Hello guys, new guy here seeking some advice. I searched and didn't find what I'm looking for, so here I am...... I have an early 90's (how do I find what year?) Hi-Jet. The typical 3cyl, 4spd, 4x4. It has 56K miles (or km) on it. When it hasn't been started in a day or when it's completely cold, it is VERY hard to start. I can crank and crank and will do nothing but sputter a little, but it will never pick up and run by itself. It takes about 5 minutes of cranking to get it to start. Once it's started, it has to warm up for about 3 to 4 minutes and then it runs fine...or at least idles on it's own. And when I mean runs fine, I mean, runs with excellent power, it idles perfect, give it gas and it does not hesitate any at all.....nothing wrong when it's warmed up. It even starts back up great once it's warmed up. So today, since it was cold, it wouldn't start like normal. (keep in mind, I am working on this truck for a friend) I changed old fuel out for new, installed new spark plugs, checked for spark. Everything is fine......still no change. This time I sprayed a little B-12 carb cleaner into the carb with ZERO results. So that rules out a carburetor or a fuel issue. I pulled the plugs and performed a compression test with some funky results. COLD TEST: #1cyl = 90psi #2cyl = 50psi #3cyl = 60psi Generally all cylinders need to be within 10% of the highest reading. Obviously this is not the case here. Soooooo, I finally get it running, take it for a 5 minute drive (it does nicely), bring it back to the shop and perform a hot compression test as follows......... HOT TEST: #1cyl = 176psi #2cyl = 168psi #3cyl = 174psi Me, being the mechanic that I am, the hot test seems normal. I don't understand these hot vs. cold readings. If it were to have poor compression when cold and good compression when hot, that would tend to tell me the rings are shot, but in this case, there is no smoke, no oil consuption, the plugs read good, no loss of power and nothing that would tell me there is any internal damages that would make this happen. To me, it seems like there is an issue with the hydraulic lifters not pumping up when cold, OR the valve timing is waaay off somehow when it's cold. Am I missing something here? I have no idea of how these little engines are built, so this entire thing my be just lack of experience or lack of knowledge. Any help would be greatly appreciated. My apologies for the extended post. ~Joe
Take off the air filter/ air intake hose from the carb then cover the carb air intake with your hand when cold then try to start it. See if it will start
Tried that, it will not help it any. It doesn't respond to less or more fuel....open or closed throttle. Well, maybe a little to an open or closed throttle, but not much.
your lifters are not hydraulic and need periodic adjustment..thus could be part of the cause of your cold start odd compression problem..although compression tests should be done warm the cold test seems to indicate a valve too loose to allow enough compression to start. There is a thread with hot/cold specs.on valve adjustment somewhere on here. I would take care of that before going any deeper as it may well be the problem. actually here is the maint manual with specs. and a bunny ..he undersatands the frustration
Lol! Fupa! Quit teasing that rabbit!!! Thank you so much. I will check valve clearance and get back with you guys. Appreciate it!!!! ~Joe
hard start Yea, sounds like valves need adjusting. Should be able to pull up settings @ www.minitruckcentral.com.
That's why I suggested giving the cylinder a shot of oil before cold testing. If it's a ring/bore wear problem the oil will change the readings, if it's a valvetrain issue the oil won't make any difference.
I was having pretty much the same issues with mine. Adjusted the timing and the valves and it fixed it. Check those out.
OldMachinist, I saw your post, and thank you. It was taken into consideration,I have already ruled out rings simply because I have no oil consumption Or blowby. This must be a valve clearance or valve timing issue. Checking the valve clearance out as I type. Just got the valve cover off and came in to get correct specs. Just by a visual without tools, the clearance looks to be good (or very close)......so we will see. Trax....two things..... #1. Can you post a link to how I can set/check the timing in the link above? I can't even find valve clearances at that site. I already seen the post Fupabox made and the link is helpful as in the correct valve clearance, but I'd still like to check the timing since I have the valve cover off. #2.....Your close to my home man. What part of Austin? ~Joe
Ooooooooook......figured it all out. Went to perform the valve clearance test and found my problem. I know I am supposed to perform the check with the engine warm or "hot", but my problem persists when it's cold. So off came the valve cover and I got out the feeler gauge and did a check on the exhaust first. Everything slightly loose like it should be cold. All three exhaust valves need to be set at .011" hot. My engine is cold and I got an average of about .013"....seems to be normal. Went to the intake side which is supposed to be set at .009" hot. I turn the engine over until the exhaust valve is all the way open and check the intake. I found that the rocker arm is tight against the valve. So I loosen the set nut and I have to back the bolt off almost a 1/4 turn before it's loose enough to turn freely. All other intake valves were exactly like this. So, I set the intake valves to about .011" (again, hot is .009"), get in, pump the gas twice and it fires up like clockwork. (being cold and all) I will re-check my clearances later.....I'm just glad to see it start when it's cold for now. So, why/how did the intake valves get tight? Usually they get loose. And how did they looses up when it gets warm? Usually they get tighter when it gets warm. This thing has me all confused!!!!! ~Joe
Glad it worked for you..no answers as to why they would tighten, I've seen tight ones as well(insert dirty comment here)..1/4 turn is a lot to be out, grats on the fix
Thanks Fupa. Well, I took it around the block right after I got it running and I found that I have alot of rocker noise when it's warmed up. I need to perform a hot valve adjustment and see if they tighten up when it gets gold. How much rocker noise should I expect? This is the craziest thing I have ever seen.
Some will have a little noise and some wont have any. Wear and tear / wt. of oil big factor. Location N.Lamar and 2222. Give me a call sometime, 512-217-7456 Terry
Terry, will do if I need some urgent info. Thank you. Oooooook. I went out tonight and fiddled with it a little more. I came to the point to where I personally thought that the valvetrain noise was a little excessive, so I opted to perform a "hot" valve clearance adjustment. With that being said, I set the intake for .009" and the exhaust for .011". Put it back together and I had very little to no noise. I drove it around for a few blocks and put it up for the night. Going to see if it will start in the morning. I will update tomorrow with the cold start results. Also, I have a question in reference to dash dummy lights. Please see THIS thread for details. Thanks, ~Joe
The compression test is always done hot. Your valve lash should just about always be done cold. There may be a hot adjustment. But how hot is hot? Just do it cold and be done is the way I think.
Guys, my apologies for not updating. So I will now. I went out and started up the "noisy" 3cyl and drove it around the bloack about 3 or 4 times to get it good and "hot". So, I came back, immediately pulled the valve cover and preceded with my valve setting propaganda. The exhaust was set to .011" and the intake were set at .009". Before i set anything I checked the current lash and it was waaay the hell off, so i reset it all, started it up and it had very little to no noise. I came back the next morning with an air temp to be around 55 degrees F. Two pumps of the gas and she started right up!!! WOOT!!! So, this entire escapade was nothing more than a valve lash adjustment. Hmmmm, something to remember on the next one. Thanks for the support gents!!!! ~Joe
FYI.....I havnt said this in a while. So here it is again.When trouble shooting a Daihatsu problem I call Leon Barnett @ "Daihatsu Help"(626-968-6764). Even though that most of these trucks are for the Asia market they are 99.9 % the same as the USA marketed trucks. Leon has told me a number of times to call him anytime "thats what I am here for". At some time Daihatsu will pull the plug on him so take advantage of his information while you can. He can steer you in the right direction when trouble shooting. Checking the vales would have been his first suggestion on this truck. Daihatsu has cut his hours back to 3 days a week now and he is on Calif. time. We all know that the info. on this site from all of us is money in our pockets but Leon can keep the sheet rock intack and the doors on the hinges not that I have never got bent on working on a mini truck. LOL. Leon is better than the service book.
That is good to hear your truck is running good. I did not mean to sound like a know it all, lots of different ways to do things. You should gain 3-4 mpg and notice more power with your valves set up. I guess it all depends if your truck is street driven for the mpg, you may not notice if you drive off-road. Yes I have talked to Leon he is a good Character, also Jeff Barnett with Mini Truck Supply in Texas, I also have a guy in British Columbia "West Shore Auto" that helps me out.
Hey, I saw your post about the valve lash of your Daihatsu. I have a hijet S80P which is a 1987 550cc. Currently having similar issue as you I believe. According to Trax and Horns, who has the S80 manual, the HOT clearance is looser than the cold. It's odd...You'd think metal expands when it gets hot and fills the gap? Hot .0098 (Intake) and .0118 (exhaust) Cold .007 and .010 I confirmed the hot ones by translating the japanese specs on my visor drivers side. I noticed in this thread that Joe was using cold lash at .011 and .013 initially? Which doesn't match the manual. I did a little research and found an explanation that might suite the weird gap expansion behaviour for all you who are curious (excuse the canadian spelling). Apparently the cylinder head, rocker arms, block etc are different kinds of metals which can result in a more wider gap when hot. For instance, if the piece of metal upon which the rocker arm "teeter-totters" is aluminum, then when it is hot it will of course expand... which could lift the whole rocker arm upwards and further away from the valve stem, hence widening the gap. (aluminum expands twice as much as steel does per degree in temp change). YET, my truck still won't start at .007 and .010 cold? Leakage test is saying my valves on all cylinders are closing nice and tight at TDC, 5% leakage at 100psi. Very unsure of what is going on, got any ideas? Cleaned the carb float assembly and pin, selenoid valve works, coil resistance test is a pass, distributor-plugs-wires are newish and look ok, fiddled with the ignition timing with no positive results. I am getting very unsure of what the issue is. Symptoms: Cold start problems with some backfiring between turn overs, smells flooded sometimes, once running it's more or less fine except some stuttering-stalling and occasional sudden lack of power inconsistently at higher RPM's. Everything gradually happened over a month, got steadily worse. Initially I had my valves set at .006 and .008 cold on the advice of a mechanic... and recently loosened them to the correct .007 and .010... which is not all that far off. Still has big problems Not sure what to do Tim
