1994 Q NO POWER WHEN WARM HELPPPP

[JOSHIE88]

ok guys ive been reading on here for months tryin to figure out this problem with little luck

i have a 94 q with about 125k ran really good burn rubber when everthen it started to stumble at idle took it to my mechanic and figured out 3 injectors were bad so i had them changed with oem ones then did a tune up too.. plugs changed the fuel filter changed oil air filter all the little basics

then about 5 months ago it started running kinda funny on the freeway it felt like it was lacking powerand would stall and turns out the fuel pump was not putting out enough pressure so i changed that that made it almost back to normal

recently its doing almost the same thing but doesnt stall its weird when its cold it runs perfectly once it warms up its hell to drive. it idles fine and i ohm checked the injectors they all check out fine. oh and it uses stupid amout of gas im getting roughly 9 miles to the gallon anybody have ideas?

ive checked to FPCU all injectors ohm out goodcleaned the maf sensor cleaned the throttle body checked the plugs look fine gaps are goodim kinda spinnin my wheels now

my ideas(just ideas)maybe clogged cats maybe fuel pump went out again idkany help please throw it out there

thanks Josh and since im new ill post some pics of the q




Modified by JOSHIE88 at 9:31 PM 6/20/2009

[Infinitiguy19]

Try these procedures:





You can also try OHMing the Knock Sensors which it what I bet it is: http://q45.org/ohminjectors.html

Is your car a Q45T?

Welcome to NICO.

Love the wheels.

[JOSHIE88]

THANKS YEA ILL TRY THOSE TOMORROW SEE HOW IT GOES THANKS

[elwesso]

I'd lean toward a MAF related problem..

[maxnix]

Perhaps, but you must confirm fuel pressures under operational conditions.

[lino]

Welcome to Nico

What size wheels and tires are you running?

[JOSHIE88]

IM NOT SURE OF THE OFFSETS BUT THE FRONTS ARE 20X8S AND THE REAR IS 20X10.5...THEY WERE OFF A G35 COUPE

[JOSHIE88]

ALRIGHT SO HERES THE DEAL

THE FUEL PRESSURE WAS FINEIT WAS NONE OF THE THINGS ON THE FIRST LIST

BUT WHEN I OHM CHECKED THE KNOCK SENSORSI LEFT THE MULTI METER ON THE SETTING I USED TO DO THE INJECTORS I DIDNT GET A READING... SO I CHANGED IT TO 40M AND I GOT A READING OF BETWEEN 4.9 AND 8.7 ON THE RIGHT PIN AND NOTHING FOR THE LEFT PIN IM NOT SURE WHAT THIS ALL MEANS

IM NOT A WIZ AT A MULTIMETER SO CAN SOMEONE PLEASE TRANSLATE LOL

THANKS =]

[goody90q45]

Did you switch voltmeter probes to ohm the KS? For a 94 it should be engine off, key out, neg probe of voltmeter to neg post of battery, pos probe of voltmeter to lower pins of 6 pin KS harness. The reading should be about 550,000 ohms resistance so if you're reading is some multiple of 5 you're in the ballpark (i.e. my voltmeter reads 550 so I multiply by 1000).

If it's reading 0 you have a dead KS but that's probably not the problem with the poor acceleration you're having. I've had a dead KS on my 94 for 4 years and she accelerates like there's no tomorrow. CEL on? Have you pulled codes? Smooth at idle? Don't write back if you haven't already changed the fuel and air filters ( ). Did you replace injectors with new or junkyard (sitting for a long time) used. Could be partially plugged injectors. Try a bottle of Redline S1 fuel system cleaner in a half tank of gas and see how she feels in a week.

[JOSHIE88]

ALRIGHT THANKS FOR CLEARING THAT UP WITH WHERE THE VOLT METER PROBES GO ILL GO TRY IT AGAIN RIGHT NOW

YES THE AIR FILTER IS BRAND NEW AND THE FUEL FILTER WAS CHANGED 5 MONTHS AGO OR SO

THE CEL CAME ON FEW WEEKS AGO BUT THAT WAS CAUSE AN INJECTOR WAS BAD I GOT LUCKY TOO IT WAS THE #2 INJECTOR I REPLACED WITH A NEW OEM ONE...IT HAD A ROUGH IDLE BEFORE THAT AND WAS CORRECTED BY THE NEW INJECTOR AND THE LIGHT WENT OFF AND HASNT COME ON SINCE

