S13 KA24DE MAF problems

[INDY510]

My S13 KA24DE will not run for more than 4 seconds.....

 

My commute happens to be longer than that .. :(

 

 

The car starts normally and will even rev up to 3K rpm , and stay there for 4 seconds,,, but no matter what rpm it cuts out after 4 seconds.

 

It feels like something is telling the motor to cut fuel and spark,,,, because even if I step on the gas pedal it just dies without any hope of running.

 

The wierd part: it runs and idles fine if the MAF is unplugged........ it will idle all day with the MAF unplugged

 

 

Anyone ever have this problem? ... . I have been searching the various nissan forums and I have tried:

--New gasket for the throttle body,,,, cleaned the MAF,,,, checked the wires at the MAF plug, and the throttle body plugs

--Checked for vacuum leaks,,, tried various IACV and valve cover breather configurations

--Un-hooked the battery,,, and unplugged the ECU ,,,,,, checked the fuel pump and relay,,,, checked all the fuel line plugs and wires

--Checked all the dizzy wires and coil wires,,,,,, tried running it without a air filter, and different length cold air intake pipes

 

 

And after two days,,,, the motor still will not run for more than 4 seconds,, , unless I unplug the MAF

 

So can I take my ECU to a shop and have it scanned? ... will I get in trouble if it has NO smog equipment, no 02 sensor for 5k miles, EGR block off plate, and tons of missing sensors?

 

Or maybe Nismo Dr. knows why the MAF would tell the motor to shut off? .... but it runs and idles without the MAF.... .. . and dies immediately if I plug in the MAF while it's running

 

 

I have tried everything,,,,, and it was running good like this for two months:

 

 

The IACV tube is hooked up,,, and I tried running a Tee to the valve cover breather too...... nothing has helped

 

The MAF still has the two very small wires intact and I even tried spraying some carb cleaner on them....

 

 

Why would the car run good for two months and then just die? .... bad MAF? bad ECU? bad connection on one of the many plugs?

 

I give up..... . . . anyone have some dual carbs for a KA24DE........ . . or better yet: , A idea of how I can fix this problem?

 

Please help......... :(

[thisismatt]

Vacuum leak. Run it without the maf and spray around the intake with starter fluid or a propane torch (not lit).

[napz510]

install a fuel gauge and check fuel pressure. Check the ecu code by doing manually..

[sssr20det510]

I would try a new maf

[thisismatt]

I would try a new maf

I would try the free, or close to free, alternatives first :) I've heard of the exact same problem before, and it wasn't solved by changing the MAF. After looking at INDY's other threads on this car/motor, I really wouldn't be surprised if it was a simple vacuum leak issue.

[INDY510]

I tried the propane torch...... nothing

 

I tried plugging the brake booster hose......... nothing

 

Cleaned all the wires to the fuel pump........ nothing

 

 

All the small vacuum lines are still how they were for the last two months of driving...... and the brake booster vacuum line is plugged and not leaking.....

 

 

Could there be some giant crack in the intake manifold where the propane torch can't reach?

 

 

 

It really feels like everything is running normally and revs normally....... but only for 4 seconds

 

 

Something is telling the motor to turn off....... because it cuts out so fast..... there is no sputter, or miss,,,, it just turns off after 4 seconds.

 

 

Please help........ I have tried every vacuum line......... the fuel pump is definatley working........ any other suggestions???

[INDY510]

Is it worth un-wrapping all the wires that go to the MAF?

 

 

And maybe the plugs that go to the throttle body?

 

I would try a new maf

 

I just called the Nissan parts counter.......... a new MAF is $575.20 .... . :huh:

 

 

No Thanks

[banzai510(hainz)]

PM Icehouse !!!!!!!!

he knows these systems.

 

Thats why I like L motors and sidrafts!!!!!!!!!!!!!!E Z

[datzenmike]

What about jumpering 12 v to the pump so it can't be shut off by the ecu, see if it keeps running.

[INDY510]

What about jumpering 12 v to the pump so it can't be shut off by the ecu, see if it keeps running.

Damm Mike,,, that "was" a good idea..... .. but it didn't work ...... :(

 

 

I let the fuel pump run for a few seconds........ it started right up...... then died in 4 seconds..... :angry:

 

The fuel pump was still running so I tried it again....... and left it at 3k rpm ........ and it died in 4 seconds....

 

 

WTF???? ..... I agree with Hianz ,, dual carbs are SO much easier...... however I haven't even looked at my 510 since I got this car, because it has been nothing but problems....

