# 86-87 4x4 z24i code and problems



## Ding1 (Dec 7, 2012)

First off,howdy ya'll..I had a thread started a while ago but couldn't find anything wrong.I have a86/ 87nissan 4x4 TBI,engine was changed out at 100 K by a mechanic so I am not sure what "year" it is.Reg.says 87'.anyhoo I changed everything I could think of,plugs(NGK),wires,cap,rotor,air/fuel filter and O2 sensor,all new vacuum lines,even changed the coils out(new).

I read the codes for a few weeks or so prior to putting the O2 sensor in and it flashed 4-4(normal) but it ran great but climbing a hill or taking off it would cut out AND once in a while it would pop through the TBI.I have been getting terrible gas mileage,used to be around 20-25 mph and although it starts right up,no pumping,idles fine,runs great on flat roads.The code reads 1-1 now since I put the O2 sensor in.Did a fuel pressure test,reads 37 or so but I do smell gas.I checked the injectors,first with engine off,turn key on and I can see "some" gas go into the TBI but stops.no leaking after key is off. checked wiring harness to injectors for cracks,corrosion,shaking it while runningno malfunction

I checked with engine running,and I see what looks as"ripples" on the plate on one side and seems as though it is "smooth" or maybe no fuel on the other side turn it off,no drips/leaks.question,would the crank angle sensor cause all this or the wiring to it.did the finger/diaphram on egr,works.I know this is long winded and to that I apologize.I think I will get it "exorcised from it's demons" but figured someone may have a little more insight.thank you for any and all help.


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## smj999smj (Jan 1, 2006)

"11" is the code for a crank angle sensor malfunction detected. You would need to get a Nissan service manual and go through the Code 11 diagnostic procedure to isolate the problem correctly. NOTE: If a code 11 (crank angle sensor) occurs in a vehicle with manual transmission, clear the memory and repeat the self-diagnosis check. In some vehicles, the code 11 will appear in the self-diagnosis memory any time the ignition switch is turned to the "Start" position while the clutch pedal is not fully depressed.

I would suggest you locate a copy of Nissan service bulletin TS88-077. It'll show you how to do an injector balance test and informs of some issues with the injectors on these vehicles. The fact that you say that the spray from the injectors is different between sides would lead me to think there may be a bad injector or injector harness issue. A timing light aimed at the fuel injectors makes it easier to see the spray pattern due to the strobe affect. You shouldn't see fuel spraying from either injector just by turning the key to the "on" position. You may also want to do an injector leakdown test.


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## Ding1 (Dec 7, 2012)

Thank you S..gives me some insight as to locate and isolate at least an area to look into.I do have the "haynes" manual but it seems under qualified in most spots of interest.I did switch the ignition on without depressing the clutch.I can do this again.What baffled me was that I did the same thing prior(before the O2 sensor) and I received the 4-4 every time.As for the injectors spraying when key is switched on it was only for a second,then it stopped,I assumed it was "natural" to do this to start the truck.There is no leaking afterwards,with key on or off,if that makes sense.I actually don't see any spray pattern.I just remove the air cleaner cover and look down the throat to the plate.I have ran injector cleaner several times through it (lucas) and I will do what ya suggest.At least I have,thanks to you a better understanding on what to do.I was hoping to narrow it down and you helped me pinpoint a couple areas and proceedures to do and I thank you for that S.


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## smj999smj (Jan 1, 2006)

It's hard to see the spray pattern by just looking at it. Using the timing light aimed at it makes it a lot easier to see.


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## Ding1 (Dec 7, 2012)

I found my timing light and am gonna do as you suggested S.Do I have to take the injector cover OFF? I know stupid question and/or is the spray supposed the come through the two slits on the cover of the injectors.I just changed my PCV valve yesterday,not easy like a chevy 400 SB BUT I changed it out and it ran like poop.Got it from auto zone.I thought I had either lost a vacuum hose or pinched one putting the filter housing back on but didn't.I then sprayed everything,around the intake,throttle body with soapy water and no engine decrease or sputter.It ran,that is started up prior to this perfectly,idled perfect and even ran fine prior.What did I miss,it is tight in the fitting housing.It has no fuel leaking in/on the TB plates but I still smell fuel and it still gets crappy MPH.

