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project 1mz celica - 6G Celicas Forums

Topic #82235 1159 posts Started by kurt95gt
At idle my maf is 7.1 an my timing is 15.5 at 880rpm

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
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QUOTE (Smaay @ May 3, 2012 - 10:01 AM) *
>O2 sensor wont throw a flashing CEL. cam timing might be out, have you done a compression test?

O2 sensor will throw a flashing CEL, not because the O2 code but because the AFR gets so jacked up it causes a severe misfire across an entire bank of cylinders.
Just because the O2 sensor is bad doesnt mean he will get an O2 sensor code unless its shorted or open. He can try to graph the zero crossings on the with the scanner but Im gonna guess his fuel trim on that side is gonna be pretty far off.
New little fun fun fact i can disconnect the sparkplugs to 1,3,5 she still sounds an revs the same!!!

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
coil to rear bank dead?

"The buy my stuff, for help make great finish project of celica fund!"
No the coils seem to be firing but i think the plug wires arent getting spark to the bank

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
Check each individual plug for spark to ensure that you're getting spark. I would bet that the rich smell that you're smelling is fuel blowing straight through the exhaust. Nonetheless, after checking for spark remove those three plugs and see if fuel blows out of each cylinder when you crank it over. Or you might get lucky and there will be fuel on each plug when you take them out. If the plugs each fire perfectly and you can confirm fuel in each cylinder, then that leaves only timing.

Edit: I forgot to say, pull the fuel pump relay before checking for spark. Definitely don't want fuel blowing out of the cylinder with a spark plug firing right there.

This post has been edited by richee3: May 3, 2012 - 10:42 AM

"Employ your time in improving yourself by other men's writings, so that you shall gain easily what others labored hard for." -Socrates. Even Socrates told us touse the search button!2006 Aston Martin V8 Vantage.1998 Celica GT-BEAMSSwapped.2022 4Runner TRD Off Road Prenium.2021 GMC Sierra AT4.
Its all sounds alot easyer than it is since the 3in question have a intake hanging over them lol

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
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QUOTE (kurt95gt @ May 3, 2012 - 10:41 AM) *
>Its all sounds alot easyer than it is since the 3in question have a intake hanging over them lol

Didnt you say you had somehow rigged the O2 sensor in an earlier post? Was it the bank one sensor?
Yes an yes edy
I changed out the plug wires an checked spark an im getting spark to all 6 cyl
Im about to chabg out the e3 plugs for the stock coppers an put in the new fuel filter

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
Checked plug on cyl1 an it was loose so im going to try an tighten them up tonight after work an change my fuel filter an see what happens

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
Getting closer, slowly but surely. redface.gif

2001 Miata LS 5-speed
The pre-cat O2 sensor control fuel to air ratio adjustments for the cylinder bank its installed on. An exhaust leak, an improperly installed O2 sensor(I/E sticking to far into or to far out of the exhaust pipe), the wrong O2 sensor for the engine or more specifically the ECU, or faulty wiring will cause inaccurate readings of the air to fuel ratio.
The computer would recognize a shorted/open circuit or improper response time from the O2 sensor and display a fault code. But sometimes, the ECU does not detect the malfunction of the O2 sensor and attempts to adjust the fuel trim to match the inaccurate readings. This causes a misfire condition of the cylinder bank with the incorrect functioning O2 sensor, either lean or rich.

The chances of all three plugs or wires being defective of only one cylinder bank are slim. By my calculations there is only a 4% probability that IF 3 plugs or wires are misfiring on a V6 THAT they are all located on the same cylinder bank. 96% of the time the misfiring plugs/wires will be spread between both banks.
Of course, unless you physically removed the plugs yourself there is an increased chance that some jackass before you only replaced the bank 2 plugs because they were to lazy to remove the intake manifold.

The chances of a coil malfuntion causing all three bank one cylinders to misfire is next to 0% because of the wasted spark system.

What was the issue you had with the O2 sensor in detail?
If he totally unplugs the 02 sensor from the wiring harness, it should default to stock trim levels. Unplugging it totally should let him know if the ecu is getting f-ed up by a bad sensor...
Ok ill unplug the bank one o2 sensor tonight
Edy-when i was installing the motor in the original o2 sensor was getting hung up on the streering rack an in the process of trying to remove it one of the wires got frayed pretty bad an didnt look fixable or useable so i replaced it with a bank 2 sensor from the junkyard since it was easiest to get to.

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
Maybe it is the O2 sensor. Wouldn't think which bank would matter, upstream O2 sensor should be an upstream O2 sensor. Possibly the one you got was bad to begin with.

2001 Miata LS 5-speed
Maybe but might have to wait till i get my next check to find out for sure
Im running alittle low on that leafy green paper stuff
Ok?

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
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QUOTE (ricochet1490 @ May 3, 2012 - 1:43 PM) *
>If he totally unplugs the 02 sensor from the wiring harness, it should default to stock trim levels. Unplugging it totally should let him know if the ecu is getting f-ed up by a bad sensor...

