Changed IMS, now missfire codes on all cylinders

[hustler911]

I just got my '99 all back together after changing out the IMS bearing and clutch. I checked timing on the cam shaft ends by marking them and turning the engine 360 degres, everything lined back up. So i fired up the car which ran really rough at first then leveled out. After about 5 min of idling the car started to missfire and almost stall out. I checked the codes and got the 0300 missfire codes for every cylinder. Could the timing have jumped on start up? I did remove all three tensioners when I did the bearing change, and locked the IMS with allen screws (as per Pelican tech article.)

I also had the air box off in my shop for about a week which may have got some dust on the MAF.

[JFP in PA]

I hate to be the bearer of bad news, but I for one am not a big fan of using the Allen screw method to secure the cams while changing the IMS. Besides not really positively securing the cam drives, this method can also move the gear on the rear of the shaft (which is a press fit from the factory), causing the chains to be off axis and cause no end of issues that can only be fixed by taking the engine apart. While some have success with the Allen screw method, some have also had major problems. We pull the green cam plugs and lock the cams down with fixtures while doing one of these upgrades, which eliminates any chance of problems.

That said, you should have the engine scanned by the OEM PIWIS, a PST II, or the Durametric software to determine the current camshaft deviation values before moving further. These engines’ are supposed to be +/- 6 degrees; if yours does not fall into that range, the cam timing is out. Normally, we scan all engines inbound for IMS updates both before and after installation to verify everything is as it should be.

Edited May 4, 2012 by JFP in PA

[wvicary]

Personally I wouldn't even run the engine at all and recheck all your timing marks. I'll assume there were no running issues before the work was carried out.

[hustler911]

I have ran some checks with the Durametric and got a bunch of codes again 0319,0318,0316,0317,0300,0301,0302,0303,0313,0130,0314.

I checked the cam deviation and bank 1 is 0 deg. Bank 2 is 3 deg.

The timing shows 5-11 deg at idle and 27 deg at 2000 rpm.

This should mean that the timing is OK shouldnt it?

I did however notice that when I take the oil cap off there is no suction what so ever. Is it possible i knocked something loose on the AOS that would cause all these codes? The car had lots of suction and a noticable drop on RPM when I removed the oil cap before I did the engine work.

[JFP in PA]

Cam timing looks fine; if you do not have any vacuum at the oil cap, start by looking at the line that supplies vacuum to the AOS and also check the dipstick and oil filler tubes (they are often disturbed when doing the IMS): you sound like you have a vacuum leak.

[logray]

+1 to previous post.

[hustler911]

Thanks guys,

Found a huge vacuum leak at the AOS. I fixed that and reset the codes again. Car runs perfect now, no more codes.

[roadsession]

Excellent news!

[phillipj]

Awesome news! Congrats on the excellent work... :thumbup: