Please Help!, pro's needed! Options

[j0ch0a94ST]

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

[ST205WRC]

has there been any other work done. did it just randomly one day decide to not have any power? was there any major maintenance done on it around the time that it started actin up? i.e. timing belt, water pump, oil pump..... blah blah. does the exhaust tone sound normal? like does it sound like a subaru? (it may sound funny but i had a buddy throw a rocker on an sr20 on the intake side and it sounded exactly like a boxer engine, this resulted in a bent valve by the way). does it pass a compression test?

[presure2]

timing.

[Neon90424]

I read fuel filter but not fuel pump

[6G96GT]

timing.

You should listen to this guy.

[j0ch0a94ST]

Sorry guys. Little back story. Took the car to the carwash. Pressurewashed bay (grocery bag over dizzy etc. Left the carwash and had subbie sounding celica so I pulled over and one of the connections on the dizzy from the spark plug wires had gotten knocked loose. Ran fine home. Let car sitt for a couple of days and went to go somewhere and boom subbie celica(firing was off). Checked the spark plug wires resistance and one was bad so I got new wires. Checked the dizzy, injectors, changed plugs and wires but have had problems ever since. I don't think the fuel pump is bad. Have not done compression test but that is soon. Car us pulling vacuum and no vacuum lines are missing. Thanks. Hope this helps. Its been underpowered for months. With the distributor advanced all the way it fires normally but retarding the dizzy will make it subbie celi once again.

[j0ch0a94ST]

Sorry guys. Little back story. Took the car to the carwash. Pressurewashed bay (grocery bag over dizzy etc. Left the carwash and had subbie sounding celica so I pulled over and one of the connections on the dizzy from the spark plug wires had gotten knocked loose. Ran fine home. Let car sitt for a couple of days and went to go somewhere and boom subbie celica(firing was off). Checked the spark plug wires resistance and one was bad so I got new wires. Checked the dizzy, injectors, changed plugs and wires but have had problems ever since. I don't think the fuel pump is bad. Have not done compression test but that is soon. Car us pulling vacuum and no vacuum lines are missing. Thanks. Hope this helps. Its been underpowered for months. With the distributor advanced all the way it fires normally but retarding the dizzy will make it subbie celi once again.

[Neon90424]

my 7GC did went Subie on me! was the coil on plugs...maybe check the module thing that feeds to the dizzy?

[Bitter]

Failing cam position sensor? Bad ECM? Bad knock sensor? Bad MAP sensor? Faulty distributor?

[stephen_lee]

you should replace the cap n rotor.

also you couldve jumped a tooth on ur timing belt..

[j0ch0a94ST]

sorry guys I meant to put that I've already replaced cap and rotor

jumping a tooth may be a possibility b/c I haven't had the timing cover off to check

[SwissFerdi]

Just to get a safe answer, pull the cover off...

[stephen_lee]

turn engine till notch on crank pulley lines up wit the 0* mark on the timin cover. pull valve cover off. hole in timing gear should match with notch in camshaft cap behind it

[Rav4Race]

may i know what kind of power loss is it? is turbo boosting correctly? how many psi? or is it an hesitation power loss?

[Neon90424]

lol no turbo spool at all!

[j0ch0a94ST]

may i know what kind of power loss is it? is turbo boosting correctly? how many psi? or is it an hesitation power loss?

Yeah man sorry no turbo here. Wish we had more gt4's in the states.

will be checking timing by this weekend

[j0ch0a94ST]

Here's a 0-55ish video we took to show how slow it is now. We're pretty sure it slipped timing. So we'll take off the valve cover tomorrow to check like you guys suggested.

http://youtu.be/WpSvCfQJCJ0

[d3ath2009]

Here's a 0-55ish video we took to show how slow it is now. We're pretty sure it slipped timing. So we'll take off the valve cover tomorrow to check like you guys suggested.

http://youtu.be/WpSvCfQJCJ0

That vid actual doesnt help your case any. That performance is about right for the 7a. Idk what kind of performance you were getting before, but anything more than what was shown in the video would not be for a stock 7a.

[trdproven]

timing belt off? affecting your ignition timing.

check anything with your ignition as well.

[Bitter]

that does sound a bit sluggish and I used to own a 7A with an auto trans.

[j0ch0a94ST]

That vid actual doesnt help your case any. That performance is about right for the 7a. Idk what kind of performance you were getting before, but anything more than what was shown in the video would not be for a stock 7a.

How is that anything close to stock? That was like 17 seconds to 55. Thats not even CLOSE to stock performance for the 7A.

[SwissFerdi]

^ Truth. 7A is "slow," but that not slow. My auto accelerates faster than this.

[stephen_lee]

turn engine till notch on crank pulley lines up wit the 0* mark on the timin cover. pull valve cover off. hole in timing gear should match with notch in camshaft cap behind it

try this

[j0ch0a94ST]

turn engine till notch on crank pulley lines up wit the 0* mark on the timin cover. pull valve cover off. hole in timing gear should match with notch in camshaft cap behind it

So we did this today and the timing is correct, tdc is correct etc. Also we did a compression check and results were as follows:

Compression on #1 Cylinder = 200
Compression on #2 Cylinder = 190
Compression on #3 Cylinder = 200
Compression on #4 Cylinder = 190

To add when I was underneath the car turning the motor over by hand, I could hear what appeared to be pressure or air escaping. I'm not sure if this is normal but it sounded like it was coming from inside the cylinders so that's why we did the compression check. I'm probably going to buy a vacuum gauge this weekend and check that as well. Any other ideas guys? It is much appreciated

[Neon90424]

Well an engine is basically a giant airpump if it isnt exploding with fuel...how was the "air escaping" sound like? air going out of cracks?

