EJ25 Swap. ran fine, then...

[xbeerd]

SO the car in the last 2-3 days has started acting kinda goofy. i'll start driving, everythings fine for a few miles then, i'll hit the gas, it'll hesitate then kick in, then hesitate, kick in etc. my idle has been sitting around 2000 rpms sometimes falls to 1600, and then sometimes will sit around 5-600rpms.

 

possibly helpful information..

 

SOHC EJ25, OBDII, (both fused) power and constant wired to a switch, from an open spot in the fuse box (via spade connector, i dont like it but its been working fine for about a month now with pretty regular driving.) grounded to the body.

 

i need to do the alternator wiring that elfreddo showed me yet.

 

resistors to eliminate fuel level sensor, and fuel temp sensor (set to 75 deg F approx)

 

my TPS was/is adjusted to 10%, as thats how it was set on my buddies 04 2.5rs (checked via obdII usb data cable /laptop)

 

i dont know if maybe i kicked a wire out or something yet but everything should be secure. thats my plan tonight to check that.

 

it IS possible that my wiring to the TPS was damaged by the previous time this engine and wiring was installed by someone else. (grrr)

mainly wondering if anyones had the similar issues post swap and what they did to fix

Edited September 28, 2011 by xbeerd

[roostema4328]

you will have to drive it and look at the live readings on the sensors to see what is out of wack. I have seen a bad air/fuel sensor do things like that. or a vacuum leak. You will need to look at fuel trim data and see if the front and rear sensors are agreeing. like for example the fuel trim data shows -20% and the rear O2 is stuck at like .1 volts. that would be a dead give away that the front air/fuel sensor is bad. the reason I say that is that the rear 02 sensor shows .1 or so= lean / .8 or so = rich. If the fuel trim is at -20% that means that the front air/fuel sensor is reading rich so it is adjusting the fuel mixture lean -20%. If the rear o2 is reading .1 that means that the sensor is telling the ecu the wrong thing and actually causing it to run lean. which will make it run like crap. no power. surging. multiple misfiring etc. very common.

now if the fuel trim shows something like -20% and the rear o2 is reading rich like .9 volts at the same time. that means something else is wrong. like bad fuel pressure regulator etc. something that would cause it to run rich. ha ha

If fuel trim is +20 at idle and tapers off to almost 0 under load and accel. that is usually caused by a vacuum leak.

Not saying any of this is YOUR problem. just sending out random info ha ha

[xbeerd]

LOL, i hope that is my problem. then it should be solved after i check all that stuff.

 

thanks for the info there!

 

oh... when you refer to air/fuel are you meaning the 02 sensors.

 

oh ************, i forgot... the rear o2 sensor i expect to be running lean... since its not hooked up to the exhaust at the moment. (smack self) but its been that way for over a month now and has been fine

Edited September 28, 2011 by xbeerd

[xbeerd]

well my stupid program is a trial version so it wouldnt save the damn data long, but i took a few pics of it while it was idling. not sure if it helps or not..

 

 

 

 

any thing flag on there? or because i was just idling its not enough to tell. im lookin for a better software

 

 

now, after i took those i changed my TPS with another on i had layin around (i always grab them at the pick n pulls etc) and turned it all the way one way and the absolute throttle position was at about 5%

 

drove around a little but i dont think it was enough, true test will be in the mornin or after work tomorrow. the last 3 days it started happening right about the same spot on my way home.

[roostema4328]

the rear 02 sensor will not effect how it runs just turn on the check engine light. the front o2 sensor is the air/fuel sensor. the reason I was talking about the rear sensor is because I use it to diagnose the front one. It is rare for both sensors to be bad. the rear one hardly ever goes out. and the readings are very easy to see. rich or lean. .1volts is lean .9 is rich. it is supposed to switch between rich and lean constantly if it is switching it is good usually. you can induce a vacuum leak and watch the rear sensor to see if it sticks too .1 you can add fuel ie-propane into intake to see if it sticks to rich .9 . . Like I said before I use the rear sensor to verify the front. since the front sensor controls the air/fuel mixture pretty much directly. if the fuel trim is less than 10% either way + or - that is considered normal. but if it is more than 10% there is something wrong that is fuel related.

