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I’m working on my 89′ ford probe GT & it cranks but won’t start! I’ve recently noticed it jumped time since I didn’t tighten it enough & waterpump wasn’t quite tight either…-(I replaced both during headgasket replacement)-been told to do a compression test so I’ve ordered a tester. Also been told by a local mech. thats it’s a sure thing I bent valves atleast trying 2 start the vehicle…He told me I’d notice a difference in height looking at the valves after removing the valve-cover if bent. Any thoughts on any of this? I’ll be sure to post my findings from the comp. test soon aswell…ThankU! Also gets fuel & spark! dumps fuel on spark plugs most of the time & I’ve tryed re-aligning the timing but still nothing! I did find my old #4 plug tip pushed in so that may be bad but I’ve also replaced the plugs recently.
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First off, I highly doubt you bent valves while cranking the engine… There wouldn’t be enough force behind the pistons from the starter cranking over. If the valves were bent, it was probably the reason you thought you need to change the head gaskets in the first place. Did the old belt break? Secondly, I don’t know the engine, but you say it jumped timing? It’s belt or chain driven? How do you know it’s jumped time? What engine is it? Did you get cylinder 1 at TDC when you installed the new belt/chain? More info please.
I would start with the compression test as suggested to be sure you have compression, if you don’t or it’s way low then the next thing to do is a leak down to find out if the valves are the cause. Here is a link to a video I did on this that might help, I’ll also post a link to my compression testing video.
Compression testing
http://www.youtube.com/watch?v=X_tbksFYhl4
Leak down testing
http://www.youtube.com/watch?v=WgrfT0LF … 9BA72160B1
Quoted From Beefy:
First off, I highly doubt you bent valves while cranking the engine… There wouldn’t be enough force behind the pistons from the starter cranking over. If the valves were bent, it was probably the reason you thought you need to change the head gaskets in the first place. Did the old belt break? Secondly, I don’t know the engine, but you say it jumped timing? It’s belt or chain driven? How do you know it’s jumped time? What engine is it? Did you get cylinder 1 at TDC when you installed the new belt/chain? More info please.
I was told I’d hear a noise from the engine that sounds like a wood-pecker if I bent a valve while running & didn’t. Timing belt wasn’t quite tight enough & jumped cause everything was perfectly lined up when I installed the T-belt but was suddenly Cam was WAY off! So jumped time…Did not break, just skipped teeth! & no, I had to replace the headgasket cause previous owner didn’t replace faulty/leaking waterpump! Anyway, it’s a F2t 2.2 turbo mazda engine…& thanx ETCG, I’ve watched those videos & will try the comp. test soon! Don’t have equipment for leakdown test tho
I wonder if the engine is also flooded – reason being if the engine was not starting but you continue to cranks, the fuel injection would still be dumping fuel in the cylinders all the while you are trying to start it, so there may be a lot of fuel in there now. That may cause a low compression reading too because it would wash down the oil on the cylinders.
Quoted From KZ 259:
what does “jumped time” mean?
“Jumped time” means that the timing belt or gear was loose enough that the belt or chain released tension enough and “slipped”, and got back onto the gears of the cam or crank sprocket a couple teeth away from where it should be. This causes the valves to open/close later than they should normally, and causes misfires, possible bent valves, etc. The valve damage would only occur on “interference” engine where the valves extend enough into the combustion chamber that they could be contacted by the piston. Most newer (as in the last 15 years) engines are interference engines, so this could be a major problem. Older cars, like a small block Chevy engine, this would only cause performance issues, and not mechanical damage.
Quoted From johnzcarz:
I wonder if the engine is also flooded – reason being if the engine was not starting but you continue to cranks, the fuel injection would still be dumping fuel in the cylinders all the while you are trying to start it, so there may be a lot of fuel in there now. That may cause a low compression reading too because it would wash down the oil on the cylinders.
