1998 Hiace stalling after hillclimb

Hi Guys,

My name is Manu, I'm a frenchie and I recently purchased and converted a 1998 Hiace with a 5L engine, the fastest of all with more horsepower than one can wish for ... or not?

I normally know my way around engines but having an auto gearbox is very new to me. In Europe they are very uncommon, and I have been scratching my head about the following issue which I hope you can help me resolve.

So I had a problem with going over 80km/h, I changed both air, oil and fuel filter, checked my Atf levels and all, but still had a bumpy sensation once those speeds reached, not a shudder, more a 'slight tap' on the brakes. I noticed my kickdown was very high, meaning I could barely accelarate without the van shifting down to a lower gear, so I shunted the Kickdown cable, problem solved, I will however set it at the correct tension once I get a spanner that will fit the tiny space around it.

But, but but but,

Once major issue remains, going up a steep hill or a moutain pass, slowly ok, (before and after the aforementioned surgery) the engine stalls if stop, it shakes and stops much like a manual gearbox would if i full stopped without pressing the clutch. If i manually go from D to 2 or 1, or even N it shifts smoothly, but if I stop just on the brakes, I stall. Any ideas ??

I look forward to reading your opinions. meantime I keep reading

Hi there I have had problems with my 1kzte auto in the past now running perfect , I noted you changed all the filters but did you check the pick up screen in the tank, my tank pick up was 95% blocked with 20 years of crap. This caused all sorts of strange symptoms mainly putting it in limp mode, also has your EGR been disabled on mine this caused a misfire at high engine speed someone had just blocked of the vacuum pipe to the actuator since I reconnected it the misfire has gone, just a few things to check. Good luck.

Hi there JT !

Sorry I haven't replied or thanked you for your input, I actually was on a roadtrip and then got sucked into work !
I think you might have a point there and I will take the tank down to have a look, it make sense that my van starves fuel flow from that filter and had not considered it. I am running very low on fuel today and might have a look tomorrow actually. I do not know if I have an EGR, I looked at my intake manifold to see for gunk/goo and it's all super clean there.

Also noticed my hot idle is a bit low. Not sure how to set that right, I assume on the fuel pump.

Ps: Noticed you live in Holmfirth this place is a little gem ! Love your region !

With the vibration at that speed and now stalling it most definitely sounds like the lockup in your torque converter is faulty. From memory it’s likely the actual torque converter that is broken and the easiest and cheapest repair is to replace the torque converter with a used one.

BUT I’m racking my brain trying to remember if these transmissions have a separate TC control solenoid in the valve body (these Aisin transmissions have 3 or 4?). The lockup TC clutch problem is not that common but it is a thing that can happen. Google “Aisin A340 lockup torque converter vibration” and you should get hits.
With your other idle & running issues something is also telling me it could also be your ECU capacitors. (Search the forum for instructions on this. At this age it is very common to require an ECU capacitor & resistor replacement. Can be done DIY). The ECU controls the gear solenoids including the TC lockup and also the fuel injection.
Hope that’s helpful!

Whoops I mixed up the engines because of the previous 1KZ-TE comment. Not absolutely sure which trans the 5L uses or whether you have the 5L-E which is the electronic injected version but I think the 5L-E might have been for the next generation Hiace. (Either way, the 5L is def not the high power engine option!)

Still definitely sounds like the torque converter lockup is the problem. In the A340 transmissions the TC clutch lockup occurs at ~80kph with overdrive on. With OD off, it occurs at ~60kph.
If the TC remains locked below those speeds, it would cause the engine to stall exactly like a clutch in a manual.

Edit: Looks like you probably have either the Aisin A44 or the A45 transmission. It’ll say on the chassis plate under the carpet flap under the engine cover. It’ll also say on a plate on the side of transmission itself if you crawl under the van below the sliding door.