KA issues

[BluDimer]

Hello ratsun,

 

I've already post in the engine section, but not sure this could be a electrical wiring issue as well. If not please let me know and i can delete or moderate can do as well.

 

 

 

I have a (91-94) KA24DE in a datsun510. Everthing works great until I attemp to do some wiring and hose clean up.

 

What i have done:

 

• remove and plug PCV with thread bolts under the intake.
• Insert and filter into the PCV outlet.
• Cut and clean up heater hose and non-use vacuum connection under bottom intake.
• Ran heater hoses direct to heater core.
• Check as carefully as possible and cut, shorten, and solder all connections.
• Relocated stock fuse box inside the cabin.

 

 

Now the with key on I can hear fuel pump on as it is priming gas. Then it stops I then start the engine and it fire right up with no problem. Idles for a bit then slowly blogs then dies.

 

What I have checked and replaced:

 

• Fuel filter
• Mass air flow meter
• Fuel pressure regulator read 14-16 psi of vacuum.
• Check wiring again as what I know.
• My IACV AAC does not have the EGR sensor wired.
• My IACV AAC does not have the EGR two wires wired.
• My IACV AAC does not have the brwn and sliver dot connected before or after the issue.

 

I’m stumped here and really need some professional help. I want to get this car running again.

 

Thanks,

 

BluDimer

[q-tip]

Is you iacv hooked up to the intake post maf, and the pcv not plumbed into it

[BluDimer]

Is you iacv hooked up to the intake post maf, and the pcv not plumbed into it

 

The only change is it PVC filter and removal from bottom of top intake. Thank you.

 

[INDY510]

How soon does it die after start-up? .... is it the same on every start up??

 

My car was going into the fail safe mode for the ECU .. . it would die about 4 seconds after start up every time .. unless the MAF plug, at the air filter, was dissconnected, and I kept the idle up, then it would run all day... but obviously not good enough to drive

 

I tried a used MAF, re-wired the whole harness, and checked everywhere for vacuum leaks .... . . but a $40 used ECU off ebay fixed the problem , 6 months later.. :mad:

[q-tip]

Try just running the iacv from intake and letting the breather on the valve cover just vent

[BluDimer]

How soon does it die after start-up? .... is it the same on every start up??

 

My car was going into the fail safe mode for the ECU .. . it would die about 4 seconds after start up every time .. unless the MAF plug, at the air filter, was dissconnected, and I kept the idle up, then it would run all day... but obviously not good enough to drive

 

I tried a used MAF, re-wired the whole harness, and checked everywhere for vacuum leaks .... . . but a $40 used ECU off ebay fixed the problem , 6 months later.. :mad:

 

It's the same everything, if i keep on reving the engine it will stay running. I have not tried unpluging MAF or spray any starter fluid yet. On the starter fluid what i'm i looking for or suppose to see or hear>

 

Indy510, sorry to pull you into this, but i'm starting to hate this. All i want is to drive this thing around. but yeah i should of left everything alone..lol.

 

Try just running the iacv from intake and letting the breather on the valve cover just vent

 

Q-tip, i will try that when i get home.

 

I've search here over and over hoping i'll find a fix, but yet nothing. i really want to understand this whole KA error. I'm in central, CA and is ready for a local expert to come and lend a helping hand over some beers.... :thumbup:

[q-tip]

I think when I had mine hooked up the way you do I had the same problem, its a pressure thing. With the engine venting to the iacv directly its too much pressure for it to idle.

[q-tip]

Did it work?

[BluDimer]

Did it work?

 

It works better with the vavle cover vent disconnected from the intake and with just having the iacv connected to the intake.

 

Just like Indy510 if i disconnect the MAF is running all day but not good, because not a right air fuel mixture.

 

I've even spray starting fluid around the intake side and didn't notice any changes.

 

my knock sensor, maf, O2, igniton coil is all connected.

[q-tip]

Is the ecu recently reset or new for the engine? If so it might just need to learn. Let it run for a little bit and see if it gets better

[BluDimer]

Is the ecu recently reset or new for the engine? If so it might just need to learn. Let it run for a little bit and see if it gets better

 

The ECU is has not been reset and is the same. The only differences is that the ECU is not mount it's just sitting on the floor pan. I'll try to do what you suggest when i get home or a chance to. i'll update asap as i do want to get this car back on the road asap. Thanks ...

