The AUSubaru.com.au Forums

I just had the heads off my ej25 quad cam, due to headgasket issues.
I had them skimmed, and reinstalled them with genuine gaskets, new water pump , new thermostat and a new timing belt.
The car seems to have less power on acceleration now, and occasionally the check engine light comes on for a few seconds, then goes out. Otherwise it runs fine, just sorta....flat.
I have checked and rechecked the timing on the cams and it seems fine, all the marks are in the right spots.
Would being a tooth out on the crank timing give this result?

Battlewagon wrote:Would being a tooth out on the crank timing give this result?

Yes it would! Make sure you've got the crank in the correct position in relation to the cam timing. One tooth can make a huge difference.

But it shouldn't throw a code. I'd check the codes to see what comes up. Since you've had the heads off the intake manifold has been off - so a sensor may have been knocked/damaged in the process.

Or it could just be coincidence!

I hope this helps.

Cheers

Bennie

Knock sensor...

Sent from my HTC Velocity 4G using Tapatalk

Most common problem I see happens when people fit their own Timing Belt is the position of the Crankshaft Pulley. I must have seen half a dozen come through the shop with the timing set to the little arrow on the crankshaft pulley.

There is a small notch on one of the tabs that comes off the Crankshaft Pulley. That should line up with a notch just next to the Crankshaft Timing Sensor. From memory, this will have the little arrow sitting at 3 O'clock.

Then the Camshaft Pulleys should be setup with the ' ll ' marks aligning together, which should make th ' l ' marks line up with the inner timing belt covers.

If this is out then the car will be very under powered and will set off the ECU light as it's getting a weird timing count from the sensors.

One major point to mention here is, when removing the belt from any quadcam engine, make sure the camshaft pulleys don't spin. If they do, there is a chance that the Inlet and Exhaust Valves collide. More than likely, this will cause damage as the valve stems are very small and doesn't take much to bend them.

Your valve timing could be still be incorrect if you took a lot off the heads.

You then end up with retarded valve timing, although it may look near enough correct.

If you have setup it incorrectly though, you'll be very lucky if you haven't damaged something.

Your engine light will be cam/crank sensor correlation codes.

The heads were barely skimmed, I had them done by a guy I've known for years and he said they were probably the best set of EJ heads he'd seen in years. (McNaughtons at Wallsend.) He used to do my race heads, when I raced speedway.
Pity he's going to shut up shop soon, we are losing the really skilled, old-school engine builders so quickly these days, and finding someone you trust to do the work right is getting hard.
I'm going to whip off the balancer and front covers again this weekend, and have another look at the timing.

Have you checked the engine fault codes yet? That would be my first thing.

Sent from my HTC Velocity 4G using Tapatalk

Battlewagon wrote:The heads were barely skimmed, I had them done by a guy I've known for years and he said they were probably the best set of EJ heads he'd seen in years. (McNaughtons at Wallsend.) He used to do my race heads, when I raced speedway.
Pity he's going to shut up shop soon, we are losing the really skilled, old-school engine builders so quickly these days, and finding someone you trust to do the work right is getting hard.
I'm going to whip off the balancer and front covers again this weekend, and have another look at the timing.

Yeah, you'd need a fair bit off before you'd get out of wak.

Once you've got that balancer unbolted and the Camshaft Pulley covers off, just turn the engine until the ' ll ' marks line up on the inlet and exhaust pulleys, then pull the crankshaft pulley off and see if that little arrow is pointing to 3 o'clock (as it will be very hard to see the other notch with the centre cover on).

Alex wrote:Have you checked the engine fault codes yet? That would be my first thing.

Sent from my HTC Velocity 4G using Tapatalk

Very good point there Alex.. worth finding out just for future reference. Remember to connect the black plugs for codes in memory.

Exactly which black plugs, where? And how do I read the codes? Is there a thread you could direct me to?

Just above the drivers feet, you should see 2 sets of plugs (one green set and one black set). Find the black set and join them together, then turn the ignition to on (dash lights come on) then the fans should be cycling and hopefully the Check Engine light is flashing. Count the flashes (Long flash = 10 and short flash = 1) i.e. 2 long and 4 short = 24

Here an excellent write up by AP.. speaking of AP.. where has he gone to?

showthread.php?t=14372