S13 KA24DE Engine Help Please

[rocksteady_racer]

Ok my ka24de was running perfect for the last 5 months. It just rained here in phila pretty hard two days ago (don't know if this is a consequence of that or just a coincidence). Anyway I took a 5 block drive over to my local convenience store and came home yesterday - ran perfect the whole way. Now today I started it up and it seems to be running on 3 cylinders or under massive retard. I checked by pulling the plug wires - I pulled cylinder 1's spark plug boot and the engine stalled. I pulled cylinder 2's spark plug boot and it stalled again. I thought ok that's weird. 3's boot wouldn't come out for some reason and i didn't want to yank it too hard so it could be a problem there. I pulled cylinder 4 and it ran the same as it did with it in there. So I was like, I'll just swap the fuel injector in cylinder 4 hoping that would change something (I have 5 extras that I know work). Anyway so I swapped it and no change.

So then today I swapped the plugs with a new set and new wires since inside they were tatty. All the cylinders were running a little lean but still pretty fair except cylinder 4 which is running excessively rich. I've never seen this engine do anything odd before that swapping fuel injectors didn't fix so I'm kinda lost.

At this point I'm going to pull the rotor cap and see if the rotor or connectors underneath are damaged to make sure 4 is getting the right amount of spark. And I have another ignition coil that I know is good to try if that doesn't work but I'm still leaning toward the injector #4's harness itself. The only way to check an injector pig tail connector is with a noid light right? The engine's not throwing a light but to be honest none of my 240's every throw a light or code so that's no indication - if it's not the pigtail or distributor I guess I'll start checking every sensor with my multimeter. Any other suggestions? I'm kind of confused at this point any body else ever have a similar problem? Only cylinder 4 is running rich.

[sx moneypit]

If the number 4 cylinder is running rich then injector must be spraying fuel. Sounds like you have an ignition or some other problem. You might want to check the compression.

[rocksteady_racer]

I swapped the distributor rotor and now it's running different but I wouldn't say fixed. Do you think maybe it fouled the 02 sensor or the computer just should be reset and it'll fix itself? Or might it be the CAS in the distributor? On the KA24DE can I buy that part separate or do I have to buy a whole new dis?

Because recently before the 4th cylinder rich problem the idle has been erratic and ever since 4th has been running rich it seems to idle ludicrously low compared to the 700 it was before (now it's idling at 450-500) and it'll bounce back and forth then sometimes if I stop to fast the car will just stall out.

I'm going to run a compression test tomorrow see if that sheds any light but if that turns out negative the only 2 things I could think of are the distributor CAS or the injector plug (I got 6 extras that I remembered I had from my 96 Maxima harness. So we'll see I guess.
Modified by rocksteady_racer at 2:08 PM 3/25/2010

[sx moneypit]

I don't think the problem is with the distributor. On every Nissan i have dealt with when the CAS fails the car will not start. Pull the fuel rail off and have some one crank the car and see what your spray pattern looks like out of the injectors.

[rocksteady_racer]

Ok thanks that helps a little alot . I'll pull the rail tomorrow when it's not raining and run a compression test (separately of course). God I hate philly rain spells lol.

[sx moneypit]

Sounds good, keep us posted.

[rocksteady_racer]

Ok it's not raining now so I'm going to pick up my mom then run a comp test. Before I run the comp test, I just disconnect the ignition coil and release the fuel pressure and disable the fuel pump right? I know I leave the spark plugs in and remove them and check the cylinder and put it back so it's accurate. When you are running the test, you have to have the throttle at wide open so the numbers are accurate right? Sorry if these are stupid questions but I haven't done a comp test in forever lol. And last time I did something wrong with my ka24e because I was getting 130 across the board (I think because I didn't have the pedal open all the way).

[sx moneypit]

You are on the right track.

[rocksteady_racer]

Compression test ResultsCylinder #1 190Cylinder #2 190Cylinder #3 190Cylinder #4 190

So what else could it be? My numbers might be a little off but it was about around there 185-195 my gauge is a little confusing to read.

[sx moneypit]

Those numbers look good.Get your fuel rail off and check your spray pattern and check for spark on your #4 plug. I will check this thread in the morning.

