Fuel Injector Cleaning

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

Q45tech wrote:No.1 -43RPM??????????? Dirty injNo.2 -8RPM***********severe dead No.3 34RPM???????????? Dirty injNo.4 -1RPM************severe deadNo.5 52RPM OKNo.6 74RPM OK.......................74 minus 25=50 minimumNo.7 62RPM OKNo.8 18RPM***************bad dirty inj

All power balance readings should be no more than say 12-25 rpm variance..............perfect readings would all be +- 12 rpmKNOCK SENSOR 0 {FAILED TEST ZERO CRANKS AGO}INJECTOR LEAKS 25 {FAILED TEST 25 Cranks ago

CMPS-RPM(POS) 913 RPM *********RPM out of spec 750 rpmCMPS-RPM(REF) 909 RPMMAS AIR/FL SE 1.49 *********at 750 rpm expect 1.2-1.24 volts

Some dead injectors or fouled plugs [ignition coils] #2  dirty injector #8.

AAC/V OPEN0% 840RPM should be 550-625 rpm or so [with 20% 846RPM should be 700-750 rpm80% 1504RPM ok probably 100 rpm too high.

Shows that somebody misadjusted the air bypass screw and the unit is dirty [TB/pcv hoses/valve].

Tech, I would have never guessed. My car war running so smooth before this except when you saw my car with the dead rat on the engine block! So basically I need brand new injectors on 2,4 and 8, cleant the other misfiring, knock sensors, and adjust the air bypass screw(which I do remember being adjusted not exactly to spec which would account for the intermittent engine light). If the knock sensor is replaced then the voltage for the air sensor should return to normal correct. It's brand new unit purchased in July 5th 2003.

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

Are my O2 sensors functioning at the right voltage? At .91 they appear to be. Is this directly because of the misapplication of the fuel injector cleanr through the vacuum intake? I'm trying to show a correlation if there is one to be compensated.

Post by **elwesso** » Tue Oct 07, 2003 9:58 am

Again, putting FI cleaner in the intake wouldnt do anything to the injectors, because it doesnt in any way get near the injectors......

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

elwesso wrote:Again, putting FI cleaner in the intake wouldnt do anything to the injectors, because it doesnt in any way get near the injectors......

I understand that but what I was trying to say is that there has to be a correlation between the process and my knock sensors/O2 being thrown off. That was my conclusion. It may have needed replacement and I didn't know but the incorrect process may have speeded it up exponentially.

Post by **Q451990** » Tue Oct 07, 2003 9:58 am

My theory is that the injector cleaner loosened up something and fouled out your spark plugs and O2 sensors. I can't think of any way the knock sensors would be related.

Heath

Post by **maxnix** » Tue Oct 07, 2003 9:58 am

Q451990 wrote:My theory is that the injector cleaner loosened up something and fouled out your spark plugs and O2 sensors. I can't think of any way the knock sensors would be related. - Heath

Amen. could have dumped a lot of crap from the vacuum line/intake path into the cylinder. Probably couldn't have affected the knock sensors without overheating the engine.

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

Q451990 wrote:My theory is that the injector cleaner loosened up something and fouled out your spark plugs and O2 sensors. I can't think of any way the knock sensors would be related.

Heath

True, but the computer at the dealer says they are failing(see up). Can a faulty O2 bring about a false 34 or knock sensor code?I'm asking because I could save alot of money this week. I have the O2 sensors from sparkplugs.com on the way so I want to make sure I have all my bases covered. Maybe I should just replace them anyway.

Post by **maxnix** » Tue Oct 07, 2003 9:58 am

I would think it would be wise to fix the injectors, fuel filters, knock sensors and everything else first. Run it, then run a consult. If still indicating O2 sensors, then replace.__________________Brian1995 Q45 & Q45t & 2000 Q45

Discover the power of the button!

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

maxnix wrote:I would think it would be wise to fix the injectors, fuel filters, knock sensors and everything else first. Run it, then run a consult. If still indicating O2 sensors, then replace.__________________Brian1995 Q45 & Q45t & 2000 Q45

Discover the power of the button!

Funny thing is that in the diagnostic the O2 sensors are not showing up as being faulty. I need to replace them (105,000mi)any way. A couple of injectors can be cleane except for the obe that show severe. I'll have to wait for that because $141 apiece and two knock sensors at almost $250 is not going to make unless I hit Lotto.

Post by **Q45tech** » Tue Oct 07, 2003 9:58 am

The Consult and engine ecu is very dumb without a brillant technican to interprete the results.

