kaj

iTrader: (60)

car ran fine last night.

i pulled out the MAF/air filter. reinstalled the MAF/air filter.

started car this morning and it sounded like it was running on three cylinders. like a heavily-cammed muscle car. the a/f was moving around from 14.7-17.5.

after about 30mins of driving, i got a P0011. i took the sensor off and cleaned it. the trigger is tight and doesn't move. the sensor looked fine. i reinstalled the sensor and made sure the plug was attached correctly. i then cleared the code via EvoScan.

car seemed okay but then started idling funny again. also, while cruising on the freeway, the RPM and MPH would stay the same, but it felt like the car was losing power. weird. i was also logging quite a bit of knock as i would transition from vacuum to boost. car was cruising at about 10" of vacuum. i thought i remembered it normally being around 15 or so?

when i got home i had a CEL with codes P0113 and P2228. i cleared them. it came back. i haven't touched any of the sensors. no idea why they would be wrong.

i start the car and it starts fine, RPM goes up a bit, as normal, but when it settled, the choppy, lopey idle returns. it then kicks the RPM up a bit, which smooths out the idle.. then comes back down. almost like a vacuum leak?

when i turn on the A/C and the RPMs raise, it seems to run a bit better.

i'm stumped. i even did a compression check on a mostly-warm engine:
all cylinders jumped right up to 90 then gradually increased to 150/145/140/132

i've swapped MAF sensors.

anyone have any ideas??

jvb6806

iTrader: (3)

if you have swapped the MAF out with a known good one you need to check voltage to the plug and resistance of the sensor.

this is the diagnostics for the intake air temp sensor (P0113 DTC)

voltage coming to the intake air temp sensor should be 4.5-4.9v on pin 6 (2nd pin in from the left with the tab of the connector facing upward)


(plug pinout in wiring harness)

........XXX.......
7-6-5-4-3-2-1


and the resistance inside the MAF between pins 5 & 6 should be...

13 - 17 kOhms [at -20 degree C (-4 degree F)]
5.3 - 6.7 kOhms [at 0 degree C (32 degrees F)]
2.3 - 3.0 kOhms [at 20 degrees C (68 degrees F)]
1.0 - 1.5 kOhms [at 40 degrees C (104 degrees F)]
0.56 - 0.76 kOhm [at 60 degrees C (140 degrees F)]
0.30 - 0.42 kOhm [at 80 degrees C (176 degrees F)]

(pinout of MAF plug)

........XXX........
1-2-3-4-5-6-7

if all that is good you need to pull the ECU and check for voltage and continuity there. there is a possibily that that ECU is dead but my guess would be a wiring issue.

hope that helps.

kaj

iTrader: (60)

hell, yes it helps. i dug through the service manual all i could to find this info.. but my eyes started burning so i had to take a break. LOL

i see the IAT is in the MAF. the IAT had some oil on it, so i wiped it off with a cloth. i was careful to not touch the smaller element. that's when the car started running like ***. so i sprayed it all down with MAF cleaner. didn't help.
swapped another MAF. no dice.

i'll get to it with my volt meter in the morning. thank you very much. i'll post back the results.

noob question: to test resistance inside the MAF, i just have to test the voltage at room temp? so i should expect 2.3-3.0kOhms? or is there a way to fool it by changing a setting in EcuFlash or something?

jvb6806

iTrader: (3)

going through the diagnostic check list it said to check for .3-1.0 kOhm. that didn't seem right, that list is at operating temps i found on another page.

i have the full break downs for testing the ECU and for testing the barometric sensor as well. PM me your email and i can shoot them to you in a PDF.

it is all step by step.

kaj

iTrader: (60)

I didn't starttesting yet. No worries. PMed and thank you very much.

kaj

iTrader: (60)

I just swapped injectors. I used the FIC rubber kit. One had a slight tear in it. Maybe it ripped the rest of the way or is otherwise not sealing.
I know a vacuum leak can make the car run this way, but would it throw these codes?

kaj

iTrader: (60)

I just swapped injectors. I used the FIC rubber kit. One had a slight tear in it. Maybe it ripped the rest of the way or is otherwise not sealing.
I know a vacuum leak can make the car run this way, but would it throw these codes?

kaj

iTrader: (60)

MaF seems to test fine though AllData says I sould have 0.3-1kOhm between pins 5 & 6 on the sensor but all 3 MAFs I have read 1.4kOhms and 2 are confirmed to be in working order. I assume mine must be okay.
Harness shows correct voltage coming from ECU.


Cleared codes. Started car and both DTCs came back immediately.

Tonight I'm swapping ECUs. After that I park the car indefinitely.

Anyone?

jvb6806

iTrader: (3)

sorry man, hope the ECU swap fixes it. other than that i got nothin.

have you considered demon possession? i think the transmission in my 1G had that

Evoryder

iTrader: (55)

p0113 and cam related code = 99% of time results in bad crank position sensor on it's way out.

Test that before spending anymore more money.

kaj

iTrader: (60)

I'm actually leaning towards possesed.

I guess I can swap crank angle sensors. Just not looking forward to pulling front of engine apart. Again. I don't even know how to test the sensor. Meh.

Evoryder

iTrader: (55)

^ no manual?

kaj

iTrader: (60)

i have the Mitsu shop manual, but can't find anything in there that mentions how to test the sensor.


so, last night i adjusted my tune a bit. since my vacuum was so low and the car idles like a big-cammed v-8 i tried upping the idle to 900rpm. low and behold, the car idles normally and has no CELs. i recently installed Tomei 264s and didn't really think vacuum would be affected. plus, the car ran FINE the day before.
maybe my RPM adjustment is just masking a real issue elsewhere?

with the p0113 and p2228, can that only mean a faulty sensor or can a low-vacuum/bad idle situation cause a problem and make the MAF THINK there is a problem when there is not?

jvb6806

iTrader: (3)

to test the crank angle sensor you will need an oscilloscope and check the wave form. wave should be uniform and come down as the engine goes to DTC on each cylinder. if you don't have the pigtail you have to use pin 89 at the ECM.

what was your idle at before? my factory idle is right around 850-900 rpm.

glad the issue apparently worked its way out.

kaj

iTrader: (60)

idle was at 800 (or slightly below, as EcuFlash doesn't allow exactly 800). i bumped it up to 900. it's not much but makes ALL the difference in the world. i also had to bump up the idle while A/C is on.

so far, so good. gonna use up a tank of gas today. i'll post the results.

as for the oscilloscope, i don't have one. but know someone that does. and yes: i'll also have to use the pin.
do you know, off hand, which plug 89 is on? or.. i can stop being lazy and look it up in my service manual. LOL