Hijet 1.3 LPG slow running adjustment AND thermostat replacement


Hello everyone. I've just recently joined the ranks of Daihatsu owners with the purchase of a 2002 1.3 LPG Hijet van. Only have a couple of problems- does anyone know how to adjust the slow running? It's ok on petrol but is slow to the point of almost stalling on LPG. The other problem I have is that it very often overheats from cold. I think it's a dodgy thermostat as the temp guage goes right over to H and beyond, and yet when turning the heater and fan on there's only cold air coming through, suggesting that the thermostat is sticking closed. Eventually after a couple of minutes it suddenly seems to open as hot air comes through the heater with a rapid lowering of indicated temperature. As you can imagine this overheating combined with a very slow tickover makes this van a nightmare to drive in traffic. Any advice would be welcome....

hijet overheating

I have a 1996 993cc hijet which had the same problem. Turned out it was the cylinder head gasket which had gone (apparently they are made of a paper like substance now instead of the old style copper ones) cost over £300 to have replaced and even then the garge forgot to connect a hose which led to the lambda sensor failing and the engine was overfueling. This cost me another £77 to have fixed at another garage.

You should get the van to a garage as soon as possible. This problemm can cause further damage to engine (ie cylinder scoring or warping of the cylinder head.

I am having to replace my

I am having to replace my headgasket due to overheatting problem I had similarly where the temp would go right up then drop after starting to boil over, I thought I would wait to fix it in the spring!
What I should have done was think it through.
Water loss from coolant system (pressurised system for maximum heat transfer):-
1 Check hoses
2 Check rubber gaskets on Rad caps ( two - one on the radiator and one to allow over flow into the reserve tank)
3 Bleed air from system (including heater matrix bleed nipple above rad under front cover.)

I did the bleed but not the checks!
It turned out to be the pressure cap at the overflow bottle was allowing the water to escape before pressure had built in the system to the right point.
This water loss led to a melt down and overheat the gasket and blew it. No oil in the water, no water in the oil! strange... while I waited for new pressure cap I used some rubber to seal the old perished cap it worked but then found steam exiting from the exhuast pipe (place cloth over exhuast pipe and see/smell for steam like when you iron your shirts etc.)
This I knew to be a sign of blown H gasket Sad and then found water in the oil (emulsion) so ordered a new HG and as there are only partial workshop texts available have done what any unemployed guy would - got my hammer out! Hopefully if all goes right I should be back on the road by next week (gotta find my torque wrnch now)

Moral of story - make sure your coolant system is a sealed one, loss of water = bad news. My garage qouted £700 for HGasket replacement and I would have to wait 4 weeks for imported gasket.

I have taken lots of photos as I have stripped the engine to help in rebuild hopefully I wont forget to check for coolant leaks. - 1995 998cc s85 cb42 Hijet

Hijet 1300 efi

Just joined, I had my hijet parked now for over two weeks, overheating problems. I read this morning all overheating problems in this forum, and followed one of the suggestions. Just recently flushed and refilled cooling system, runned well for over a month, until overheating started. I remember not uncovering a little rubber plug for bleeding heater system (thin tube top of engine). Now running fine, ten min job! but not hot air being blown into cabin!!! at least I can drive. Dai1300efi


Hijet LPG heater blowing cold

Not sure, but I have a theory that the water supply to the LPG vapouriser causes a "short cicuit" away from the heater, and maybe away from the rad??? MAYBE restricting the flow of water to the vapouriser is an answer here. After all the vapouriser only has to be warm? to stop icing and to make the gas liquid vapour?

How the hell do you change the stat on the 1300's one of the bolts on the housing looks to me to be impossible to get at.

Tick over adjustment is made by a 4mm hex key to a grubscrew type thing on the top of the throttle body - can't be seen - use touch!!

Your symtoms

Hello mate. My van is the same as yours spec wise. Before i bought it last september the previous owner had the same issues as you have. He paid £200 at Daihatsu main dealer in Bransgore new forest and they changed both thermostats ( Yes 2) and also fitted the modified fan switch changed the spark plugs and refilled the coolant level. It now runs lovely with NO over heating and the fan cuts in and out perfectly keeping the temp guage at the centre ALWAYS!!!!

I also have the lumpy tick over issues too but in reverse order!!! Mine ticks over lumpy but ok on gas but cuts out sometimes when pulling up at traffic lights etc on petrol for some strange reason!!

Because its EFi 16v im having great difficulty finding the ECU port so my man can plug in and find the fault code. My van is a 1999-V reg but same as yours Petrol/Gas 1300cc.

I removed my seats and the rear engine cover to show all the engine and too adjusted the idle screw ( Alan key locker then turn it either way for desired revs). Your ECU plug for the 2002 MY should be visible to the left of the steering wheel under the dash so im told ( A blue multi pin plug)???.

Apart from thses two niggling issues my van runs lovely without hesitation. I do have to let it warm up though in the mornings before i drive it as it overfuels on start up and floods if you try to drive it straight away. It stalls and wont restart for about 5 mins.

Once im on my way i flick over to gas and its fine. I ALWAYS remember to flick back to petrol though before i park it up as it wont start from cold on the gas for some reason.

Im putting that down to it not being 100% set up yet though mate. My heater is fine and blows warm ok and cold if you want it. They are not a heavy duty heater so dont expect too much from it.

Good luck and i hope you get it sorted. Regards. Brendan. ( Zeebra 3) Starsky and Hutch Hijet van!!!!!!!

Ref my last post

Sorry mate, i meant 1 x thermostat and 2 radiator caps were changed on mine.

Regards. Brendan.