KA-24DE Missing/Retarded Timing

[bcar240]

Hi again all,My original post is here zerothread/271875

But I’ll summarize that thread:-Car feels like it is missing or timing is being retarded at certain rpm ranges (1000-1500 and just before 2500). Painfully obvious loss of power and change in exhaust note during this.-Problem gets worse as engine heats up and with headlights/brakes/steering inputs (additional draws on engine). After a long drive (thorough heatsoaking), the problem is very bad, sometimes car can barely stay running and has died more than a few times.-After clutching from cruising rpms, idle bounces a few times between 700 and 200-300 before settling in around 700.-Engine vibrates horribly at warm-up idle (although this could just be engine mounts)

What I’ve done:-changed plug wires and plugs again-changed knock sensor (seemed to me to make a slight improvement)

Any thoughts on what it could be or what to check next? I’ll answer any questions about it to the best of my ability. Thanks in advance!

[DroptopDrifting]

i had almost the same problem and it was a mix of 2 things for me. my TPS needed to be replaced, and my timing chain guide (the little plastic one) was broken and the chain was off a little, which caused major timing retard and loss of power. you can get the guide for cheap seperately, but i recommend a full timing rebuild, its 330 + s/h from AMSPerformance or from Auto Parts Warehouse its 270 s/h is free plus it comes with all cam sprockets and ****. the tps you can get anywhere at about the same price of like $40

oh and with any timing rebuild kit, make sure to get the cover o-ring, it doesnt come with the kit but its like $6 from autopartswarehouse.

anyway, gl

p.s. dont forget to check for vaccuum leaks, pick up some starter fluid...

[niceguy]

Sounds like a possible distributor problem....2 things can happen. 1, oil can leak into the dist causing the misfire which worsens over time, or in my case, the internal diode (or CAS basically) in the distributor would short intermittantly once it started to heat up w/engine temp,etc...

Check your ignition system (wires/cap/etc)...I've also had EGR issues and MAF connections(MAF symptoms usually including VERY rich condition, gas smell, black exhaust) cause very similar problems so it's hard to say and can get expensive w/o doing some troubleshooting of your own. Some shops will just throw parts at it until they give up, make you broke or finally solve the problem...

[bcar240]

Good, good! Some more things to add to my list to check!

I was wondering about the TPS before, if I try to rev the engine up a little at idle, I am having to fight something that is continually trying to adjust it back to idle speed. I had never noticed that previously, so I thought it might be the TPS acting funny. I don't *think* the timing chain is the problem, or hope it's not anyway (fingers crossed). Once I get it above 2500rpm is runs perfectly fine.

The current cap and rotor are about 1.5 years old now, I will probably replace those next. I was also concerned about the distributor before. Whatever it is, it is something that is affected by both heat and possibly vibrations (some bad harmonics or something that makes the problem surface at certain rpms). At the moment, the car is actually getting very good mileage, 24-27, so that was leading me to think that whatever is messing up is not permanent, only happening during those periods. I'm not sure what, if anything, this would rule out though. My cat is pretty well shot right now and there is a hole in the exhaust ahead of the muffler so I get all sorts of interesting smells, but I'm pretty sure I've noticed a fuel-rich scent at times.

Btw, speaking of MAFS is a KA-E MAFS compatable with a DE? I have one of those in my shed.

[DroptopDrifting]

for the way it rev's and the symptoms you're feeling, i had exactly the same symptoms. my timing chain guide was broken. it's plastic. it's common. if you dont wanna replace everything, the guide is really cheap, you can get it from any Advance Auto Parts stores. as for the misfire, i forgot to mention that. my check engine light used to come on at high revs, but go away when it shifted. i assumed misfire at high rpms, just like yours. i happened to have an msd SCI-L ignition laying around so i bought a blaster 2 coil pack and hooked up the new ignition, misfire is gone, no more check engine light. so yeah, it was a distributor problem with mine. its funny, those were always my 2 major issues and i thought i was alone, but it seems its more common than i thought. i also thought it was my plugs/wires/cap/rotor/clogged cat. i got all new plugs/wires/rotor/cap and gutted the cat and i noticed a lil bit difference (in a good way) but what really fixed those problems is the ignition and timing chain guide. the timing chain guide goes if you dont change your oil within 3k miles, i used to change it like every 5k miles and this is the result of that. or so im told and it sounds reasonable.... as for the ignition, i never bothered to figure out what happened with the distributor, but the new ignition fixed it right up.

anyway, good luck with it.

[bcar240]

sorry for neglecting my own thread, Was out of town for the weekend.

I appreciate that info. When you say misfire at high-rpms, what are you considering high? Mine mis-fires until around 2500, then it suddenly vanishes and the car runs fine over that. I'm not ruling the timing chain out just yet, but some testing over the last couple days is making me lean towards TPS (seems to not do well in 15%~60% pedal press). I really can't explain it logically, but just from experience this seems like an electrical/sensor problem to me. While trying to avoid the mentioned "throwing parts at it" solution, I figured I'd go ahead and rule out some of the less expensive stuff. Thanks!

[DroptopDrifting]

oh yeah. definately check the TPS first. like i said, that was part of my problem also. anyway, let me know when you figure it out, it's got me curious

[240_fun]

heyy sry to bring back an old thread but ive been having the same issue for a long time my ka-de misses at 2500 almost all the time. my car also seems like it losses of power after that (tps bad = too lean at high rpms?). plus sometimes after i shift it does the same thing, no power then all of a sudden it shudders like crazy nd i have some power back. soo i was kinda thinking the tps sensor but maybe the distributor? ne help would be fine and greatly appreciated.

[bcar240]

hey again. Sorry I missed your post, but I just figure out what was wrong with my car.

Problem ended up being a combination of knock sensor, which I replaced and improved some of the more random problems, and failing fuel injectors. The fuel injectors on cylinder 1 and 4 were not fully actuating in certain conditions and leaning out the cylinders (which explains why my fuel consumption didn't plummet.) They were both acting up sporatically and working fine at other times which made diagnosing hard. #1 was worse, so I noticed that first and replaced it so now it's acting better and I've noticed #4 acting up too and will replace it as well.

I think this is all that was wrong, we will find out shortly.