Engine rebuild, now low idle, backfire, vibration

[soldave]

Have been OK, I bought this Evo III which had a blown headgasket and a few other issues too. The engine would fire up and idle ok, but had a water pump leak and had bubbling coolant after warmup. So I took it apart, replaced the pistons and rods with ones out of an Evo VIII, replaced water pump, balancer belt, timing belt, pulleys, filters and all fluids. Also took the CAS and cams off for a thorough cleaning.

Today it finally got back together and I tried to fire it up. Wouldn't turn unless I was quickly going on and off the gas, when it would almost start and backfire a bit. Moved the CAS all the way one way and tried again and after a bit of a struggle it fired up into life.

So that's the good, now for the not so good. The car doesn't sound right, and I don't think it's just because it's a rebuilt engine and things were seating themselves as I had it running for a good 15mins or so. It's got a bit of a vibration and at 1,500rpm is at its worst. Higher rpms (3,4000rpm) the vibration and noise goes away but it can give a little misfire too, and if I let off the gas completely from those rpm levels it wants to die; normal idle is also about 500rpm which is way lower than it should be and that it was before the rebuild.. I tried moving the CAS back but that just makes things worse.

All I can think of at the moment is counterbalance shaft sprocket for the balancer belt going out of phase when I then was turning everything to put the timing belt on. Other option that's come into my head is the timing could be a tooth off. That might explain the CAS being all the way one way making the idle a little better and the backfiring at idle go away. I mean, I couldn't alter base timing one way if I took a timing light to it and found it was out at the moment. But those are all I can think of - anyone else have any other ideas?

Took video and will post it up once I get home from Starbucks after my caffeine fix.

 

[rlacasse1]

It sounds like your timing to me bro. Have fun with it.

Also, make sure you have your firing order correct first. If that's not it, then I would say rip the timing cover off and check it out.

 

[soldave]

You mean that my spark plug wires are going to the right plugs? Yeah, I had a look at that but it's not it. Heard a little clicking at very low idle; as long as it wasn't the sound of valves hitting pistons I'll be happy! See what you can get from the video a little later.

Thanks for the quick advice

 

[rlacasse1]

Yeah, I was saying to check if your plug wires were correct.

If it was a very light click then it might have been your lifters ticking a little.

When you timed it the first time did you rotate the engine over by hand 2, 4, or 6 times (as you can see we're going on even numbers here) to make sure that it was in time for sure.

 

[soldave]

Yeah I rotated the crank 6 times clockwise by hand to make sure everything was in phase.

Here is a video of the idling and a bit of revving:

[youtube]7zZQb4guo68[/youtube]

 

[Fitzi722]

I am having the exact same noise happen, except between 2000-3000 rpms. It sounds like it's coming from the timing belt side of the motor. It's on a 1G btw. It's depressing because I just finished rebuilding the head and this is happening. IDK what it is.

Any ideas would be greatly appreciated

BTW no balance shaft on my car, previous owner deleted it.

 

[soldave]

Well my problem was due to me being dumb and messing up the spark plug wires. Sorted out the firing order and it cleaned right up

 

[broken_eclipse]

I could only listen to the first 30 seconds or so of your video but it sounds like you're not firing or have bad compression on 1 cylinder. Have you done a compression/leakdown test?

Edit: looks like i was few minutes too late, Glad you got it figured out!

 

[Fitzi722]

So firing order / fouled spark plugs is what I should be looking for?

 

[soldave]

Well they are things you can check very easily.

 

[Fitzi722]

Very true. It's late so It will probably be checked in the morning. Thanks for the Info

 

[CrossDSM]

Hey, i have some wired stuff going on with my 1g talon!
tomorrow i'll make a video with my problems (the vid on post isnt mine, but i have the same thing, replaced the ecu and it didnt work) here is a link: HELP!!