Should I take the EGR off and clean it,it seems to function(diaphram) manually pushing it up and it springs back down and the engine seems to perform smoother when warmed up,as in idle that is.Again thanks for taking your time to help S.You don't know how much it helps.I'm old school and all I ever did was put oil and gas,tune up etc. with this thing as it was a great rig.


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## smj999smj (Jan 1, 2006)

You don't have to take the injector cover off (only remove the air cleaner housing) and the fuel is supposed to flow through the nozzle of the injector (on the bottom), only. If the engine ran worse with the new PCV valve, perhaps the new valve is bad. If you still have the old valve, spray some carb cleaner through it to clean it up and add a couple drops of oil. When you shake it, you should be able to hear the valve rattle back and forth. Reinstall it and see if the engine runs better. If it does, return the new valve. Carb cleaner is also good for finding vacuum leaks. Sounds like the EGR valve, itself, is okay. You can test the diaphragm using a vacuum pump.


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## Ding1 (Dec 7, 2012)

well I hosed everything down with soapy water AND carb cleaner,no irregularities in engine or vacuum hoses or plugs wires.I hosed out the TBI with carb cleaner.I used the light BUT I put it on the #1 intake wire and nothing,no strobe.I put it on #1 exhaust wire and it worked.Go figure.I could watch the timing mark retard and bounce back to normal.

I will put the old one back on.They both rattled so I am at a loss here.I didn't see anything irregular in the injectors but I couldn't tell with or without the light.I did have a bout of doubt as to WHICH plugs was whut,LOL.I thought maybe I put the "exhaust" in the "intake" and vice versa but I guess they are correct.NGK sumpin sumpin 5's in exhaust and sumpin sumpin 6's in intake.wish the injectors were a little easier to deal with than having to remove the TBI body.As for the EGR valve,I can,with engine running push it by hand and it cuts out but seems to get stuck a little on one side then evens out.May have some carbon build up.thanks S.You've been awesome.


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## smj999smj (Jan 1, 2006)

If you are putting the timing light on #1 intake wire and the timing light is not flashing, you either have the intake and exhaust coils swapped or a dead coil. Try swapping the two coil wires and taking it for a ride and see what happens. The intake side should always fire. The exhaust side fires just slightly after the intake side for more complete combustion (better emissions).


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## Ding1 (Dec 7, 2012)

well took the new PCV out,put old one back(cleaned) and it runs great,well no misses like it did.I changed coil wires,no joy.According to the haynes "best guess" book,standing in front,the #1 intake is on the left side of valve cover and #1 exhaust is or right side.

After switching wires it still won't set the timing light off on #1 Intake.Even switched coils/wires,no joy so I hook the light to the wire,what haynes says is the primary ignition coil wire the light doesn't work,put it on the wire to the other coil and it works.Anyway the truck runs smoother and seems the fuel smell subsided with the old PCV back in.

The dizzy cap has all the markings where each wire goes and they are all GTG.I am having thoughts of where the primary coil is.If I stand in front,I see two coils along side each other.One first then another next to/behind it,THAT is supposed to be the primary coil,the one furthest from the first coil.anyhoo no matter what I do,the timing light works on the right side #1 wire,NOT the left side,by the TBI side #1 intake wire.It starts right up,no cutting out with old PCV,#1 intake wire works,confused to which is the primary coil,it's sunny and warm,neighbor in bikini so it ain't all bad.


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## smj999smj (Jan 1, 2006)

If my memory is correct, it is the rear coil (if you are standing in the front) that is the primary, or intake-side coil. If you are adjusting the timing using the #1 wire on the exhaust side, it will not be accurate. Perhaps your distributor cap is bad? If it has more than 60000 miles on it or if it is an aftermarket cap, I would replace the cap and rotor with genuine Nissan parts. Aftermarket parts don't seem to do well on the Nissan dual-ignition systems for some reasons.