[stephen_lee]

air will leak pass the rings when u spin the motor slowly. you hear this

[j0ch0a94ST]

air will leak pass the rings when u spin the motor slowly. you hear this

Thanks man it is appreciated. I wasn't sure if that was normal. However you have any ideas on what else may be causing the powerloss? Thanks

[ricochet1490]

did you get everything figured out?

[j0ch0a94ST]

did you get everything figured out?

Throwing the vacuum gauge on it sometime this week

[rave2n]

This may sound stupid, but is your e-brake stuck in position?

Cause if compression is good, timing is good...i'm confused =P

[Smaay]

yes you will hear that air sound, thats totally normal. Your compression numbers are perfect too. its possible that your fuel pump is failing and you are running lean or your injectors might be really clogged.

[j0ch0a94ST]

This may sound stupid, but is your e-brake stuck in position?

Cause if compression is good, timing is good...i'm confused =P

Nah man the e-brake releases properly, I tested it on a hill and everything, cause i was thinking it may be dragging.

yes you will hear that air sound, thats totally normal. Your compression numbers are perfect too. its possible that your fuel pump is failing and you are running lean or your injectors might be really clogged.

The weird thing is under factory distributor positioning you can smell that its running rich -_- if the vacuum test yields no indications that I'm just lost

I'll cherish the day that I get this diagnosed. You guys have all been an amazing help.

[ricochet1490]

fuel pressure regulator? I don't know... what else would cause it to run rich like that? If it was something that confused the ECU, it would have relearned everything by now I would imagine. I mean it changes A/F all the time with varying conditions. Because your problem developed after a pressure washing I would stay focused on electronics and locations of seals.

[Needles]

did you check your air filter^? hahaha

This post has been edited by Needles: Oct 27, 2011 - 11:23 AM

[stephen_lee]

Check the lines to the MAP sensor.

Might also try to O2 sensor.. but if its lacking power even at WOT I wouldnt think the O2 is at fault as the ecu ignores pretty much every sensor at WOT other than RPM, knock sensor(?!?!) and MAP.

[ricochet1490]

^x2 = if water got in an around that MAP and somehow threw it off but not enough to throw a code, the ecu could be dumping in the fuel. For instance if it's reporting a -20F temp or miscalculating the flow of air or something that would make the ecu dump the fuel to it..... work an inspection anyway. May not even be "water" but maybe something like water deposits, calcium etc.

[xrav22]

^x2 = if water got in an around that MAP and somehow threw it off but not enough to throw a code, the ecu could be dumping in the fuel. For instance if it's reporting a -20F temp or miscalculating the flow of air or something that would make the ecu dump the fuel to it..... work an inspection anyway. May not even be "water" but maybe something like water deposits, calcium etc.

I would never spray an engine with water because the water is going into your harnesses and creating rust/coorrosion. The lube or silicone from the factory is long gone.
I would say you have a few corroded connectors. It happened after spraying car with water so I don't think your timing jumped. If you sprayed your injectors ect. with the water it could be very likely you caused the connectors to corrode mabey others as well. I would clean them all. Look at them and use a small wire(copper)brush
on any iffy ones and set the timing back to normal. Good Luck.

[j0ch0a94ST]

So we tested the vacuum and it was at 21hg, I unplugged the MAP sensor and the car ran worse so the sensor is not necessarily bad but may be misreading. I'm going to a junkyard tomorrow to pick up another MAP sensor and possibly other parts. We are planning on taking off the EGR tomorrow and seeing if its clogged. Also going to check TPS sensor but I am running out of ideas. To recap it is still running RICH(you can smell it) when the distributor is at factory positioning. This has been a year long process so I'm in no hurry. The car still goes down the road, I'd just like for it to be running as good as it possibly can. Thanks for all the help

[j0ch0a94ST]

UPDATE: We replaced the MAP sensor as well as the TPS (throttle position sensor) today with no luck. Car still runs the same. I got a set of 3sfe injectors from a junkyard and am going to swap them to see if any of the injectors are bad. Also going to clean out EGR. After that I'm running out of ideas

[j0ch0a94ST]

EGR and injectors checked out

[j0ch0a94ST]

EGR and injectors checked out

Thinking I'm going to try another distributor and change the timing belt next

[kurt95gt]

might sound stupid but when my battery was going bad on my 91 gt she ran rough an felt under powered
so might want to test that an your alt
oh an check the fuses to I had a one that made her bog down little to can't remember what fuse
hope that helps

[j0ch0a94ST]

might sound stupid but when my battery was going bad on my 91 gt she ran rough an felt under powered
so might want to test that an your alt
oh an check the fuses to I had a one that made her bog down little to can't remember what fuse
hope that helps

Thanks will do. Anything is a possibility at this point