Won't start?

cocuzzinator · Post by **cocuzzinator** » Sat Jul 03, 2010 7:20 pm

I think it might be that just the timing is out of whack but I'll give the situation;

'99 neon with DOHC (bought the car with a DOHC & spun bearing on cyl. 1; originally had a SOHC but owner swapped it himself), bought another engine with overbore high-comp pistons, crane cams, adjustable cam gears and some other random goodies that I probably don't know about yet exist (the guy needed it gone asap & he couldn't find a lot of the paperwork so what he did have is all that I know about). DOHC apparently came from a '95 because all of the electrical plugs & everything were round, not flat pin.

Anyways, I got the motor in the car & when I try and start it it just cranks. I don't hear anything which would indicate that the spark plugs are igniting the fuel (the exhaust pipe had a huge lateral crack in it so I removed it completely & can hear compression from the pistons through the header).

I've checked the fuel pressure on the rail, & when I turn the key I have pressure. Tested the plugs as well and they are all sparking. Only thing left that I can think of is that the guy I bought the engine from set the cams out of time or that I have a bad cam pos. sensor (bought a new crank sensor so I'm pretty sure that one's not bad). I'm planning on going through the process of a timing belt change & taking off the valve cover to see if it's timed correctly sometime either this weekend or next.

Anyone have any idea what might be wrong?

ricker91878 · Post by **ricker91878** » Sat Jul 03, 2010 10:06 pm

I would check the compression, car would still prob start but run ruff, I had the same issue with mine, would turn but not turn over, ended up being the pcm, you may have to try another computer, I would get one from a junk yard and start there, I replaced almost every sensor in mine and it ended up being the damn computer all along. And I have a similiar setup, I did a engine swap my car is a 99 and it had the dohc but was blown, found a 96 with 98000 miles on it dohc, and we changed over sensors and replaced, it was rediculous but the car runs great now. Good luck hope this helps.

INVUJerry · Post by **INVUJerry** » Sun Jul 04, 2010 4:48 pm

Unplug the cam position sensor and crank it again. It'll start after a few seconds of cranking.

cocuzzinator · Post by **cocuzzinator** » Mon Jul 05, 2010 4:39 pm

Hey guys, thanks for the suggestions.

Swapped out the PCM with another one I had (guy I bought the engine from also gave me a laundry basket full of parts) & tried to crank it, still nothing. Tried unplugging the cam pos. sensor and cranking it a few times, then plugged it in again and cranked it; still nothing.

Haven't taken it apart to check the timing yet (had to fix a leak in one of the coolant inlet tubes so that is what I spent most of the day doing) but I plan on doing that some-time next week.

INVUJerry · Post by **INVUJerry** » Mon Jul 05, 2010 6:52 pm

When you unplug the cam sensor, it has to crank quite a bit before it'll start. Pull the fuel rail off and see if you're getting fuel when you crank.

cocuzzinator · Post by **cocuzzinator** » Mon Jul 05, 2010 6:55 pm

When you say unplug the cam sensor do you mean leave it unplugged while I'm cranking it or plug it back in while it's cranking?

metal_gear_jon · Post by **metal_gear_jon** » Tue Jul 06, 2010 8:15 pm

Leave it undone, then crank. All 98-99 pcm's can fire the car without cam reference.

cocuzzinator · Post by **cocuzzinator** » Sat Aug 07, 2010 6:28 pm

Turns out that the intake camshaft was 180 degrees out of line so it the engine was trying to fire when valves were open.

Thanks for all the help though!