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 last night (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 plugs - 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. Any ideas what would cause this. My battery is in the trunk and water is leaking onto the ground to the chassis so next thought is to try to dry it out and then grind it down and reattach and paint over if that might be the cause. I've never seen this engine do anything odd before that swapping fuel injectors didn't fix so I'm kinda lost. Doesn't seem like leakage because there is just black smoke from running rich coming out the back occasionally but not consistently. Maybe spark plugs - I'm going to try and pull them tomorrow to better diagnose the engine condition? Any other suggestions?

[rocksteady_racer]

Ok - so it's pretty dry and still not running right - since the ground in the trunk seems to have rusted I bought a 2 gauge wire to replace it with (I run 0 gauge to the hood). Also I got a new set of spark plug wires since inside they were tatty and got aa new set of sparks. I'll teell you if that fixes it. If not I'm lost - the only other thing I can think of is the tps gave out (have to check with my multimeter.

[Spring Break '92]

You're on the right track, but it is better to diagnose the problem correctly and pinpoint the root cause of the issue before you throw parts at it. Even if you replace the plugs/wires, you still could have a bad distributor, coil, cap, rotor, any sensor or wiring for said sensor, etc. The problem you are describing is so vast in possibilities that there is no one answer to point you in the right direction.

[rocksteady_racer]

Ok I swapped plugs and wires - and repaired the ground. Still running the same. After reviewing the plugs all cylinders are running good albeit a little lean except cylinder 4 which is running excessively rich. What could cause that? The intake manifold gasket maybe? Now I'm just confused lol. Any help would be greatly appreciated.

[aznpoopy]

main 2 culprits

either fuel is dumping in (injector stuck open electrically, mechanically, or the o-ring is torn and fuel is leaking past)

or the fuel is not being burned, flooding the cylinder (spark plug not firing b/c spark plug bad, spark plug not receiving signal, etc.)

[rocksteady_racer]

As to Spring Break's Response:
I was just replacing the stuff I know I haven't replaced on this car since I bought it so far. 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 coil to try if that doesn't work but I'm still leaning toward the injector harness itself. 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 inidcation - if it's not the pigtail or distributor I guess I'll start checking every sensor with my multimeter.


As to Aznpoopy's response:
Hmmm I know the spark plug is good since I just replaced it and it's getting spark (the udder itself sparking). I just swapped the injector out with one I knew worked so it can't be the injector itself - so I'm guessing the pig tail connector then right? The only way to test the injector pigtail itself is to use a noid light right? If it is the connector. where can I get a new one to replace it?

[aznpoopy]

you don't need to manhandle the harness plug, just test it with a multimeter according to the FSM.

you sure you are installing the injectors properly? o-rings tear stupid easy on install.

[rocksteady_racer]

Yea I know. I've had that problem a ridiculous amount of times on my ka24e. I use petroleum jelly to slide them in to make sure they don't tear and it's worked on both my engines all the time's i've used it.

[rocksteady_racer]

Ok I looked through the fsm and can't find anywhere what the injector harness should be reading. I did however check all my injectors and they are all running at 11 ohms so they are all good. Anybody, know what the injector harness should be reading? If the connector's broken it should be running consistently rather than pulsing right?

[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.

[rocksteady_racer]

Compression test Results
Cylinder #1 190
Cylinder #2 190
Cylinder #3 190
Cylinder #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.

I guess I'll have to pull the rail and see if all the injector's are spraying properly? 4th cylinder is getting spark and I replaced the rotor in the distributor which seemed to smooth out the engine but did not fix the root cause of the problem. So the only thing I could think of is either the injector pigtail in 4th somehow got damaged - because I swapped injectors with a known working one so I know it's not the injector itself - or maybe the ecu pin came loose which I highly doubt but I guess it's better to check than assume in the negatory.

[rocksteady_racer]

BUMP

Anyone got any more suggestions for this repair? I'm kind of stumped at this point besides it being the injector pigtail or ecu connector?

[rocksteady_racer]

Gah I'm stupid lol things to check when your engine isn't running right:

The ECU and Connector LoL

Somehow rain water got in there and corroded 5 pins - that's why it was running but barely. So I swapped mine out with my other ecu and cleaned up the connector best I could - tiny freakin spaces to clean out.

[PoorMans180SX]

Thanks for posting up the solution!

[aznpoopy]

glad you figured it out man.

[rocksteady_racer]

Now to figure out why my car is leaking everywhere!!! LoL The trunk lid is leaking like at the bottom right corner (which I assume is because I need a new seal around the glass like my windshield) and the door seals are leaking at the exact point on both side at the top lol. Silicone everything!!