Cranks but then suddenly stops.
- Thread starter TurboFreak
- Start date
gona make me go look at cams lol... On a chevy you set timing marks on chain dot to dot.. and then put dist in 180 off 1... :} let me go look at cams
well looks like exhaust opens first with marks lined up.. so thats tdc on the compresion stroke.. so you line it up to #1 with the marks lined up..
I do believe lol
I do believe lol
If his timing mark on the dampener is lined up with zero, his number 1 piston will be at TDC no matter what. The cams are what determine TDC compression or exhaust.
He can have his cam timing perfect but still have messed up ignition timing either with the distributor in wrong or the spark plug wires incorrect.
He can have his cam timing perfect but still have messed up ignition timing either with the distributor in wrong or the spark plug wires incorrect.
not sure if it matters, but, put the cams in backwards? i know i did my timing on the one camshaft and it was opening all of the vavles at BDC (lol i know) and it would still crank over and over and over, just sounded like it was working a LOT harder then it should have been... (not a supra engine btw)
HommerSimpson;1050964 said:
Winner.
I looked through my oil cap at the cam and the top part of the lobe on the intake cam is supposed to be visible, says TSRM. Mine's off to the left. Looks like i might have the cams in wrong?
Is this how the cams need to be positioned? It seems like this would make the top part of the lobe visible from the oil cap.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=52
On this page it says something different and this is how mine currently are. (unless I accidentally switched the cams or something)
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=29
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I'm amazed at how something so simple continues to stump so many people. It comes from not understanding the basics behind how an engine works. That said what's up with the painted marks on the cam gears? It doesn't look like the factory marks are under them.
Rennat: Can't put the cams in backwards. Gear for the dizzy you know...
Rennat: Can't put the cams in backwards. Gear for the dizzy you know...
jetjock;1051378 said:
The factory marks are indeed under the painted marks.
jetjock;1051378 said:
This being said, could you maybe point me in the right direction then?
I don't think it's the cams. Check the #1 piston at TDC by removing the plug and placing a small wooden dowel (about a foot long) in the SP hole. Rotate the crank...if it moves up, you are not at TDC.
No offense meant there guy. Just making a general statement. Your comment about what you see through the oil cap is curious though. Did you do a compression check? Does your finger get blown off the number one plug hole as you bring the crank up to TDC by hand?
Iirc the intake lobs are supposed to be almost straight up or slightly to the right, not left. You may be off a tooth. Do the marks still line up after all this cranking? Did you rotate the engine a few times to check that before putting the cover on? That said all the valves are closed. It should still run as long as the dizzy is timed correctly and everything else is connected right. Sounds like you may have multiple problems.
jetjock;1051425 said:
Hmmm... The timing marks all stay the same even after all this cranking. The intake lobe is definitely not angled toward the right though. Like I said its about 135* at TDC...
If the dizzy was off by only one tooth position, do you think that it would make it do this?
Ughhhhhh.
Make sure the plug wires are in the correct order on the dizzy and are leading to the correct cylinders.
Well, I'm going off memory and a quick look at the book implies the lobe should be off to the right. However if the marks are all good than Jdub is right in that it's not valve timing. Move on to ignition. You're sure the injector wiring is now correct? Can you measure cranking vacuum?
jetjock;1051443 said:
But I remember the lobe being off to the right also! There has to be something related to that...
All the plug wires are in the correct places. As for the injector connectors, I'm 90% sure they are in the correct place. The '92 wiring harness is different in that respect so the references to the wire color's in the searches I've done don't help me...
Cannot measure cranking vacuum. No vacuum gauge.
You still need to have the dizzy timed right. As long as that's good and plug wiring is right it should run on a shot of starting fluid alone. Might want to try that after checking for spark. Then you can focus on fuel. Unplug the fuel pump relay to kill injection when trying the starting fluid. And you know, if you're going to work on cars you may want to invest in some basic diagnostic tools...
True. Thanks for helping me think through this.jetjock;1051461 said:
Owned. :biglaugh:jetjock;1051461 said:
Well, I wouldn't let go of the valve timing thing until I resolved it because I dislike mysteries. Once that happens set all the marks up and install the dizzy so that after it goes in the rotor is pointing at number one on the cap. Then check for spark. Shoot a good dose of starting fluid or carb cleaner into the brake booster port on the manifold, wait one minute for it to vaporize, then crank. If it starts you can go from there and focus on fuel.