So a few days ago i bought a 93 RS from a guy off Craigslist. I saw the car run and then about an hour later he called me up and said it broke down. He thought it was the distributor but it turned out to be a snapped timing belt. I lined everything up and put an old timing belt i had on to do a compression test. Every cylinder came out to just about 80-85 psi. So i figure that i bent some valves but why are all the compression numbers the same? If i had one of the cams a tooth off would it cause this? I was thinking maybe the valves are out of adjustment but i doubt it would cause a problem like that. Im also unsure of the accuracy of my compression tester so im gonna get ahold of a leakdown tester and see what i can find out from that. The motor has 209k on it so it may just be better if i swapped in a lower mileage engine. Any thoughts?
- your cam n cam gears arent lined up correctly
- rings or wall is worn
- valves are slightly bent
I took the timing belt off and tried retiming everything and still got the same results so i think that i got the cams lined up right. The problem is im not sure if its number 2 or 3, and with a leakdown test wouldnt the air just take the path of least resistance? I also tried starting the car but it wouldnt start. Is that not enough compression for it to start?
it should be enough to start it…poorly albeit. triple check that timing. because it really sounds like that’s your problem. if you’re absolutely certain that it’s spot on, chances are you bent valves, since it wasn’t running on 85psi before the belt broke
Yeah im pretty sure the timing was right on. I pulled the head yesterday and everything looked good, but the valves could be slightly bent i guess. I guess there really isnt a way to tell without taking them out. If they arent bent i have no idea what could be wrong with it.