0a94st
01-22-2011, 10:00 PM
Well mine is not coil on plug it has a distributor. The timing was advanced almost all the way on the car and now it performs like it used to. However I would like for the car to operate normally under factory timing. I have a feeling that it is spark or fuel related.

manda
01-24-2011, 03:34 AM
I've never come across a $20 fuel filter

(I have a 94 ST also) I paid $18 for mine with a commercial parts discount... which I got bc I was wearing a ctech hoodie when I bought it (guess the guy assumed I work at a shop- and in all technicality I do at times, my dad owns a shop in ATL)

85gtsblackman
01-24-2011, 03:54 AM
shoulda went to rock auto

though i got a factoy yota one for 10 bucks, thank you ebay

j0ch0a94st
10-01-2011, 07:24 AM
K guys so its been months now and my celica is still down on power. I've had other people who have had 6th gen st's drive it and they say the same. Like I stated earlier in the thread my friend advanced the timing almost all the way to get the thing operating normal or at least semi-normal. However there is still a noticeable power loss and I'm having trouble diagnosing it. I'm over at my friends house and we are going to vacuum test it tomorrow as well as retard the timing back to factory to try and trace the problem. If you guys have any suggestions as to what else might cause the power loss it would be greatly appreciated.

The following have been ruled out:
spark plugs(replaced)
spark plug wires(replaced)
fuel filter(replaced)
injectors(do not contain water)
No check engine light or other idiot lights so NO code to diagnose
Distributor has no water and appears to be working fine

Thanks again guys

**EDIT BY MOD**
My buddy did not advance the timing per timing light he just advanced the distributor all the way. Oil level is good, cam timing hasn't slipped and have not tested compression yet.

temperacerguy
10-01-2011, 07:46 AM
did your cam timing slip?, are you setting the ignition timing with a timing light? Is your oil level good, what is your compression? any other symptoms (smoke or the like?)

l0ch0w
10-02-2011, 09:26 PM
+1 on jumped mechanical timing... If your motor jumped a tooth or two, it will make your car run like crap. Just go to autozone or whatever your local auto parts store is and rent a timing light. If you arent sure how to use it, chances are that the guy behind the counter will.

If that comes out ok, I would reccomend running a leakdown test rather than just a compression test. That will give you a more comprehensive diagnosis on what your problem might be. Once again, if you arent sure of how this works, then use your google/youtube-fu to see how its done.

j0ch0a94st
10-04-2011, 12:31 AM
Thanks for your input l0ch0w. I've added some of your suggestions to my checklist. This has just been a long process with it being my daily driver and only having a parking lot to work in. (hate apt living!)

cyrusk
10-11-2011, 03:47 PM
Possibly your CAT or exhaust is partially blocked,this would affect performance.

cyrusk
10-11-2011, 03:55 PM
If you've changed the fuel filter did you also check the fuel pump? Restricted/reduced flow won't help performance either.

cyrusk
10-11-2011, 04:01 PM
What condition is the air filter in?Also some cars don't like fancy spark plugs i.e. iridium or platinum, and work better on copper.