Good morning,

I've got a 1993 3.0 3VZE in a pickup. In 2019 @ 212,400 miles I did a full rebuild of the engine (minus injectors - I replaced 2 from Advance Auto because the tips were broken). Ever since the rebuild it has seemed especially weak, almost like it had a little hesitation. It hasn't been bad enough to worry about it too much, and I assumed it was probably one of those 2 injectors I replaced from Advance.

The other day it started missing terribly while accelerating, but was fine at an idle. I had a set of 6 injectors that I bought from a guy that were brand new (aftermarket), so I decided to take the upper plenum off, replace the injectors, and put a set of plugs in. I did just that, and found the plastic cap had fallen off the back of the fuel damper, and the screw had fallen out of the back of the damper. I purchased a new damper, fuel filter, air filter, and 6 new Denso Iridium plugs. I put all those parts in along with the injectors. Now the truck will not idle unless I take a vaccum line off the plenum. I can tske the PCV line off, or the brake booster line off, and it will idle. As soon as I put the hose back on it dies. It also seems to have a miss when I open the throttle up. I have unhooked each spark plug wire from the distributor while it's running (one at a time) and can tell a difference for each one.

BTW, I also put a new idler pulley/water outlet on for the timing belt. I made sure both cam pulley marks were lined up with the marks on the cover, and I set the crank pulley mark to 0, then put the timing belt on tight, leaving all the slack to the adjustment pulley. I tightened the adjustment pulley down, put the spring back on, and all marks were still lined up. I've tried checking the timing with a light, but because I can't even get it to idle correctly it jumps all over.

I would greatly appreciate any tips/ideas. If you need more information just let me know!

Thanks!

P.S. the truck is now at 274,845 miles

Another update... I just tried to remove the cold start injector fuel line, and it was under a good bit of pressure. It started spraying fuel, which I've never had happen before. Usually it leaks a little when I take it off, but it doesn't spray fuel. Not sure if that helps anything.

 

Codes? I would expect code 26. When you pull a vacuum line, you're leaning out the mixture. Based on your description, your "new" injectors are putting in so much excess fuel that the ECM can't compensate.

Remember that a timing light checks ignition timing, your cam pulleys affect valve timing. They're only loosely connected; you can have spot-on ignition timing with cams way off.

When the engine stops, the fuel rail is still pressurized. Unless you have a leak somewhere. If your fuel pressure damper was leaking, you may have (inadvertently) fixed that, so when you now remove any pressurized fuel line it will spray. BTW, the pair of crush washers on the CSI line are one-time-use, so you'll need to replace them. Cheaper than dirt, but I can only find them at a dealer.

 

Well, thanks for the reply, but I fixed it. Apparently those aftermarket fuel injectors were no good. I swaped them out with the old injectors (which had even been laying in the bed of the truck) and it runs just like it has been since I rebuilt the engine.

Thanks again!