This may be the most important point made so far. Having a "method of operation" can make all the difference in this kind of work. But it can take a while to train your brain to consider the diagnosis and the actual repair as two different goals. Sometimes a simple part swap can be a cheap and easy way to fix a problem. After that works a couple times it can become your "go-to" means of diagnosis. But if the problem is more complicated the part-swapping approach can quickly become more expensive and frustrating. And trying to do this kind of work online, where information can be scarce and inaccurate, just adds to the complexity. It really helps if you can convince your brain that diagnosis and repair are seperate goals, with one leading you to the other. Combining the two can lead to the "diagnostic goose chases" that 31Vicky mentions. Or as a friend of mine who runs a small computer repair business refers to them, as a "screaming monkey fight".
Ha Ha, Im dying to set up a motor into a no start condition for 31 vickey. But id take him out of his comfort zone and stick him on something he wasnt familliar with to do it. I had some some stumpers over the years, mostly drivability problems that were intermittant
Bring it over. Ill hunt your zebra. Ill ask you about 10 questions, you can not lie, and its on. Brand new build or formerly reliable daily driver makes no difference. Like taking candy from a baby,
Going on a Road call for 2010 Toyota "no start" this am but was fine yesterday. So what do you think I'm taking with me? Fuel pressure gauge, noid lights, and test light and a can of carb cleaner. Maybe it needs a tow maybe not we will see. There's only a few things it can be. Lost the fuel pressure for a YTB determined reason. Lost the injector pulse signal for a YTB determined reason. Lost the ignition for a YTB reason. Lost some other major sensor for an odd reason. Aonemarine was there and rigged it for no start Fine yesterday is key clue- never been on the road is a different thought process.
Ha Ha, we (oh hang on ) I should start a new thread titled " My problem and how I fixed it" A thread about what your car was doing to give you fits and how you got it cured.
First look at your methods of determine what you stated to be true. Air fuel ratio or air flow- look at the read valves if you are certain the carb is good. Carbon ash build up in the exhaust tract if its a 49cc weed wacker type
The 2 stroke is not crak seals... I may have rigged the toyota but I would ask if they are using the same key they used when it was running......
Hope this doesn't degenerate into a chest thumping competition. to Shaner's74, as has been said, I don't think those Vortec heads can take the amount of lift you have, without parts whacking into each other. Just one more thing to worry about. Ralph
do it.... but in the past i have found out the keyboard commandos CAN NOT answer the questions, or even keep up, in live conversation. nothing personal Phil or 31 - i'm just saying i have respect for ALL hotroders especially you 2
too late..... NOW BACK ON the original subject or take it to the pm's and fight among yer selves ....lol
Yea, we will just drop it, 31 vickey knows what hes doing... But it would be fun to stump him... The outboard I was speaking of was an old crank ported motor, reason it wouldnt start...Wasps nest in the crank....
The vortec heads are the upgraded version with the valve springs for higher lift apps. I haven't done the leak down test yet, I have to run to HF and pick up some guages. Still no compression on those 3. I did back off the rocker arms so all of the valves are closed. I applied air through the comp tester fitting to see what happened. DISCLAIMER--It didn't have a 100% seal because I had a rag wrapped around the air chuck. The air came back out of the spark plug hole. Removed the rad cap and checked for bubbles-nothing. Pulled the dipstick to check for air in the crankcase-nothing. Then I shoved a piece of plastic in the spark plug holes on other two cylinders and applied air to the third to see if it would blow them out--it did not. I did the test on each cylinder with the same results. Once I get the leak down test done that should narrow things down.
Just for grins, although pretty sure not the problem this time. A long time ago, a member of my marriage family was mowing the yard, and ran out of gas. Went to the shed, got the gas can, and refilled the tank. Mower would not start. Was an older mower, and my marriage-Dad had another, so finished the yard, and then took the engine on the first mower apart (it was due for a rebuild, and he already had the parts). Rebuilt the engine, and it still wouldn't start! Reason: family member (not to be identified here) had grabbed the kerosene can (even though it said gasoline). Kerosene just wouldn't fire, even in the rebuilt engine! We (all except un-named family member) all thought it was a good joke on my marriage-Dad and myself. At least we got the engine rebuilt. Apologies to the OP, but since the thread was already hijacked, couldn't resist. Jon.
