91 Z34 still Sick, but now have free scan

[robertisaar]

there wasn't a size restriction a while ago.... but ZIPing files before uploading would likely help.

looking at log now, will edit quickly with initial thoughts, and if anything VERY odd pops up, i'll throw in another post.

[robertisaar]

my last reply disappeared?

oh well, try ZIP files before sending to reduce filesize, it MAY be an issue.

yeah, that O2 is not swinging at all. i assume the O2 error code eventually gets set?

the BLM/INT don't bother moving until the very end of the log, after you started putting your foot on the throttle...

i find it odd that near the beginning of the log, you idle at roughly 45kPa(normal), but when going from sample 7269 to 7836, you jump to 55kPa and pretty much never get under it. the difference in IAC steps is also ridiculous, going from 44 to 81.

i wonder if $DF uses the same alpha-N idle that $A1 does....

[portsider44]

my last reply disappeared?

oh well, try ZIP files before sending to reduce filesize, it MAY be an issue.

yeah, that O2 is not swinging at all. i assume the O2 error code eventually gets set?

Nope it has not thrown any codes at all

the BLM/INT don't bother moving until the very end of the log, after you started putting your foot on the throttle...

i find it odd that near the beginning of the log, you idle at roughly 45kPa(normal), but when going from sample 7269 to 7836, you jump to 55kPa and pretty much never get under it. the difference in IAC steps is also ridiculous, going from 44 to 81.

Could this increase have to do with blocking off MAP vaccuum port for FPR & hooking FPR to hand pump? At which point I put 23" of vac on it. Which did help to bring o2 up as I guess it leaned it out.

i wonder if $DF uses the same alpha-N idle that $A1 does....

I have not clue on that one

Also could a bad ICM cause it not to go into close loop? All I know I think it will idle for ever, but it will only last a few seconds at higher RPM. When it dies there is no stumble just dead. Fuel pressure does not drop during stall either.

At full throttle the tps only shows 4.37 is that normal?

I have pulled the IAS off & cleaned it but not change.

I sprayed carb cleaner on intake, egr, vac lines & never noticed a change in RPM.

Fuel Press Readings

Key on Not running
0" of vac =47.5
5" of vac =46.5
10" of vac=44
15" of vac=41.5
20" of vac=38

Running at idle
0" of vac =52
5" of vac =48.5
10" of vac=47
15" of vac =44
20" of vac =42

Running at idle vac from MAP to FPR is 14"

I was hoping with scan tool I could narrow things down in order to prevent throwing parts at it. However at this point I don't know what to do.

I feel that the FPR is not working properly as the readings seems high, but as you apply pressure it reduces the psi. SO while it may not be 100% could it really cause my problem. To me it would seems that it would just cause a rich condition

Could a bad IAC cause it to high great but stall at higher rpms? Is'nt it use more to control low idle?

COuld a bad alternator be the issue or would we see a drop in battey volts at stall & if so would it take a drop below 12.6?

WOuld a bad coil pack cause a high rpm stall?



Bad 02 sensore keep it from going into closed loop plus the stall

I guess at this point throwing parts might be the only way to go but where do you start first?

[robertisaar]

if i had to stake money on it, the FPR is it.

while running at idle, you have to apply between 15 and 20" just to get it to where it should be at WOT? that's a serious problem.

WOT voltage at WOT is a LITTLE low, but nothing i would consider wrong.

ICM has literally nothing to do with closed loop fueling, so i wouldn't consider it.

14" at idle COULD be believable, since running either rich or leaner than necessary WILL require more air due to less efficiency.

IAC also seems to work at least somewhat correctly.

a bad alt should be even more obvious at an idle

bad coil doesn't make much sense as it should also cause problems at idle.

the O2 MAY have been bad before this issue, but i'm guessing it probably is now anyway, since lots of fuel shortens their lives considerably.

have you checked to see if your oil was gas-filled as well?

[portsider44]

Oil does not seem to be gas filled. Car does use oil but doesnt smoke, doesn't appear to leak on ground. Not sure where it goes but it does go.

I have been looking for anything out of of order. Part of vac line that goes to front valve cover was disconnected in back. However plugging it back end did not help. Car starts, idle but once rpm go up it dies.

Also found a wire that I am not sure where it goes. Does the fuel pump relay have a test wire coming out of it? FPR relay has the heavy orange wire that goes to a red wire in harnass. Then it has 3 orange wires coming out, one green w/white stripe, one black 2 red wires. One red goes to red in harnass & the other red which is only about 4 inches long & has a gray connector with 21 PED on it. I dont see another connector that it would go to??? Is it there for testing??

Is it just me or is the o2 sensor a son of a beotch to to change. Doesnt look very accessable from underneath or from up top.

Also I noticed that the upper intake man has 2 studs on the back side that are not on correctly. Studs are on back side of UIM tabs. While not right not sure if that could be issue.