 

 

What else can I do? ....... I really don't want to buy some used MAF off ebay for $95 ...... or a new one for $575

 

 

I found some ways to check the signal from the MAF...... it has three wires...... anyone know which is the sender wire?

 

 

I see a few options: (1) spend every free minute trying to fix this problem ... (2) run my dual mikunis on this motor .. (3) Match/can o' gas .. (4) Un-flip the crossmember and put my L18 with dual carbs in with the KA trans .. (4) go deeper into debt and get a SR20DE ... (5) KA24DET ... :D

[datzenmike]

So we have proved that the fuel isn't being shut off by the ECU then.

 

Unplug and plug in the CAS on the dizzy. Maybe a bad connection.

 

Unplug and plug in the throttle position sensor on the throttle body. Maybe a bad connection.

[INDY510]

The S13 KA24DE MAF plug has three wires: black = ground....... blk/wht = 12v ........ white = sender wire

 

 

I found a way to check the sender wire on the internet: I used my multimeter and checked the ground, and the 12v wire with the key ON ........ and the sender wire has a "normal" 0.22 volts....... I tried shaking the MAF and tapping it... and the voltage stayed the same.

 

I lightly blew air thru the MAF and the voltage jumped to 0.89 volts and raised equally depending on the amount of air....

 

The voltage never dropped and seemed very consistent....

 

 

My internet searching leads me to believe this is a normal funtioning MAF........

 

 

 

 

So what now??? ...... it's not fuel ........ it's not the MAF ...... all the dizzy wires are good

 

 

I guess I need to find a vacuum leak???

 

 

If it is not a vacuum leak I think it is a wiring problem....... because I tucked the wiring harness,,,, and it used to look like this:

 

 

I drove it 300 miles after tucking the wiring, but I guess I will pull it out and un-wrap everything

 

 

At least I'm narrowing down what's not wrong with the car ......... hopefully I will be driving again soon ...... :angry:

[Unclejesse88]

looking at your first picture, I would say you have a vacuum leak, caused by the valve cover breather. That is, unless you do not have the pcv hooked up. The maf needs to read ALL the air entering the engine, including the breather/pcv system. It's called a closed system. With a valve cover breather, you have unmetered air that the maf isn't reading, causing the ecu read lean and therefore enrich the mixture. "Usual" maf voltage at idle should be no less than .7 volts. If it is less then you have a vacuum leak.

[Unclejesse88]

BTW, the breather is usually plumbed just ahead of the throttle body.

[INDY510]

I tried running a tee to the valve cover breather off the IACV hose........ and it did run better... .... but it died after 4 seconds....

 

 

 

So most likely: if the MAF is good it is probably a vacuum leak? ........ because it will idle for ever without the MAF plugged in.....

 

 

Can the MAF tell the ECU to shut off spark and fuel after 4 seconds?

[INDY510]

Today's diagnosis: .. Clogged IACV tube???

 

 

Can I spray carb cleaner down the IACV tube?....... or can I take it out for cleaning without removing the whole intake manifold?

 

 

 

I had some extra tubing bends that came with my cold air intake... .. ... so I tried this:

 

 

 

You can see the MAF is plugged in.......... and it ran for more than 4 seconds!!!!!

 

I had to keep the throttle open though,,, because the IACV tube was not connected....

 

 

So what does that mean???? ....

 

 

My next test was to try my old intake with a tee to the valve cover and the IACV tube:

 

 

 

You can see the MAF plugged in........ and it ran great!!! .......... ,, .. but only for 4 seconds

 

 

Ugh.... .. :( ................ ........ :angry:

 

 

So I reached behind the intake manifold and un-plugged the purple plug...... .. I think it is the IACV plug?

 

 

And now the car runs for more than 4 seconds!!!! .....

 

 

So what does that mean???

 

 

How do I clean the IACV tube without taking off the intake manifold???? ......... Or could this still be a vacuum leak?

[Mr.Dean_Yates]

I tried running a tee to the valve cover breather off the IACV hose........ and it did run better... .... but it died after 4 seconds....

 

 

 

So most likely: if the MAF is good it is probably a vacuum leak? ........ because it will idle for ever without the MAF plugged in.....

 

 

Can the MAF tell the ECU to shut off spark and fuel after 4 seconds?

 

 

will a ka run with out a maf? in general not just with mysterious vacuum leak? and if you build a ka24det do you just throw out the maf? cuz thats the plan for my 720

[Farmer Joe]

holy old post batman...

 

indy dont even have that car anymore...