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## Ding1 (Dec 7, 2012)

Wasn't trying to time it S,It seems perfect,no ping or anything,fires right up etc.Trying to see the injectors flow but that is what I came up with with the timing light find what lit it up.It has me baffled.I haven't spent this much time searching for anything since I lost my teeth sitting with a hot ribeye in front of me.LOL
The cap and rotor are OEM parts and about 3 months old,replaced the plugs,wires,cap,rotor,air filter at the same time,tried the PCV valve a couple days ago but kept the old one as it worked better.As for the coil,that is what I though myself,the furthest back.Seems I have 2 injectors in this thing instead of 1 .Question,does the rubber seal that goes to the throttle body,think it is called the throttle body seal,a piece of rubber, have to be air tight.? thus causing an "air leak" so to say and causing a slight idle problem..It says to use silicone seal to seal the rubber throttle body seal.I have had the air cleaner case off many times and have noticed the rubber seal and never paid much attention to it.There is an aluminum oblong ring withe two stem that the locking screws fit through,it sits under that ring.I bough one new coil and didn't get the other one yet,the old one seems to work as it idles fine.Thank you S.I'll get it figured out by the time 53rd president is elected or else.


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## smj999smj (Jan 1, 2006)

I don't believe that particular seal will cause an idle issue. Usually vacuum leaks that affect the NAPZ engines occur at the intake manifold gasket or the throttle body base gasket. But if one of the injectors isn't firing right, that's an issue as well. There are two injectors (and they are somewhat expensive, last time I checked) and they flow simultaneously. So if the spray patterns are different between the two, there is an issue with them.


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## Ding1 (Dec 7, 2012)

Yeah the injectors are like 300+ a piece at auto zone.I think I will pull the TBI off,get a rebuild kit/gaskets for the TBI body and O rings for the injectors,get the injectors cleaned/tested.Maybe I can test em,the harness that is up to the second half plug.I hear on these z24i's that they spliced some or some such thing in the harness.Just cut it open length ways and look for corrosion,fix splice if needed and test the output to the injectors.

I did look at the throttle plates again.One side looked as though it had "ripples" on the plate like it was getting a heavier spray or squirt as it were while the other side looked smoother,getting gas/spray.Might as well do that and change all the fluids in the transfer case,front and rear diff,and trans whilst I'm at it.I love this truck,had it for 23 years,no problems but one,a head gasket.Been to places that scared guys on ATV's in it.I can't thank you enough S for all the help and just talking with me.


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## Ding1 (Dec 7, 2012)

Question.Just looked at my engine number ( Z24 365886) cannot seem to find the year for it.The reg/vin, says 87' but I think the engine was changed out.I am having problems with some parts not matching up when I get em home.Is there some place to find the year of the engine.I always say 87' z24i when the parts guy asks but when I get to replacing the injectors,as I thought I may either replace em or rebuild em with new O rings and TBI gaskets, it says it takes one injector but I have a duel injector set up.Confusing to say the least.
Also there seems to be a leak in my throttle up sensor,smells of fuel around the wires coming out of the unit when I touch it,small amount of black oily grime in a small section of the 2 wires where they come out of the sensor but smells of fuel.Should I just replace it,does it affect anything like it cutting out and do the TBI rebuild.No codes on the ECU other than 44 on the self diagnose mode III.


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## Ding1 (Dec 7, 2012)

well been tracing everything I can.Took the harness wrap off the wiring,not one splice anywhere as per the thread about splices causing injectors to be erratic..Got a stethoscope and listened to the injectors,both working.Can hear them clicking.Used propane and carb cleaner around intake body,no change in idle.

Have all new vacuum lines,checked the EGR valve diaphram by pressing on it while running and it cuts out,plug wires(8 MM double insulated),new cap,rotor,NGK plugs,air filter,Got a gizmo that lights up on the plug wires pulse,no missing/erratic pulses,My timing is @5 degrees instead of 10* though.The idle is a little off,like a miss when first fired up but is better after warming up,terrible gas mileage.Figured this is due to the timing being off 5* but will change that tomorrow to 10*.Still no codes,just 44 although I did get a 1 time code 11(TPS) but attributed it to just turning the key on without pushing in the clutch as when I redid by depressing the clutch and turned key the code went away.Am I missing something here.Am I looking in or at the wrong things.


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## Ding1 (Dec 7, 2012)

took the MAF sensor off and cleaned it with some alcohol and it improved some but was afraid to really get into the little posts and wires.I just read that there is some spray MAF cleaner.Do you spray that into the TB or take the sensor off to spray it clean.Those little posts and what looks like wires make me nervous to touch.The idle did improve after some scary cleaning but I'd like to really clean it good.


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