# 88 HB Z24i - wierd engine behavior



## foxkw (Dec 26, 2008)

hi folks -my 88 Z24i 2WD has started exhibiting a wierd engine behavior as follows: it will start run and drive fine if you don't push it but the minute you put an instantaneous increased load on lit (Step on the gas) it starts bucking and dying. If you back off the throttle sharply, it will come back to life, it feels like a rev limiter or a serious ignition miss fire. I haven't had an opportunity to check any computer codes yet because it's been raining (not a contributing factor) and I have to pull the bench seat out to get at the computer. 

I have the official manual (Nissan) but there doesn't seem to be a driveability diagnostic for the motor like the one for the automatic transmissions. 

I don't think it's a failed airflow sensor at this time because although it doesn't have a tachometer it's definaitely operating OK above 2000 RPM and 2800 RPM (the failsafe mode limits) - because I've had it going 70-80 on the freeway even though it took a while to get it up to speed. Additionally when travelling at any speed if you push on the throtlle past a given (variable) point it will exhibit the problem -- the problem will show up at a variety of physical throttle angles. 


unsuccessful remediations attempted so far: 

1. replaced the distributor cap and rotor - the cap had to be replaced anyway because the Intake side coil wire tower (as labeled) was broken and corroded.

2. Replaced the fuel filter

3. Checked that all of the connections were secure. 

my guesses as to what the problem might be: 

1. A faulty Intake side coil or power transistor because under load the computer cuts out the exhaust side ignition to reduce engine rumble according to the service manual, and if the intake side ignition circuit is faulty then it would be just like shutting the ignition down. 

2. sticky or defective fuel injector. 

Any suggestions or help would be appreciated.


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## zanegrey (Dec 5, 2005)

all that and you did not just read the codes..

READ THE CODES..

AND CHECK THE SECONDARY COIL.


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## minitrkingking (May 10, 2009)

My truck does the same thing exactly, I have a vacuum line that is rubbed through, could this be the cause?


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## zanegrey (Dec 5, 2005)

u could not just fix the hose and find out for ur self??


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## minitrkingking (May 10, 2009)

I could zane but what's the fun in that?


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## foxkw (Dec 26, 2008)

It's been raining pretty hard around here lately and for the reg cab swb 2wd I have to pull the whole bench out to get at the computer. COdes however are the next step.
OTOH I have a camry which says that it's camshaft position sensor is defective and the engine doesn't have a camshaft position sensor... ;}


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## foxkw (Dec 26, 2008)

zane - just curiouis why the secondary coil? I'm off to the automotive boneyards tomorrow to look for parts for the camry and the nissan. Not a lot of Z24i motors around here....(at least that I hace found)


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## zanegrey (Dec 5, 2005)

the cs sensor is most likely in the dizzy..

just check the coils to see if they are sparking...


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## foxkw (Dec 26, 2008)

would the crank sensor cause problems starting after it's been raining for a while because the other day after days long down pour the thing would crank but wouldn't catch and run. It would backfire and stop cranking though. The crap weather should be outta here tomorrow so I'll get a chance to read the codes then. 

Thx


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## foxkw (Dec 26, 2008)

Another question - any other Nissan vehicles use the same coils and power transistiors that the Z24i uses? looking for alternate donor vehicles, if that's the problem.


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## zanegrey (Dec 5, 2005)

what codes did u get ???


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## CMax03 (Jan 17, 2009)

It's that secondary coil....I bet my balls in it! The seconadary turns on during part throttle, Off during full throttle and back on during decel/off throttle!


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## zanegrey (Dec 5, 2005)

c please no betting ur balls..


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## minitrkingking (May 10, 2009)

You can get like 60k for you balls as medical research, don't waste them on a bet


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## CMax03 (Jan 17, 2009)

I've got really good balls so maybe $120K!! LOL...How about how that truck is runnning Foxkw?


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## zanegrey (Dec 5, 2005)

AND everything is bigger in texas...


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## foxkw (Dec 26, 2008)

my cat as several balls,,, the dog lost his. (


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## foxkw (Dec 26, 2008)

CODES - Not sure if I got them right here's wwhat I did:
turn ign on
turn diag switch on
numbers that follow (red & green blinking together)
4
5
1
2
3
I think they are grouped as follows 45, 1, 23 or 45, 12, 3 
I don't think I am reading the numbers right or performiong the procedure correctly.

45 seems to be a leaky injector.


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## foxkw (Dec 26, 2008)

C - 88 2wd reg cab HB z24i AT 180K Mi.


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## zanegrey (Dec 5, 2005)

5 4 3 2 1 are the modes.. u want mode three..

so after it blinks three times turn the switch off and then record the codes...


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## foxkw (Dec 26, 2008)

*solved?*

Intake side coil is/was bad.

I thought the spark was either weak or non existant on the primary side. an interesting observation is that the engine will run on the exhaust side ignition circuit alone. 

