Need help with first engine run......

[Skids]

So I fired my engine after a re-build for the first time. It fired and ran great at 2100 r.p.m. (to break in the new cam) for about 1 minute..............then it missed...........and missed again........then it massively backfired and quit. I can't start it again at all. Fuel pressure is good..........the exhaust stinks of gas. But it won't fire again. I checked all connections, all fluid levels........lots of battery juice. The ignition system seems to have just died. Any ideas????

P.S. It ran great for one minute........so it's obviously set up right. HELP!:frown:

 

[Skids]

Double post..........


Sorry posted in General Tech... Thanks.

 

[Phoneguy]

I think I would check the cam sensor first. But do the usual troubleshooting.
air, fuel, spark. Check your grounds, ecm fuses, and the connection by the battery. Frustrating after building the engine, so sit down relax gather your thoughts and re attack. You will find the problem. Good luck.
Bryan

 

[Skids]

Thanks........R.

 

[Skids]

So I finally found the problem.......one of the connector pins on the cam sensor was crushed.....straightened it out, plugged it in........ran like a charm.........TILL IT GOT HOT. Then..........tick-tick-tick-tick...........friggin' loud. My innitial thought was another spun rod bearing. But it's definitely valvetrain noise. I let it cool down, then fired it up again........nice and quiet, but as soon as it gets hot, the ticking comes back.........LOUD. You can hear it from 30 feet away. It goes away at about 2500 rpm. I did put a HV oil pump in during the rebuild......if that would make any difference. Any ideas???

 

[turbofabricator]

What rocker arms do you have? How did you set/verify lifter pre-load? What is the oil pressure when hot? Maybe you have lost oil pressure. Get a good oil pressure gauge on it and let us know.

 

[Rosewood T-Type]

Somebody explain how the cam sensor caused this when its only used for timing the injectors for initial start up. I mean if you unplug the cs once car is running it will still run, no effect!
How long did you prime the motor prior to start up,did it have oil pressure on the gauge?
Sounds like you spun a cam bearing and seized cam to the bearing(Dont ask me how I know this ha ha).
As for ticking your cam is shot. your breakin was fuc..d up when car died.
Sorry for the bad news just put in a new cam and make sure you get all the way through the breakin with a good diesel oil like Rotella (high zinc and phosphorus). todays oils are designed for roller cams not enough additives for flat tappet cams.
Doug

 

[TurboBob]

Somebody explain how the cam sensor caused this when its only used for timing the injectors for initial start up. I mean if you unplug the cs once car is running it will still run, no effect!
......

Doug

It could have come loose while the engine was running. If the connection was intermittant, then it could have caused a false cam pulse at the wrong spot, de-syncing the ignition. (the ignition re-synchronizes on every cam pulse)

Bob

 

[Skids]

Sounds like I'm going to have to pull the engine again. I put tons of high pressure lube on the stock cam when I installed it. I also put in new lifters......I primed the engine while on the stand with an electric drill for a few minutes, rotated the crank 90 degrees and ran the drill for another few minutes. Oil appeared at the top of all the rockers. The valvetrain is stock, installed as per stock specs. All components were in good shape.

 

[Skids]

Would a spun cam bearing tick like that........it's very sharp and regular........kind of like a lifter failed????? Ideas?

 

[TurboBob]

if a lifter has an air bubble in it, it may take an hour to clear out.

Cut your oil filter open and drain your oil and look for metal.

does it sound like one lifter, or lots of them?

what is your oil pressure once warm (at idle)

Bob

 

[Rosewood T-Type]

I might be wrong but if you spun a cam bearing then no oil is getting to cam and lobes will get wiped.

 

[Jerryl]

Now, I am no expert and from 2000 miles aways this is difficult, but, I doubt you wiped the cam that bad already to cause the noise like that.

So, let try to stay conservatively possitive
There have been stories of the timing gear bolt comming loose casuing the "tick".

Who assembled the engine?
You have good oil pressure?

Are you sure the noise is "inside" the motor"?
Did you set the pump clearances?

Probably (hopefully) something simple ............
Damn, I feel for you.

 

[Rosewood T-Type]

I'm not trying to start a panic but he said he fired his motor it ran at 2100 for a minute then miss miss then Massively backfired. I'm sorry but that flat tappet cam is Toast.
Also have you checked oil pressure with a gauge just because you have oil at the pushrods does not mean you have enough oil pressure it just means the oil pump is working. It also does not mean oil is getting to the cam journals.
Doug

 

[Skids]

I'll check the oil pressure........the engine runs nice and strong right now. I took it for a spin around the block and lots of smooth power at 9 psi. The loud ticking is still there though.........but only when hot. I'll get back with the oil psi.

P.S. I built the engine.....it's my third 3.8 turbo......the other two are a couple of years old and consistantly in the 11's.

 

[Skids]

Oil pressure is 55 psi cold, and 16-18 psi hot at idle. Off idle in park, it spikes to 55 psi hot..................????? It didn't start to tick until the oil psi approached 18 psi at idle. I think the lifters are bleeding down. Any ideas??