[q-tip]

With the lines routed the way they are now, it will run thru the rpm range just not idle well?

[BluDimer]

With the lines routed the way they are now, it will run thru the rpm range just not idle well?

 

Yes, running it the way you're telling me to do so is running through the rpm. It's just not idling to well.

 

I have not done anything yet. How long should i let the engine run until the computer recongnize the change and if i have to reset how do i do so safely?

[q-tip]

The iacv idle screw might just need to be adjusted as well. I would let it run for a good 15 minutes at least

[BluDimer]

The iacv idle screw might just need to be adjusted as well. I would let it run for a good 15 minutes at least

 

Q-tip, i have been busy and have not attend to the 510,  but i will report ASAP. Just been doing more researching instead of diving into it. Do you think it could be any of my iacv or tps? i'm thinking about routing my pcv to the intake and see if it helps. Right now i just have the pcv vent to atmosphere.

[banzai510(hainz)]

PM ICEHOUSE on here. he will know

[BluDimer]

PM ICEHOUSE on here. he will know

 

i'm so desperate for any help i did PM Icehouse and Creepycrusier, but i know they are very busy and probably tire of some of our KA nitemares...lol. i need to get this 510 back on the road. The 510 is just teasing me now..it starts but can't run right...Banzai...Thanks. 

[q-tip]

The idle screw on the iacv probably need to be adjusted if it just won't idle but run other wise

[BluDimer]

q-tip, I have not attemp anything yet, will keep post soon.

[Boaty]

My guess is that if it starts up, idles for a moment, and then suddenly dies - unmetered air. Especially so if it sputters for a few. It would make sense... make sure your IACV intake is taking METERED air not UNMETERED air. Meaning it MUST suck air from behind the MAF, not in front of it from atmosphere.

Running the valve cover vent to atmosphere TECHNICALLY means it sucks unmetered air as well, albeit the effects are minimal in comparison to a vacuum leak.

FWIW, I found a massive vacuum leak on my intake manifold, where the brake booster plug was inserted - it was over tightened and caused a crack from the boss. I ended up using JB weld and it has held perfectly fine since the repair.

The mess of vacuum lines under the manifold can also be a source of vacuum leak.

To be thorough, you should check voltage to and from the MAF as dictated in the factory service manual. You'll know if you're getting a bad reading. Mine was personally pegging 12V, which literally means 3.5x the max voltage because of a trace being burned in the ECM. I soldered it back together and it has run well ever since. You'd have to look up the correct voltages @ idle, IGN on, engine off, and engine running. You will (should, at least) check throttle position sensor as well. There is a voltage, earth ground continuity, and resistance test. The resistance test is variable and only gives a range. If it's out of spec, adjust the TPS. This is also required to approrpiately set ignition timing.

And on a completely different note, my girlfriend says you drew a penis in your picture.

 

Once you know for sure your wiring is correct, then you can start ruling out bad parts.

And BTW, the fuel pump turning on and then turning off, is normal operation. The fuel pump primes, and the ECM turns it off until it senses the start signal, and then operates the fuel pump until the engine ceases operation, and then cuts off again. If it is running constantly with the IGN on, engine off - then you have it wired incorrectly. Just FYI. MY set back when first getting my KA going was that I didn't know the distributor had to have power while cranking, and mistakenly hooked the switched 12V side of the harness to IGN ON only, and was unaware it had to be set to IGN START + IGN ON, because as soon as I started cranking her over, the dizzy would lose power. :(

[BluDimer]

My guess is that if it starts up, idles for a moment, and then suddenly dies - unmetered air. Especially so if it sputters for a few. It would make sense... make sure your IACV intake is taking METERED air not UNMETERED air. Meaning it MUST suck air from behind the MAF, not in front of it from atmosphere.

 

Running the valve cover vent to atmosphere TECHNICALLY means it sucks unmetered air as well, albeit the effects are minimal in comparison to a vacuum leak.

 

FWIW, I found a massive vacuum leak on my intake manifold, where the brake booster plug was inserted - it was over tightened and caused a crack from the boss. I ended up using JB weld and it has held perfectly fine since the repair.

 

The mess of vacuum lines under the manifold can also be a source of vacuum leak.