After poking around, I disassembled the coil units and ohmed out the coils and tried to decipher the ignitors. Strangley, both coils had the same readings on the VOM. I needed to verify that there was an ign signal going to the primary coil and since I knew the exhaust side coil & igniotor were good I put the intake coil with the exhaust ignitor and found ... no spark. putting the exhaust coil with the intake ignitor resulted in a spark. 

Took it for a test drive and the problem was gone. Now I need to find a coil for it. This is a list of potential donor cars: 

NISSAN 200SX (1987 - 1988) 
NISSAN 720 PICKUP 1986 
NISSAN D21 PICKUP (1986 - 1989) 
NISSAN MAXIMA (1987 - 1988) 
NISSAN PATHFINDER (1987 - 1989) 
NISSAN PULSAR NX XE (1987 - 1988) 
NISSAN SENTRA 1988 
NISSAN STANZA (1987 - 1989) 
NISSAN VAN (1987 - 1988) 

:fluffy:


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## zanegrey (Dec 5, 2005)

they are not that expensive from the parts store..


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## 95Partfinder (Nov 2, 2009)

just a WAG (wild ass guess) throttle position sensor? seeing as how its when you get on it that the trouble starts.


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## foxkw (Dec 26, 2008)

*Coil(s)*

Zane - At the yard I can pick up more than one if I can find it plus I'm going to look around for some of the other bits that could be problems like the TPS, CPS, Power Transisitors, fiel injectors, and crap like that. Plus the JY is only going charge me $2.00 for the coil. Autozone wants $34.00 special order plus State sales tax. Being broke & unemployed makes me save money where I can - besides a junk yard is like Bloomingdales to me 

It's always good to have spares seeing as I haven't seen many Z24i motors or pickups in the yard in the past couple years. Seems like all of the pathy's in the yards are v6's. 

95 PartFInder - swapping the coil solved the stumble problem completely although I can tell it's not quite right with the seconday (exhaust) coil being defective. 

I think there are other issues though (leaky injector, AFS on its way out, and so forth) - this thing was not well taken care of before I got it. It had been parked outside for 5 years, and was covered in green fur (mold) about 1/4" thick. SInce then it's been by my two stepkids - Clutch Slayer and Brake Slammer... it's been pretty durable though..


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## zanegrey (Dec 5, 2005)

NISSAN 720 PICKUP 1986 
NISSAN D21 PICKUP (1986 - 1989)
NISSAN PATHFINDER (1987 - 1989) 

assuming they all have the z24 engine..


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## minitrkingking (May 10, 2009)

What is another name for the secondary coil? I am going to pick up some hose and should probably do this at the same time.


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## zanegrey (Dec 5, 2005)

exhuast coil...


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## foxkw (Dec 26, 2008)

I cross referenced the replacement part numbers from RockAuto before I went to the junk yard. 

NISSAN 200SX (1987 - 1988) 
NISSAN 720 PICKUP 1986 
NISSAN D21 PICKUP (1986 - 1989) 
NISSAN MAXIMA (1987 - 1988) 
NISSAN PATHFINDER (1987 - 1989) 
NISSAN PULSAR NX XE (1987 - 1988) 
NISSAN SENTRA 1988 
NISSAN STANZA (1987 - 1989) 
NISSAN VAN (1987 - 1988) 

I think that the coil from an Infiniti G20 will work as well since they share the crank position sensor assembly. (I got a couple from the junk yard today)

Still need a Crank sensor and also a distributor for the 96 Camry. DId find (at last) a passenger door for the Camry DX Coupe. so the trip was a winner...


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## Chango (Aug 13, 2009)

I know it sucks for you that your truck was running like poop, but it has worked out for me because mine started doing the exact same thing today. As in, when I parked it Friday night after getting home from work it ran fine; then when I left for work today it ran like crap after sitting still all weekend. I haven't even had a chance to check the codes because it only started doing it on my way to work. Well, I guess I could have tried checking them instead of replacing the fuel filter on my last break, but what fun would that have been?

I should probably check the codes anyway. So far I've been taking the attitude of "The check engine light is on, so I popped the hood open and it was still there."


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## foxkw (Dec 26, 2008)

CHango - Depends what year and model you have -- the Z24i motor has 2 spark plugs per cylinder and two ignition coils. 
The easy spark check if to pull the coil wire or wires off the distributor cap (one at a time) hold them or place them near a good ground, crank the motor, and watch for a spark. No spark means there's something wrong with some element in the iginition circuit. In my case it turned out to be the coil but it could have been a lot of things.


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## zanegrey (Dec 5, 2005)

o i just hate to say thanks ....i'd rather go look something up ..

cough cough....


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## brookwood61 (Aug 18, 2005)

One quick check if something sits in rainy weather for a few day, or even overnight and won't start, is to spray the plug wires,cap and all, with cheap hairspray, from an aerosol can. If it starts, change the wires and cap. You should be able to even feel the dampness/coldness in the wires if they are bad.
Good Luck


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