When I swapped out the radiator the fan on driver side was not functioning & had not been working for some time. SO I did not put it back on. Car never over heats as it always ran pretty cool according to gauge. Would that cause any problems other than overheating? When I turn ac on tuner pro shows yes for both fans.

Plus I can not see the FPR is it under the UIM & thus the UIM must be remove to replace? Anything else I should look at while replacing the FPR.

[robertisaar]

that 4" wire sounds like the fuel pump test wire. if you supply it 12V, it should kick the fuel pump on.

yes, the O2 is VERY rough to get at.

i don't know enough about LQ1s to suggest anything about the studs.

i wouldn't think the fan would cause this issue, but i would eventually try and replace it.

the FPR is also a pain to get at on a LQ1, i can lookup the procedure if necessary, but i do believe the UIM must be removed.

[portsider44]

Well for now I will put the money into the FPR, doubt I can get to it until this weekend. I will post once its done, if there is anything else you can think of while the UIM is let me know, as I would prefer not to remove it again later.

Thanks for staying with my post, as for now I am going to clean up out side & watch the end of game 2 on MNF, plus have a few miller lites. Actually maybe a lot.

[pocket-rocket]

Maybe pull the lower and buy an intake manifold gasket set, since those lowers are prone to leak, causing really crappy brakes (worse than normal thanks to not much vacuum for the booster) and a high idle until it warms up and things swell back up and seal. Also, get a small section of heater hose to replace the one that goes into the bottom of the TB from the tube that snakes from the water pump housing to the TB. I almost guarantee it will not come off in once piece.

Those studs are just supports for the rear of the UIM. They bolt to the rear valve cover.

[portsider44]

I am going to install new FPR, UIM&LIM gaskets & new o2 sensor this weekend. WIth hopes that this will resolve my issues, I will let you how it goes.

[portsider44]

Well got the UIM,LIM gaskets, Fuel Pressure Reg & o2 replace. LIM was in good shape (replace 13 mths ago) but replaced anyways. O2 was a beotch to get too, Had to drop the exhaust & get creative with extensions & swivels. I also replace vaccuum lines as needed.

Bad news I still havent fixed the problem. As after it hit 180 degress it would die when rpms raised. also the new o2 sensor was all over the place, however it did go into closed loop. I had it hooked up to tuner pro but somehow I messed up the recorded log. So I will have to run it again.

Fuel pressure was still high & I am beginning to have more doubts about how accuarte my gauage is. Also it seems odd that it ran good until it reached 180 degrees? Is that when fan #1 would kick on normally? Keep in mind fan #1 has not worked for some time & when I replace the radiator recently I left it off. SO the plug is not plugged into anything.

Also when I would go from idle to lets say 1500 rpms, it would not stay there. It would bounce around & would end up revving higher. Also with a/c on at idle volts would drop to 13.6, w/o a/c would be 13.8-14.

GOing to wiat for it cool down & then will restart & get a tunerpro file. Might even attempt to take it around the block.

[robertisaar]

the O2 going nuts is normal, that means it's up to temp and swinging around stoich, which is a good thing.

and it ran perfectly fine, even at higher RPMs, until 180*F? that is odd.... and may indicate the problem, just have to look through the tune and see what gets kicked on/off at 180*F. what is the 4 letter code on your MEMCAL?

fan 1 should kick on around 220*F, exact number depends on the BCC(4 letter code on MEMCAL).

odd that it didn't want to stay around 1500..... this may also hint as to what the issue is.

[portsider44]

Ok heres the numbers from the ECM

serv no 16149396 AXSJ
862391 M116900665
16162391

[robertisaar]

no a/c
fan 1 on: 226*F
fan 1 off: 221
fan 2 on: 234
fan 2 off: 226

a/c on:

1 on: 224
1 off: 219
2 on: 234
2 off: 226

as for what turns on around 180*F....

carbon cannister purge turns on at 176*F, but shouldn't be commanded at idle.
engine abuse protection kicks on at 176*F as well...

hmm.... that didn't seem to help at all...

[portsider44]

Engine abuse protection?? Would this cause i to kill power to save the engine? If so that could explain why it will idle for ever but under load it dies like a flick of a switch?

Also leaning towards maybe its power issue maybe a bad alternator, bad ground? looking at post from. got it off the jack stands getting to try & take it for a trip around block with tuner pro hooked up & recording this time

[portsider44]

"Now the transmission acts like it wouldnt upshift, it acts like it slips up to ~4000 rpms then the car starts moving and acts like it will not go into 1st gear (like a 2nd gear start)... it was all fine then all at once its jacked up again.... Cash for clunkers is sounding better every day.. OHH and it looks pretty wet under the front head.... Cant see if its coolant or oil... turbo is in the way... Might be time to retire her..."

"my mom's 2000GP used to do something very similar to that..... i think the tranny got too hot and from the way it was explained to me, it was stuck in "long-shift mode"?....... "

Found this in the elec gremlims post problem end up being a ground issue. Long shift mode? ANyway to get it our of this?

I know need to fix my eng problem b4 moving to other issue but I wonder if they could be related?