usually it is the front 02 sensor. you can varify that by looking at the fuel trim data and the rear o2 sensor voltage at the same time. Like if the fuel trim is at -20% that means the front 02 is measuring rich and telling the pcm to adjust the fuel ratio lean. now when that is happening the rear o2 should be showing .9 if it really is running rich. If it is stuck at .1 volts. that is lean. So obviously the front o2 should not be telling the pcm to subtract fuel if it is actually running lean so the front o2 would be bad. and actually causing the lean condition.

now say the fuel trim is at like -20% and the rear o2 is stuck at like .9 then the front and rear o2 sensors are agreeing and are both probably good. You would then have a rich condition. which could be caused by anything that would make it run rich. like map sensor, leaking fuel pressure regulator diaphragm etc.

of course none of this will help you unless you have the rear o2 installed lol

in that case by default If I had more than 10% fuel trim either way. I would just replace the front o2. you can get them cheap at napa/oreilly/carquest etc. They are very common to go bad on those and will make it run like complete crap when they do.

Edited September 29, 2011 by roostema4328

[xbeerd]

the rear 02 sensor will not effect how it runs just turn on the check engine light. the front o2 sensor is the air/fuel sensor. the reason I was talking about the rear sensor is because I use it to diagnose the front one. It is rare for both sensors to be bad. the rear one hardly ever goes out. and the readings are very easy to see. rich or lean. .1volts is lean .9 is rich. it is supposed to switch between rich and lean constantly if it is switching it is good usually. you can induce a vacuum leak and watch the rear sensor to see if it sticks too .1 you can add fuel ie-propane into intake to see if it sticks to rich .9 . . Like I said before I use the rear sensor to verify the front. since the front sensor controls the air/fuel mixture pretty much directly. if the fuel trim is less than 10% either way + or - that is considered normal. but if it is more than 10% there is something wrong that is fuel related.

usually it is the front 02 sensor. you can varify that by looking at the fuel trim data and the rear o2 sensor voltage at the same time. Like if the fuel trim is at -20% that means the front 02 is measuring rich and telling the pcm to adjust the fuel ratio lean. now when that is happening the rear o2 should be showing .9 if it really is running rich. If it is stuck at .1 volts. that is lean. So obviously the front o2 should not be telling the pcm to subtract fuel if it is actually running lean so the front o2 would be bad. and actually causing the lean condition.

now say the fuel trim is at like -20% and the rear o2 is stuck at like .9 then the front and rear o2 sensors are agreeing and are both probably good. You would then have a rich condition. which could be caused by anything that would make it run rich. like map sensor, leaking fuel pressure regulator diaphragm etc.

of course none of this will help you unless you have the rear o2 installed lol

in that case by default If I had more than 10% fuel trim either way. I would just replace the front o2. you can get them cheap at napa/oreilly/carquest etc. They are very common to go bad on those and will make it run like complete crap when they do.

 

BAH, LOL. true. ok fine (lol), i will install the rear o2 sensor which i am pretty sure is bad anyways.. i put a meter on it, and it read like 4 ohms, where i think it was supposed to be like 30 ohms or more.

 

i actually thought i found a possible vacuum leak last night in the dark but couldnt see where it was. i THOUGHT it was coming from that little part on the front of the intake manifold behind the powersteering pump, has 2 hoses (and one smaller hose i think,i forgot what part it actually was, i knew.. but forgot.)

[xbeerd]

on my way to work today, power dropped out a couple times on the highway for a second or 2 but i had to gas it up to keep it going, but that was it.

 

any chance this might be a dying fuel pump?!? my fuel pump was running fairly loud for a while (before the swap, but never seemed to fail/hinder ea82 performance

Edited September 29, 2011 by xbeerd

[roostema4328]

yes it could be a fuel pump. you would have maxed out +fuel trims in the data while the low power was happening. put a fuel pressure gauge on it and drive it to see if the fuel pressure holds.watch to see if the pressure stays up even under WOT and max load.

[xbeerd]

this is the thing where i feel the leak may be...

 

[xbeerd]

here's an update.

 

rewired my ECU 12vConstant to an actual constant, not tied in with the ECU switch, car seems to run better now. the volt meter is a little higher, not much, it still sits around 11v when i turn on the ecu/ign and then drops to about 8.5 or 9v when cranking. think that could be just a bad battery? when the cars running it looks to be about 13-14 volts in the system