The Consult say ok as long as something is happening or as long as the sensor signals are not zero or 5.0 volts....[some where in between].......it is just a window thru which you see what's happening.

Dealer techs learn from years of seeing the voltages at idle and cruise conditions to know what is right and wrong.

Unless a technican has taken the time to monitor WOT accelerations and record reems of data they don't know what is right and what is wrong under these conditions.

As to the MAF it just measures air flow and the air flow should be the same at specific throttle positions [10-100%] and rpm [within 10% for dirty intake track/valves, etc. Vacuum leaks can throw the numbers off at low to cruise rpm when the air flow is only 10-15% of maximum.

MAF voltage must be very very close to 1.22 volts [1.15-1.3 volts] at the right idle rpm when at operating temperature.

If not we swap the MAF and monitor the results for changes [bad MAF].

These engines are not complicated as very few sensors, the same as all others of the era. Failure to diagnose correctly indicates a defect in the technican!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

Q45tech wrote:The Consult and engine ecu is very dumb without a brillant technican to interprete the results.

The Consult say ok as long as something is happening or as long as the sensor signals are not zero or 5.0 volts....[some where in between].......it is just a window thru which you see what's happening.

Dealer techs learn from years of seeing the voltages at idle and cruise conditions to know what is right and wrong.

Unless a technican has taken the time to monitor WOT accelerations and record reems of data they don't know what is right and what is wrong under these conditions.

As to the MAF it just measures air flow and the air flow should be the same at specific throttle positions [10-100%] and rpm [within 10% for dirty intake track/valves, etc. Vacuum leaks can throw the numbers off at low to cruise rpm when the air flow is only 10-15% of maximum.

MAF voltage must be very very close to 1.22 volts [1.15-1.3 volts] at the right idle rpm when at operating temperature.

If not we swap the MAF and monitor the results for changes [bad MAF].

These engines are not complicated as very few sensors, the same as all others of the era. Failure to diagnose correctly indicates a defect in the technican!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Bad techs are common here. Or not really bad but thirsty for money. I will still change the knock sensors per the readings, O2(time for it 105,000mi) and clean those injectors you said were still functioning but dirty, The bad ones I'll have to change in about a month. My MAF is only a few months old. Maybe I should swap for another MAF.

Post by **elwesso** » Tue Oct 07, 2003 9:58 am

You could tow it to the indy meet and we'll have a group DIY!!!!!

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

elwesso wrote:You could tow it to the indy meet and we'll have a group DIY!!!!!

I wish! We need to organize more meets. I'm just trying to save money and not replace something(that I can wait on. Oh well. The price of luxury!

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

elwesso wrote:You could tow it to the indy meet and we'll have a group DIY!!!!!

Don't rub it in!

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

Is it possible I have a possible bad TPS? My RPM was above 1000 at idle before the melee.

Post by **Q45tech** » Tue Oct 07, 2003 9:58 am

The TPS almost never fail [they may have dirty bad spots along the path [idle to WOT] [just as the radio volume control cracks and pops when turned and dirty].

TPS may be mis set at idle [0.4-0.45 volts] as seen by ecu and reported by Consult.TPS connectors/sockets may have corrosion and be intermitent.Mis adjusted throttle cables or mis adjusted cold idle stops [warm up wax dashpot] can improperly set allowing the throttle not to close perfectly and thus the TPS voltage will be higher [0.5-0.9 volts].

It is pretty much impossible to diagnose a modern engine without the appropriate scan tool because you cannot get to the sensor signals easily vs viewing them all in 5 minutes with a Consult. A tech without one is guessing and even if he is able to rig up a volt meter pretty hard to run the wires in side and view while driving down the road. Pull over and check another sensor ......You could spent 8 hours trying to gather the data the Consult does in 5 minutes.

There are things the Consult can't see: fuel pressure, engine plenum vacuum, exhaust temperature and back pressure, knock sensor real signal [retard], oil pressure, etc.These require other test equipment which should also available.

This is the bane of the small independent [not having the correct scan tool and adapters] who works on every car that comes by!

Most cannot even check the timing because they don't have the adapter.

Kind of like a doctor without a thermometer or a stethoscope or blood pressure gauge or EKG!

Owners pretty much get what they deserve when selecting a generic shop!

Post by **VenCountyQ** » Tue Oct 07, 2003 9:58 am

"Most cannot even check the timing because they don't have the adapter."

Just wanted to take this opportunity to evangelize about the timing check wire hanging off the power transistor on many Q45s. Wonderful feature that Nissan designed which makes the special adapter completely unnecessary.