[rocksteady_racer]

I know there is spark going to cylinder 4 -am I sure it's the right amount of spark at the right time ::. and I just put that injector in (I know it works it came from my other engine that blew lol but seriously positive it works) . So my only two guesses left are the connector at the ecu wiggled free on it's own or the pigtail connector broke somehow right? I got a bunch of connectors in my garage I can source off my 96 maxima (thank god I didn't junk it yet lol). What else could it be? But I will double check the flow tomorrow since I got stuff to do today. That should also tell me if the connector is dumping instead of flowing properly right? And thanks money pit - everyone on zilvia just kind of ignored my question - it's not like I haven't patched engines before - it's just that this one is an enigma at this point lol

EDIT: And another odd turn of events. The rpm has stabilized at 700 but it's still idling rough but at a steady rpm -weird?
Modified by rocksteady_racer at 10:29 AM 3/27/2010

[sx moneypit]

If the injector connector is bad it will cause a missfire but it is not going to cause the injector to dump excessive fuel. Since you don't have a noid light to check the injector pulse,you can take a screwdriver with a long blade on it, put the blade end on the injector, put your ear on the other end and listen to the injector .If it is clicking, most likely it is working.I will check this thread Monday morning .Good luck!

[rocksteady_racer]

OK I gotcha - now this may sound weird - but I did the injector test.And the first injector was pulsing and so were the other 3. But the pulses coming from the other injectors seemed alot fainter - that's the only way to put it. the first cylinder's injector was pulsing really hard and the other 3 were pulsing kinda softly. But they all are pulsing. You think maybe I should just try to ground the motor at a different spot and that has been causing the problem the whole time - a bad engine ground amplified by the rain or try the other ecu I have (same car different year(93 - same drive train auto)).

It's good I didn't run out and sell my extra parts lol.

[Kouki4Zenki]

My car is doing almost the same exact thing from cyl number 4. Im thinking its a grounding problem too cuz when i pulled the dipstick for the oil, the idle went up higher and seemed more stable. When i pulled the stick out, it'll drop rpms and stumble down even more...making me believe maybe the engines trying to ground itself and is not getting enough?

Lets find an answer to this!!!

[sx moneypit]

If the injector doesn't have a nice solid click it is usually a sign that it is bad or dirty. A bad ground can cause all sorts of headaches, you definitely need to check that.

[rocksteady_racer]

And I did find an answer!!! MWAHAHAHAHAHHA!!!Nah just kidding about the evil laugh....But what was causing mine - running excessively rich on one cylinder, running slightly lean on the others, and also causing a mean amount of heat from the engine (also odd because my dohc usually runs really cool) was.....The ECU connector got some rain water in it and had corroded on like 5 pins - so I put my other ecu in there (still haven't figured out how to get the corrosion out of the connector itself). And now it runs like she is brand new again. YAY - slideways . And I got my 5 speed today so hopefully soon I'll do my swap.

[rocksteady_racer]

But I'm still going to reground the motor because my sohc was just plain nicer after I ran a new ground cable from the block (the intake manifold connector is usually the culprit) to two solid grounds instead of one. And after I grind the metal down and hook up a couple new grounds to bare metal I like to paint over top to prevent corrosion.
Modified by rocksteady_racer at 9:15 AM 3/30/2010

[sx moneypit]

Glad you got it figured out.Get you some electrical contact cleaner for your ECU connector and after you clean it put some dielectric grease on it to keep the moisture out.

[rocksteady_racer]

You know what's funny - I should have thought of that first. My uncle has a 93 mark viii with a similiar problem - idling rough etc and it was because the maf connector had gotten water in it somehow and corroded.

[sx moneypit]

I think i would find out where the water is coming from so you don't have any more problems .

[rocksteady_racer]

I know where it's coming from lol - how to keep it out without spending an arm and a leg another story - the windows roll up to a rubber piece in the s13s you know (no frame) - so over time this car especially compared to my 90, the rubber has started to fall apart. I guess the affordable thing to do would be to fill the rubber with silicon since nissan wants an arm and a leg for trim pieces. Also my trunk is leaking in the oddest spot (like underneath the bottom right underside of the trunk deck - so I assume I should get the glass resealed right if it's not actually leaking from the sides like I originally thought and I gotta get my windshield resealed - old cars lol. But it hasn't stop raining long enough for me to do anything - this weather is ridiculous
Modified by rocksteady_racer at 11:13 AM 3/31/2010

[lastchancelarry]

try looking at the little O ring on the bottom of the injector that is an ongiong probem for me........

[nigel34]

I second last chance... just replaced my #4 injector seals yesterday and fixed all the symptoms you guys just had. The seal didnt even look torn, but after running the car and pulling the #4 plug, it was wet. changed seals and my idle went back to 700ish and runs smooth.