It was flooded but I changed the oil & swapped the plugs! Any other ideas? Is it true I’d be able to C the difference in clearence from the top of the valves? Some1 told me to add oil down onto pistons B4 trying 2 start again…will I get better reading from compression check after car sat several days? Think ETCG said to pull my injector fuse anyway during test
You could pull the injector fuse, but a quicker way is to just floor the accelerator during the test – that tells the fuel injection not to add fuel.
As for oil during the compression test, typically you do one ‘dry’, then another where you add a bit of oil in each cylinder and compare the results. If the values go up a lot with the oil then you may have worn rings. I think Eric explains it during his video.
Quoted From johnzcarz:
You could pull the injector fuse, but a quicker way is to just floor the accelerator during the test – that tells the fuel injection not to add fuel.
As for oil during the compression test, typically you do one ‘dry’, then another where you add a bit of oil in each cylinder and compare the results. If the values go up a lot with the oil then you may have worn rings. I think Eric explains it during his video.
YUP, I tryed de-flooding by pulling the inj. fuse but still won’t start! & I meant that I might wanna try starting the car after adding oil but I’m trying to figure out this comp. test! Do I need to pull both the ignition fuses & the pump relays?
To do a compression test, just pull the fuel injector fuse. Write down the numbers you get and get back to us.
Quoted From dreamer2355:
Did you depress the accelerator pedal while cranking over the engine?
And let us know what each cylinder PSI is at.
Won’t make any differnce since my fuel inj. fuse is pulled…Anyway, I flooded it B4 so I’m told that could have caused low compression & to add oil into the plug holes-(onto pistons)- & after sitting over night to try 2 start. On another site they told me anything from overboosting to another blown headgasket. But when it was running there was NO smoke or abnormal noise! When it stalled I had to push gas pedal to the floor to start it & keep on gas in gear or would stall again..After sitting over night it never did more than crank. I was told low comp. on all for cylinders meant it’s flooded! Wut do I do? Plz. help
Quoted From Beefy:
To do a compression test, just pull the fuel injector fuse. Write down the numbers you get and get back to us.
I’ve finally done the compression test & all were about 50psi or less. Some1 from another site told me it means it’s flooded the cylinder walls with gas & just to add oil into the plug holes & after sitting overnight 2 try starting after checking to make sure it’s timing is properly aligned. Any 1 else know wut it means or wut I need to do? I’ll really appreciate all info/advice! Thank-U!
Did you depress the accelerator pedal while cranking over the engine?
And let us know what each cylinder PSI is at.
OK yes it DOES make a difference that you open the throttle when doing the compression test, it’s not just to turn the fuel off but also to make sure the engine can take in enough air as you crank it, no air=no compression. Perhaps you can use the ‘Leak down’ video link that I posted to use your compression tester as a leak down so that you KNOW where the compression is going, that way you can be sure if it’s the valves or not that is responsible for the compression loss.
Quoted From EricTheCarGuy:
OK yes it DOES make a difference that you open the throttle when doing the compression test, it’s not just to turn the fuel off but also to make sure the engine can take in enough air as you crank it, no air=no compression. Perhaps you can use the ‘Leak down’ video link that I posted to use your compression tester as a leak down so that you KNOW where the compression is going, that way you can be sure if it’s the valves or not that is responsible for the compression loss.
After researching & info from other forums I’ve learned/been told my compression would be 0 if valve was bent & I’m not even sure it jumped time. They told me the valves would look VERY different/lower than usual if bent so I’m convinced thats NOT the prob…Like U said & others aswell, cylinder walls flooded from being out of time & after being told to add oil into plug holes I’ve done that & now must recheck/re-align T-belt to proper time! Tried like 20 times but after 2 revolutions around it’s always once again off atleast a tooth! Can’t figure that part out!!!
PS:How can I do a leak down test without compressor? All I get from ppl is an agreement that I’ve flooded the cylinder walls. Been researching non-stop! Thank U 4 your help! I’m always watching your videos & I’ve of coarse subscribed to your videos on youtube
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