My automatic Hijet S110P truck (EF-ES fuel injection engine) takes three tries to start before it idles smoothly. I crank the key, it struggles to start, idles VERY rough, then stalls out. After the third (sometimes fourth) time cranking the key, it idles fine. I only noticed that this was happening when it was cold outside. When the engine is warm this does not happen; cranks and starts perfectly fine after I drive it to the store and start it again in the parking lot or whatever. Recently cleaned out my throttle body and ISC (idle speed control) valve. They weren't very dirty, but I figured this is the most obvious place to look when you're trying to figure out rough idle issues. Before cleaning (it wasn't even very dirty): Post-cleaning: I followed these instructions to test my ISC valve by hooking up the terminals to a 9v battery: https://www.toyotanation.com/thread...on-the-toyota-idle-air-control-valve.1676205/ Pictures of how to test the ISC valve from the article: The valve opens and closes as described. However, it is about half-open when there is no battery power applied to either terminal. Is this normal? (picture below) If this is normal, I don't know what else to check to try and fix this issue. I did recently replace the fuel filter with one that is supposed to fit a Toyota 4runner, so it's a bit different in shape and wasn't unidirectional like the old filter, and I also recently cleaned fuel injectors and replaced O-rings, and installed a new distributor rotor and cap and spark plugs. But I didn't notice any issues with those back when I installed them, and it was still summer so it wasn't cold enough to cause these problems. Any ideas?
Here is a comparison between the new fuel filter I installed (left) and the old fuel filter (right), if that matters:
You might try one of those cheap plastic see-thru filters mounted on a 45* up towards the engine... I had some issue with filters developing an air lock and not filling with fuel. Mine is not FI so might not be a problem on yours...
Mine does the same, but doesn't sound as severe as yours. We had some 40 degree days a few weeks back, and it would take 1-2 times. Usually, it would start, sound like it was definitely about to die...and then come to life and work fine. So, I don't think it was a cold or warm engine issue, but a fuel pressure issue. I.e., you could drive it to the store, park it for a few hours until it is cold, but then it would still start fine? Is that accurate? I figured it was the pressure regulator somehow leaking pressure over time. Once the line re-filled and pressured up, then it idled great. But, I would expect this to happen any time the vehicle sits for a few days...or whatever amount of time would be needed to significantly depressure back to the tank? Seems our fuel pumps are in the tank. Not sure if they run when the key is on, or if they only run when rpms are sensed (I think the EFI ECU has an rpm input, so I could see both ways). On a small engine with relatively short fuel lines, I would not be surprised if the pump doesn't start until you start engaging the starter.
I think if I leave it long enough until the engine becomes cold it doesn't start right away. The more I think about it the more I believe it's fuel related. Pumping the acceleration pedal does nothing. So the butterfly valve is open all the way and it's getting tons of air but there's no acceleration, which means there's not enough fuel burning. When I turn the key I don't hear anything pumping, so the fuel pump is probably only turning on when the engine runs. On my Honda Acty you can hear the fuel pump running when the key is just turned on to the accessory position, and that never had issues starting. I'm betting there's a loss in fuel pressure as the car sits.
The fuel pump should run with the key in the run position. Even if the engine isn’t running. Try stopping at “on” for a ten count before going to start.
I agree. I just got back to my truck today. It’s been sitting for 5 days. About 50 degF outside. I turned the key to ON and heard fuel pump run for about 2 seconds. Didn’t start it, but turned key back off and then back on. 2 seconds. I did this about 5 times. 2 seconds every time. AFTER all that, I started and it did fine. So I propose a variation to Jigs suggestion. Don’t turn it on and count to 10. Instead, turn it on, count to 2, do this 5 times!! Then try starting and see if any better.
I'm going to try the "key to on, then wait ten seconds" routine on my '92 MiniCab. It too stumbles and dies a few times when the weather gets to -15C and colder.
It might help, but is kind of dependent on whether you have an electric fuel pump. It did help when I installed the electric pump on my Hijet. I can turn it on and wait until the pump starts cutting out as the system comes up to pressure, and then pump the pedal four or five, (eight when it is below zero).