Post by **Q451990** » Tue Oct 07, 2003 9:58 am

Q45tech wrote:...engine plenum vacuum...

By the way,

I haven't forgotten about checking this. As soon as I can find that vacuum gauge, I'll check both Q's for you.

Heath

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

Q45tech wrote:The TPS almost never fail [they may have dirty bad spots along the path [idle to WOT] [just as the radio volume control cracks and pops when turned and dirty].

TPS may be mis set at idle [0.4-0.45 volts] as seen by ecu and reported by Consult.TPS connectors/sockets may have corrosion and be intermitent.Mis adjusted throttle cables or mis adjusted cold idle stops [warm up wax dashpot] can improperly set allowing the throttle not to close perfectly and thus the TPS voltage will be higher [0.5-0.9 volts].

It is pretty much impossible to diagnose a modern engine without the appropriate scan tool because you cannot get to the sensor signals easily vs viewing them all in 5 minutes with a Consult. A tech without one is guessing and even if he is able to rig up a volt meter pretty hard to run the wires in side and view while driving down the road. Pull over and check another sensor ......You could spent 8 hours trying to gather the data the Consult does in 5 minutes.

There are things the Consult can't see: fuel pressure, engine plenum vacuum, exhaust temperature and back pressure, knock sensor real signal [retard], oil pressure, etc.These require other test equipment which should also available.

This is the bane of the small independent [not having the correct scan tool and adapters] who works on every car that comes by!

Most cannot even check the timing because they don't have the adapter.

Kind of like a doctor without a thermometer or a stethoscope or blood pressure gauge or EKG!

Owners pretty much get what they deserve when selecting a generic shop!

Yeah you're right about generic shops. So hard to find good techs/mechanics in NYC well versed in Q45's. Very frustrating. I know this week I want to order these knock sensors so I can have them by Saturday. O2 sensors which showed up at 0.91V (normal?) are still back ordred for weeks. I'm gonna clean the throttle body, PCV, adjust air bypass screw and hope the rich condition I have will be corrected. However, as it was explained to me, the knock sensors have nothing to do with the Mass O2 sensor reading rich. I need to evaluate what you said about vacuum leaks. Makes alot of sense.

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

Sorry for the delay but business is busy. What happened is that the brand of cleaner used looks identical to one another. So we were under the impression that the fuel cleaner went through the vacuum line. What they used was an intake cleaner that the manufacturer stated was good for cleaning the line. The dirt was probably immense and threw the O2 and knock sensors off. The problem has reversed. The car no longer burns rich, gas mileage has returned to near normal but the car is still vibrating a little rough at idle or at a stoplight. Dont know what that is but this is very strange that a intake cleaner would have made the Q go haywire. I guess the product itself was to blame? Who knows. Thank you guys much. I'm still going to investigate. In the meantime this fuel pump is about to be history. And I'm changing the plugs again as they may well be fouled as stated here. Can you guys believe that a mechanic I kno says he can change the plugs in about two hours!? Whatever! I bet at least four and a half.

Post by **elwesso** » Tue Oct 07, 2003 9:58 am

So they used a cleaner that was meant for the intake tract, correct??

Anyway, it sounds good.....

Rough idle (is it too low?) is probably IAC needing cleaning......

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

[QUOTE]Originally posted by elwesso "]So they used a cleaner that was meant for the intake tract, correct??

Anyway, it sounds good.....

Rough idle (is it too low?) is probably IAC needing cleaning...... [/QUOSupposedly. They're were two bottles linked toghether. One was placed in the tank the other through the intake. So he may have placed the right bottle in it's just that the procedure may have not been applied correctly. The rpm's are fine. I think I may need new mounts (transmission/engine). I'll check IAC too.

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

Wait till you see how the boysenberry Q looks now!

Post by **DAEDALUS** » Tue Oct 07, 2003 9:58 am

OLU40 wrote:Can you guys believe that a mechanic I kno says he can change the plugs in about two hours!? Whatever! I bet at least four and a half.

I think Chally has stated that's how long it takes him as well. It takes me 3-4 hours, but I like to take my time and look around anytime I'm under the hood.

Post by **elwesso** » Tue Oct 07, 2003 9:58 am

He must not be very tall, cuz when I work on the Q I have to stretch every 10 mins or so.....

Post by **OLU40** » Tue Oct 07, 2003 9:58 am

We shall see!

Post by **VA99Q45** » Tue Oct 07, 2003 9:58 am

OLU40,

Did you fix your rough idle problem?

Fuel Injector Cleaning

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