Man some pics of this will help a lot- What kind of compression tester are you using ? Mine as a oring fitting that seals on the same plug sealing surface. Off of this fitting is a hose with a male air hose fitting. To the male air hose fitting you attach the gauge which has a regular female air fitting or to the male fitting an air hose. If you have ZERO compression in a cylinder a leak down test won't help you. You do a leak down test to determine (gets tricky here so be careful) the amount of leak down. With no cylinder pressure being built there's no leak down. This test will show you a rate and percentage of pressure lost over time. You loose zero pressure in zero seconds of the zero pressure you built. I may not be understanding your post, if that's the case please forgive me... Earlier 3,5,7 have zero compression, retest shows zero. You then backed off the rockers and now have no air escaping? You need to hear it but how can you hear it if there's air pissing out of a rag around an air hose. Really can't see how the test is valid but and this is a big BUTT so take this for what it's worth (not much) If all you did was loosen the rocker adjustment and now it has no air escaping then what would you say the original problem was?
leak down tester,old spark plug cut off the outer electrode and snap the ceramic off both ends,punch the ceramic out of the center.make sure it's clean and hollow.install in cylinder head and stick your rubber tip into it it should seal really well.tape a rubber glove over the ex pipe.presurize the cylinder for a while and see if you can blow the glove off.also this is with rockers off.throttle plates wide open use your ear or a feather over the carb,if no leaks evident maybe rockers were tightall spark plugs out and piston up you should be able to turn the engine with air pressure if all is right inside.good luck sorry for all the grief
I was going to use the leak down tester to add air to the cylinders in a controlled (sealed) manner to see what happens. If the pressure holds the valves were most likely not adjusted right hanging open letting compression out. I can also check the coolent for bubbles and the crankcase again.
If he wants and we can work it out I'd like to try to take a look at it for him. "If you have ZERO compression in a cylinder a leak down test won't help you. You do a leak down test to determine (gets tricky here so be careful) the amount of leak down. With no cylinder pressure being built there's no leak down. This test will show you a rate and percentage of pressure lost over time. You loose zero pressure in zero seconds of the zero pressure you built" I was thinking I'd hook up my leak down set to it or let him borrow it to see if it had the valves adjusted too tight. (I've kind of suspected this from early on) You don't think we can hook up a leak down set and diagnose a hung or bent valve because the cylinder wont hold pressure? I have to say I've done it several times.
I see my words but no quote. Yes you can use a leak down test fitting. (Buy more stuff ) However a "leak down test" as in measure of the cylinders pressure loss rate won't do you any good on a cylinder that has no compression. My compression tester (as pictured in the post) has that capability and that fitting. I'm questioning the compression test equipment and there for the results based on shaners comments.
My plan was to use the fittings to add air to the cylinder to see where it goes. The valves are closed so if air comes out of the exhaust or intake there is a valve hanging open for any number of reasons. If it comes out the dipstick tube it's rings, hole in piston or cracked block. If air bubbles in the radiator it's a blown head gasket. This isn't likely since there's no coolant in the cylinders or oil. Washed out cylinders? I squirted oil in each but was unable to regain compression. I had that happen before on a different engine but it was only one cylinder. Three cylinders with valves adjusted wrong all in a row? If that were the case it wouldn't have run before? The tester I have is like yours but it doesn't have a fitting to connect to the air hose.
No need to buy more stuff. That's why I'm going to loan him my leak down set, or better yet go over there and do it for him. Isn't it still a leak down test even if its 100% loss. I guess you can call it a cylinder pressure test. I just always call it a Leak down even if I'm looking for a failed component rather than a slight pressure loss. Either way it needs to be done.
maybe i missed it and sorry if i did but did you ever retry the compression test? i remember you said you were going to but dont remember you posting results again. i would try it a few times and make sure you get the same results every time. having no compression is pretty significant and should be easy to hear with the leak down test. even if you used a rag at the nozzle, with no compression you would still hear the air escaping somewhere else also.
The Jalopy Journal