 

To be thorough, you should check voltage to and from the MAF as dictated in the factory service manual. You'll know if you're getting a bad reading. Mine was personally pegging 12V, which literally means 3.5x the max voltage because of a trace being burned in the ECM. I soldered it back together and it has run well ever since. You'd have to look up the correct voltages @ idle, IGN on, engine off, and engine running. You will (should, at least) check throttle position sensor as well. There is a voltage, earth ground continuity, and resistance test. The resistance test is variable and only gives a range. If it's out of spec, adjust the TPS. This is also required to approrpiately set ignition timing.

 

And on a completely different note, my girlfriend says you drew a penis in your picture.

 

 

Once you know for sure your wiring is correct, then you can start ruling out bad parts.

 

And BTW, the fuel pump turning on and then turning off, is normal operation. The fuel pump primes, and the ECM turns it off until it senses the start signal, and then operates the fuel pump until the engine ceases operation, and then cuts off again. If it is running constantly with the IGN on, engine off - then you have it wired incorrectly. Just FYI. MY set back when first getting my KA going was that I didn't know the distributor had to have power while cranking, and mistakenly hooked the switched 12V side of the harness to IGN ON only, and was unaware it had to be set to IGN START + IGN ON, because as soon as I started cranking her over, the dizzy would lose power. :(

 

First off sorry about the drawing..lol.

 

I will check my manifolds very carefully again, i block the egr off..i will check my pcv plugs..and any nuts and bolts.

 

I was planning on connecting the pcv vent with a T adaptor and connect to the brake booster and the tube on the back of the intake..

 

As for my icav i don't have the brown n silver dot connected is was cut.

 

things i'm not sure of are:

 

how to check my MAF voltage..check  or adjust tps and the timing as to how much.. 

 

i'm will report my finding as soon as i get some more courage....i'm just still hating it...

 

Thanks..

[Boaty]

http://www.nicoclub.com/FSM/240sx/91-94/

That link just became your new best friend.

The MAF voltage, be careful. You don't want to short anything out. It'll tell you the correct pins to probe and everything. Be extra careful not to damage the wires, the plug, or the protective rubber boot. It's there for a reason, because the signal from the MAF is extremely sensitive - and resistance will completely throw it off. Consider it the most fragile, picky, and unfortunately - expensive parts on your KA swap, and treat it like it's made of fine china.

The TPS is located on the side of the throttle body. Once again the FSM will show you exactly how to diagnose, and adjust it. I could never get my fatty ass fingers far enough in there with a wrench to actually loosen the adjustment bolts on the TPS, so I ended up winging it with pliers. It only has to be snug, never tight, after it's set correctly. The adjustment has a range, in which you should start in the middle of, and fine tune it up or down to find that sweet spot. FWIW, mine runs a little better on the low side, but dumps fuel hard at WOT (which is normal, being honest). If I go to the opposite side of the spectrum I have an odd flat-spot at WOT while accelerating and it sputters wierd. I set it where it's at right now, and forgot about it entirely. It pissed me off.

 

On the IACV, I'm not sure what you mean by brown and silver - the S13 has a light blue connector, and S14's have a purple connector (and the male/female is reversed). The mid engine harness can be swapped between S13/S14 to provide you with the correct harness plugs to whatever IACV you have. I don't think this is really your issue, but it's EFI and almost everything can have an effect on another component. If everything is working as it should, then you can start breaking the problem down to mechanical issues vs. electrical issues.

Having your engine and chassis grounded sufficiently will help weed out some issues as well. A clean +12V helps as well, but it has to go somewhere. Electrons flow. Therefore your front door has to be as good as your back door, giggity.

 

The timing will also be outlined in the FSM.
You disconnect the TPS, adjust your idle, and then set your timing. In my instance, I can never get the idle low enough because (I BELIEVE) I have a bad AAC diaphragm (the air regulator you can only get from Nissan and is expensive and a supreme BITCH to get to without ripping the intake off). But, if you can get it to idle correctly, you can then set your timing (and vice versa). I believe it's +20 degrees. If the TPS is connected, the timing will vary because it's being controlled by the TPS and other sensors, where as with it disconnected it runs without adjustment to set your static timing at the distributor (which is dubbed the CAS - crank angle sensor by the Nissan FSM).

 

Hope this helps. Reading the FSM will give you a better idea what is going on.