AND THE REDLINE STUFF IS IT SPECIAL STUFF I HAVE TO FIND LIKE ONLINE OR DO THEY HAVE IT AT LIKE PEPBOYS AUTOZONE TYPE OF PLACE

THANKS

[JOSHIE88]

I MADE A TYPO IN THE LAST POST IT SHOULD SAY "40K" NOT "40M"

I JUST DID IT AGAIN THE WAY YOU SAID TO AND I ONLY GOT A READING WITH THE METER ON 40M THE RIGHT PIN SAID ABOUT .74

THE LEFT PIN THE NUMBER WOULD GET BIGGER TIL IT REACHED 40 AND THEN WOULD SAY ERR TRYED SWITCHING THE DILE THING TO THE OTHER POSITIONS AND COULDNT GET A READING SO I ASSUME THE LEFT PIN WOULD CLIMB TO 55 MAYBE LOL

SO DOES THIS MEAN THE KS ON THE RIGHT PIN IS DEAD?

THANKS =]

[goody90q45]

.......I JUST DID IT AGAIN THE WAY YOU SAID TO AND I ONLY GOT A READING WITH THE METER ON 40M THE RIGHT PIN SAID ABOUT .74

THE LEFT PIN THE NUMBER WOULD GET BIGGER TIL IT REACHED 40 AND THEN WOULD SAY ERR.......

I want to make sure we're talking about the same two pins as shown in the pic.



I thought the KS read 550k ohms as a minimum and went up from there to infinite resistance as they failed. The right side pin reading 74 sounds like it's in the process of failing and the left side pin rising to 40 before reading err shows that it has infinite resistance and is dead also. Then again, I'm not familar with the 40M setting on a voltmeter so the problem could be just finding the correct setting.

.......AND THE REDLINE STUFF IS IT SPECIAL STUFF I HAVE TO FIND LIKE ONLINE OR DO THEY HAVE IT AT LIKE PEPBOYS AUTOZONE TYPE OF PLACE.....

I get mine at Pep Boys but noticed that the local Napa started stocking it couple of weeks ago.

.....CAUSE AN INJECTOR WAS BAD I GOT LUCKY TOO IT WAS THE #2 INJECTOR I REPLACED WITH A NEW OEM ONE.....

Hopefully you bought a lottery ticket that day also. It would have been a winner.

Your Q looks familiar. Did you buy it from an owner in NorCal and/or a NICO member?
Modified by goody94q45 at 12:42 PM 6/21/2009

[maxnix]

Please, IT IS NOT NECESSARY TO SHOUT AT US!

Thank you.

[maxnix]

ALRIGHT SO HERES THE DEAL

THE FUEL PRESSURE WAS FINE

Please describe "FINE" quantitatively with fuel pressure in psi numbers for WOT while underway and idle .

[JOSHIE88]

ALRIGHT...haha

so "FINE" being around 35psi at idle and 46ish psi at WOT +unless those numbers would change under load i just checked it with the hood open

yes those were the pins i ohm checked... i figured the right pin 0.7- was going out since thats just about 0 when its supposed to be 550... and as far as the other pin it might be my ohm meter not being able to read that high so it goes off its scale ill see if i can borrow my friends see what it reads on his

yea i got super lucky with the injector should of bought a lotto ticket

and i noticed when i went to move my car right now that the CEL was on it might be because i unplugged the knock sensors with the key on ya?

and ill forsure try a bottle of the redline cant really hurt to try it right?:

no i got the q off a kid that drove it from kansas and parked it when he got here<souther cali> he was asking 1600 for it got it for 1000 washed it buffed it out looks pretty good in person the car was pretty much bone stock when i got it had some after market 15 inch wheels on it a cracked windshield and the power steering was gone. got a wind shield for 170 and 75 for the ps pump and it was all good for a while... i lowered it with the espillar springs tanoko blues then got the wheels painted them black tinted the windows put a stereo in it and the interior is all redone with black carpet and swead dimond tuck inserts and swead headliner havent gotten to take any good pics of the interor yet but i will when i get a chance

Modified by JOSHIE88 at 4:50 PM 6/21/2009
Modified by JOSHIE88 at 4:51 PM 6/21/2009

[JOSHIE88]

changed the knock sensors today and its a whole new car!runs 10 times better

[TBrack]

good to hear another Q problem resolved.

What brand wheels are those? They look like EXE.

[JOSHIE88]

yea im pretty stoked!

im honestly not sure they are 3 piece wheels my friend had laying around in his garage he said they were on a g35 coupe or 350z