Hello - first time poster and new Acty SDX owner. Was hoping I could get some tips for a frustrating issue I’ve been experiencing since I got the truck one month ago. As the title mentions, my 1995 Acty stalls when it warms up. Seems to run fine for 10-15 mins then it’s idle gets really rough and it stalls frequently. When trying to drive it after it warms it “bucks”’and loses power and ultimately will stall once the RPMs get low enough. Has a tough time restarting until it gets cool again. I contacted the place I bought it from in Japan and they were certain it was the carburetor, specifically the air shut off solenoid. They sent me an entire new carb assembly for free and I had the local mechanic install it and it’s still doing the same exact thing it was doing before! More back and forth with Mitsui and they are saying it’s because I haven’t bled the coolant enough from the bleeders on the top of the engine. I keep bleeding, but no difference (although I’m not sure I am performing the bleeding correctly?) additionally, I have replaced plugs, plug wires, air filter, fuel filter, fuel pump - I just can’t figure it out. Something tells me it is still related to the carburetor but am I really that unlucky to have two bad air cutoff solenoids? I have checked the power coming in at the valve and it’s giving a constant 14V, is that what it is supposed to do or should it fluctuate depending on if it’s getting the signal to engage the solenoid or not? If I unplug the solenoid power when it’s running cold there is no difference, the Acty still runs fine. When it’s warm and I unplug it, it doesn’t really change the way it runs either although it’s just running horrible at that point anyway. Frustrating!!!
Have you checked what kind of spark you have when it starts to act up? Kind of sounds like you have a coil well on its way to failure. Fred
Could be? But I don’t understand why it would only start after being warmed. From my understanding, the choke on these shuts off once the engine hits a certain temp. That is when it seems I am running into issues. another thing to note, the exhaust temp sensor light is illuminated. I am not sure if this is related or if like with some others the guts of the cats gave out and are creating a blockage in the exhaust.
was the carb they sent you a new carb with new solenoids? is it going into high idle when starting then dropping to normal idle when it warms?
Check your charcoal canister. It its blocked then it will cause issues with fuel flow on most cars. It can increase the fuel pressure to the point of flooding the carb. What do you plugs look like when this happens? Dry, wet, burnt?
I don’t suspect the charcoal canister because we have it completely bypassed and it does the same thing.
Seems like you replaced the most com issue. -Have you replaced the cap and rotor? -replaced fuel filter? - since you do have that cat light, it’s telling you it’s overheating. I seriously replace it or cut it out
Having a similar issue with my '95 Acty that I also purchased from Mitsui. I've changed the fuel filter and air filter. I haven't had a chance to check my plugs/distributor cap/carb yet (the truck is currently getting painted). My issue started a few weeks after I got the truck home. It starts right up with no issues, after taking it into town which is about a 15 min drive it has trouble starting and I have to let the engine crank while giving it gas. After finally getting it started it does seem to buck a bit at lower rpms and wants to die when idling at a stop light. @natenewthread let me know if you ever get your issues figured out.
usually easy fixes for this are -check your idle it might be too low , you might have to bump it up -the rotor(in the cap) gets worn out and when it gets warm it makes a bad connection -dirty negative cable -pull your fuses and make sure(wire brush) any of them that look corroded
Thanks, I’ll try some of these this weekend. The fuses I have never even looked at so I’ll start there. We inspected the rotor cap and it was brand new. the oddest thing is that it only occurs after warmup. Some of the things you listed seem like they’d be happening immediately if they were in fact the issue.
Did you figure out the cause of you problem? my truck started having similar symptoms the other day when taking it down the street, after it warmed up seemed to have the stuttering/idle issue till it completely cools down.
Sorry to pull up an old post but @natenewthread were you able to figure out the issue? I'm having the same problem on my 91 Acty truck.
Yep. It’s fixed, the issue was a $28 part that is held onto the side of the distributor by two screws - it’s called the distributor igniter or “ignition module”. I don’t know exactly why this part failing causes this issue sometimes, but it does and must be something to do with the contacts become less effective once they heat. Also, please be aware that several other things can cause this issue including the air vent solenoid on the carb or other carb related issues tied to fuel leanness. But this part may be worth ordering and swapping since it’s so cheap and easily accessible. good luck!
Thanks for the quick response! I've already ordered the part and can't wait to give it a shot. I've cleaned the carb, changed the solenoids, found out the alternator wasn't working and replaced that, changed the fuel filter, and a few other things. Still having this issue and I'm getting a little frustrated. Really like the truck but if it doesn't run well I can't do much with it. Hopeful this is the solution. Also, have a tuneup kit on the way which can't hurt... thanks again.
No luck. I replaced the ignition module, put in new spark plugs and wires, and replaced the distributor cap and rotor. It runs until its warmed up then I have to keep feathering the throttle to keep it running. It will drive just fine but stop at a stop sign and its not easy to keep it going. open to any other ideas.
Could it just be a simple adjustment of the idle screw so that after the fast idle stops after the initial start, the normal idle is at a slightly higher RPM? With the issue I had (that the ignition module fixed), I couldn’t accelerate after the car warmed. It actually wouldn’t start and if it did start when I was giving it gas it could completely lose all power. Your sounds more like an adjustment to the carb or the leanness of the air/fuel after it warms up.
I believe you are on the right track and there's also an issue with the choke. I don't think it's adjusting properly when the truck is warm. I was able to turn the choke and it would stay running. Time for a mechanic to wrap this thing up!
Was reading through this thread for understanding, and thought I'd share a bit of my experience/observation: the coil and I believe condenser are mounted above the catalytic converter. There's the aux cooling fan that seems to be there to keep them from melting, but in general ignition coils don't do well in heat... In my case, the cable holder for the condenser apparently came loose from it's clip and was resting on the exhaust heat shield, and partially melted through. Does anyone know offhand what turns on the aux cooling fan? Is it the thermo switch post-cat? Mine is hanging on by a literal wire thread...
cooling fan: this thread helps https://minitrucktalk.com/threads/cooling-fan-after-shutoff-disable.15406/#post-89087
Hi folks, Experiencing similar issues with my truck. Starts up fine, if parked (to just warm up) it doesn't die out, the moment I try I take it out and try to take a corner, or try to move after stopping in drive (at like a stop sign), I stall, but am able to start up right away [it sounds a lot like Nate's original issue so I'm very optimistic!]. I have the ICM of a ʻ85 Prelude (autozone had an online one for $65), problem for me is because I have AC to reach in and try to get those screws out is next to impossible. Any tips?