Correct, or reading the fuel trim setting. The long term should be no more than 5% + or -
So far long an short term have both read 0%

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
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QUOTE (kurt95gt @ May 3, 2012 - 1:17 PM) *
>So far long an short term have both read 0%

The short term should be fluctuating. If they are both consistantly zero then your ECU is running on factory programming. When you get a chance try to graph the 02 sensor 1 on bank one and two. It should be a line that jumps up, levels off, jumps down to then levels off, jumps up , and so on
Ok ill ad that to my list
Is that more likely to happen after the motor warms up?

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QUOTE (kurt95gt @ May 3, 2012 - 1:32 PM) *
>Ok ill ad that to my list
Is that more likely to happen after the motor warms up?

Yes, the O2 sensors need to heat up to work properly. If the sensor has three or more wires then it is a heated sensor(it has a heating element inside) and it should start reading alot quicker. But your engine is going to be running rich until it warms up anyways, it has to because a cold engine doesnt vaporize the fuel as well( so it needs more gas to compensate for the fuel not being fully burned).

What you are watching for is that the short term fuel trim will oscillate between rich and lean in relation to the long term. The short term trim is going to jump higher and lower than the long term trim and the O2 sensor should follow this pattern.
Every few seconds the computer will lean the short term trim, and wait for a response from the O2 sensor. The O2 sensor will notice the lean condition, and the ECU will adjust to a rich short term trim. Of course now the O2 sensor notices the rich condition, so the ECU compensates back to a lean trim. It goes back and forth like this constantly and the Long Term fuel trim will be an average of these readings, where the ECU determines the best AFR ratio is based upon how the engine reacts to the lean/rich adjustments every few seconds. If you arent getting any fluctuation from the short term trim then the ECU is just best guessing the AFR based upon factory programming. Could be a number of things- the O2 sensors arent working, the computer is locking itself out because it thinks some kind of damage is possible due to a scary sensor reading, or the computer thinks its at WOT and is trying to enrich the engine to compensate for the expected flow of air at WOT.
Ok thanks for thr info ill try an do that tonight or in the am so i dont make the neighbors mad lol

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
Well i think i figured out my problem an i feel super stupid an im not going to post what it is till i try it an see
But hopefully ill have a post full of good news around 1am tonight

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
Well, let's hope you're right. Await good news later.

2001 Miata LS 5-speed
bet he never plugged the rear bank O2 back in...LOL

"The buy my stuff, for help make great finish project of celica fund!"
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QUOTE (mandrek @ May 3, 2012 - 8:25 PM) *
>bet he never plugged the rear bank O2 back in...LOL

How much you wanna bet on that lol laugh.gif

95 gt coupe, v6 swap weekend toy99 gt hatch beams swapped wife's94 st hatch my daily driverhttp://www.6gc.net/forums/index.php?showtopic=82235n
NO SH!T!!!!!


no for real.. if that is indeed the case! AHAHAHAHAHHAHAHAHAHAHAHAHHAHAHAHAHA!!!!! and AWESOME!!! at the same time!!! making it a simple fix.. hmm.. thought i seem to remember saying somthing about that.. b4 the FPR.... hmmmmm cwm13.gif woot.gif laugh.gif

"The buy my stuff, for help make great finish project of celica fund!"
Kurt, I'm dying right now! I know what is but I can't tell! I demand a 0-60 video tomorrow when she's ready to go hunting for some Mustangs smile.gif

"Employ your time in improving yourself by other men's writings, so that you shall gain easily what others labored hard for." -Socrates. Even Socrates told us touse the search button!2006 Aston Martin V8 Vantage.1998 Celica GT-BEAMSSwapped.2022 4Runner TRD Off Road Prenium.2021 GMC Sierra AT4.
Well, here's to hoping that's it. So ready to see this thing pound some pavement.

2001 Miata LS 5-speed
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QUOTE (mandrek @ Apr 18, 2012 - 4:24 PM) *
>though i do not have experiences with this motor, or much on diagnosing fuel delivery issues, i do have a strong basis of trouble shooting electronics.. and with the process of elimination, logic, and the info that you have already provided would suggest to me that you first look at the rear bank O2 sensor.. lean conditions on 1 bank.. and the same bank that you had a band-aide sensor put in, (and possibly still an open in the line (cut, bad/no ground, or even a high resistance contact (like a twisted splice that came lose during soldering and it now does not have a solid contact)) and a faulty sensor will not always trip a code or kick a CEL... so testing the sensor and the circuit that it is on will always be the best way of making sure that the system is doing what it needs to be doing..


hmmm yup!!!!! laugh.gif biggrin.gif laugh.gif biggrin.gif laugh.gif biggrin.gif

but no, for real.. ima stop being an a$$ and am REALLY excited to here how she's doing, and that all is well.. fingers crossed and cant wait to here the progress!!!! smile.gif

"The buy my stuff, for help make great finish project of celica fund!"