Did anyone find a solution here? I have a Super Carry with the R02A fuel injected engine and am experiencing the same thing. Works fine down to the 40's. 30's require numerous attempts. Won't start in the 20's. It will hit once in a while, but always withing a second or two. After that I have to turn off ignition and start over.
Unfortunately I sold my hijet when the weather warmed up and it was no longer an issue at the time. I do remember adjusting the gas pedal wire to give the engine a little higher idle speed which may have helped a tiny bit.
@jam how , here's a thought: is your fuel summer blend or winter blend? If summer blend, your vapor pressure may be too low as the ambient temperature significantly drops, resulting in hard(er) starts. You can either buy some fresh fuel and add to tank to try and increase its pressure, or store your vehicle in a warm(er) place and see if it starts better. These are just thoughts off the top of my head...someone more experted can opine with additional thoughts. https://www.epa.gov/gasoline-standards/gasoline-reid-vapor-pressure
Go into your profile and add some details on your rig to the signature. It helps when trying to give advice. If you had a carb, I’d say just pump it more. If it is around 30F, then I need to pump my gas pedal, six or seven times to get it to start first try. Gets down around zero, it’s about 12-times. On the fuel injections it varies on how the cold idle system is set up. I’d say ada tank heater, but on my Bronco, I added a tank heater, and it made things worse, becasue the temperature sensor was telling the ECM the engine was warmed up, and it wouldn’t richen up enough to start easily.
Now that it is much colder for my truck, it refuses to start. I tried my suggestion above, and no discernible difference. Just like @MrJPolito , I have an EFI engine. Thus, nothing to necessarily adjust. IF per chance it fired up, it sounded awful -- as if it were running on 1 cylinder! If you touch the gas pedal (rename to air pedal?), it died immediately. At times, if slightly warmer, it would limp idle like this for maybe 30 seconds, then something would suddenly kick in and the engine would come to life (high warm up idle). Once warmed up, started fine, ran fine, idled fine. Hopefully, I will be able to look at it in the next few weeks, but it might turn into months. If lucky, I'll find a faulty sensor that feeds the Engine Control Module. I think there is a water temperature sensor and an air temperature sensor. Perhaps one of those is a broken circuit, and the computer thinks it's always warm? The CEL would come on during the limp idle portion, but would go off once everything warmed up. If no luck, then I'll start playing with the Rotary ISC valve, as I figure that's the device that chokes the engine when cold. Perhaps it is letting too much air in when cold? I tried starting a cold engine while partially depressing the gas pedal -- no effect. But if the choke device is stuck open, then I think I'd see the symptoms I'm seeing (but not sure why there would be a CEL thrown during the event?).
I think you might be right about the computer thinking it's always warm but I never got a chance to look into it before I sold that truck. It acted like the throttle was open all the way at ignition. In my case, hitting the gas pedal didn't do anything to make the start less rough.
That was the idea, but I would guess that would be a permanent CEL? Whatever the issue is, it's enough to turn the CEL on while it's happening, but then off once it warms up and heals. I don't know enough about these CEL codes to know which are stored permanently, and which automatically reset. If a temperature sensor has a broken wire in it, perhaps it is an open circuit when it gets frigidly cold and the wires pull away from each other, thus throwing a CEL. But, once it warms a little, then the wires expand and remake their contact, and that's when the engine suddenly kicks in. I think it'd be easy enough to check...I'd expect some electrical resistance if the sensor was good. I'm not expecting this to be the problem...just speculating right now. After my last post, I read some on the Rotary ISC, thanks again to your link. I noticed it has a bimetallic flat coil spring in it that keeps the valve closed, and then the electromagnetic motor opens as needed. If that spring is partially broke/weak, perhaps it is not closing enough in its cold state? Thus, an adequately cold engine will receive a signal to open very little, but since the spring has not closed the valve enough, it could mimic an under-choked condition (too much air). As the ambient air temperature raises, the valve probably recives a signal to open more, which is why it starts fine once it (or the outside air) warms up some. Again, just speculating at this point.
I also have the somewhat rare S110p EF-ES engine with EFI, AT trans, AC and pushbutton 4wd as well. Mine also still has a cap, rotor and wires instead of individual coils. It's almost as if it was a stepping stone to the later EFI versions to follow since it had some of the older parts and some of the newer parts. I purchased it about a year ago and it ran well for the most part but would tend the idle rough. Looking through all of the available service manuals is helpful, but the majority of the info is on the carburated version with the manual trans. The one statement in the manuals was that the majority of idle issues for this model were related to the IAC valve under the throttle body. MrJPolito touched on it a bit in one of his previous threads. I can still get a good majority of parts for it, but there are some that are just unavailable like the fuel filter, IAC valve, fuel pump, etc. So I pretty much set out on a similar journey where I'm trying to find compatible replacements. I found a compatible IAC valve by literally searching through images of Toyota IAC valves. It goes on a mid nineties Toyota Tercel or Paseo. Here's the Amazon link: https://www.amazon.com/dp/B086VF9S89?psc=1&ref=ppx_yo2ov_dt_b_product_details I changed it out, cleaned the plugs, cap and rotor and put it all back together. It ran better at idle so I went with it. Fast forward to the end of last year and my idle start to get worse and the truck would start to bog down and die when it was warm. It would generally start again, but wouldn't idle well unless i gave it a little gas. I thought maybe my fuel filter was clogged so I found a EFI rated filter from Amazon as well that looked similar to my current one, but didn't have the banjo bolt connection at the top. Here's the link to that one: https://www.amazon.com/gp/product/B0CJ72YZ9K/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 I had to cut the banjo off of the fuel supply hose and connect it with a EFI fuel line hose clamp to handle the pressure. The truck started and ran well, but I made things worse. Once it warmed up it would die and It wouldn't start back up again until the truck was completely cold. I thought it was the fuel filter, but I verified I had good flow to the rail (don't ask me how, but it was messy). Maybe I had bad gas because it had been sitting all winter. So I siphoned the tank and put in a couple gallons of premium fuel—still no improvement. I thought maybe the fuel regulator return wasn't working properly and started questioning the vacuum line feeding it. Then I questioned the other vacuum lines in the engine as well. At this point I was just guessing. I was even more frustrated, and I could only find threads with similar symptoms as mine, but they were carburated/manual models. So I once again checked my plugs, cap and rotor and this time I removed my ignition coil and tested both primary and secondary coils. It tested within spec and I found the Daihatsu Rocky had an almost identical coil if I needed to replace it. Since mine tested out okay I reinstalled it and again thought I had a vacuum line issue. I sprayed carb cleaner around the lines and it didn't change idle at all, but I decided to replace them anyway. So i ordered new silicone blue vacuum lines and replaced each one around the top of the engine and to the chassis. Unfortunately the truck still acted the same after all of this so I thought maybe my IAC valve was bad again. I figured it was not unheard of since it's probably a cheap chinese knockoff part. I tried the AC4025 from Autozone initially because it was local and it had a lifetime warranty, but I found the coolant connections were smaller. So I ordered a new valve on Amazon, waited a couple of days for it to arrived, and reinstalled. This time the truck took a bit to start cold and eventually I was able to start it and get it running but still rough when idling. This time it wasn't dying, so I was able to get my timing light out and check the timing on the top of the engine. When still cold the timing was at the 8-9 marking and ran pretty well. When warm it would drop down to the 5-6 marking and almost die. I loosened the distributor and adjusted in clockwise and the idle improved immediately. Timing was between the 10-11 markings and I turned it back CCW until the timing was right at 8-9 again with the engine fully warm. Finally!!! It idled well and it would start warm or cold. It even adjusted idle properly when the AC was on as well. I truly think my IAC valve was going bad again, but I'm sure the vacuum lines, filter and timing adjustment helped as well. I plan on ordering a new cap, rotor, plugs and timing belt kit soon to keep the truck running well. So that was my journey. I hope this post ends up helping someone else…good luck all.
Timing is the fist thing to check because when the timing belt is changed you almost always need to reset it. Belts stretch with age and new belts are tighter. Good to see progress on this mystery. As more of the EFI models show up, issues like this will be more common.
