Sludge

OK I set out this weekend to replace the idler pulley that goes over the water outlet. Since I had to rip out everything to replace the pully. I also replaced the T-Belt, Tensioner pully, cam shaft seals, water pump, oil pump, and the 3 drive belts. While taking the timing cover off I noticed that the driver side cam sprocket was on backwards :pat: . Done by the previous owner when they changed out the belt. I had the truck for 6yrs with no issues, so when I replaced the cam seal I put the sprocket back on the correct way. Lined up all the marks on the cam and crank shaft, installed new T-Belt and did the 2 revolutions and when the crank marks lined up the cam marks was off about a half a tooth or less to the left of the marks on the cover. Same results after several attempts, thinking everything was fine I put the truck back together.

When I started the truck back up it turned right over with no issues, but after a few mins running the idle dropped to about 400 rpms. I not sure if the belt is off one tooth or not or the truck was tuned different be cause the cam sprocket was backwards. Would the belt being off just make the engine run rough? or lower the rpms? or both. At 4000rpms the engine was running nice and sounded good. Also I haven't road tested the truck yet as it was getting late and I was tired took me about 15hours over the weekend to completed this task as I wasn't in a rush. I plan on adjusting the Idle screw and cleaning out the TB along with checking the timing also. If anyone has any suggestions or answers about the t-belt and rpms please let me know.

rebult junk

i just did a reinspect of my timing belt that i put on 4 months ago i thought i had a cam off or something like that so i took it apart and all marks line up on the money still trying to find out my ruff idel and some times it pops back through the intake with low idel when it is hot out side the hoter it gets the lower the idel afert all that i toke the dis cap off and found some craking inside the cap my point is ck the eazer stuf first i would have saved my self 2hr by cking the eazer stuf first

SupraSport

This is the 3.0l ???

snap-on

I know your timming will affect your idle a little.

Sludge

Yeah is a 3.0 4WD auto

Sludge

Less then 2 years ago I did a tune up on the rig by replacing plugs,wire,cap,rotor. Im going to adjust the Idle screw to see if this will help and pick up a timing gun to check out what my timing is at. As for the air intake tubes I will double check them again for cracks when I clean out the TB. Then check the TPS. UGH that is alot of tedious litte work to do. Not sure why the idle would be off 400rpms just by changing the belt unless I did something wrong on the belt install. O well I will bbl with some results and checking in to anymore suggestions.

Sludge

Welp I ripped everything back apart this afternoon and redid the timing belt just to make sure I wasnt off on the belt. Reinstalled everything again and fired up the truck. It turned right over with no issues and the idle was perfect. So I must have been off a tooth or two. So when doing the timing belt on the 3.0 make sure all the marks line up. I thought I did but I was wrong.

TNRabbit

Sorry to hear you had to tear it all back apart (it's a PITA, I know) but I'm glad you found the problem--Happy Motoring!

89 v6

I too have the 3.0 and recently replaced the timing belt. I thought all was good and aligned. At cold startup no problems. Then I run it for a bit and I sometimes eventually get a low idle with timing off. Sounds pretty obvious, but the kicker is the sometimes part. Because sometimes when its good and warmed up she idles just fine. Was yours similar to this?

Brenjen

You might also have gotten a vacuum leak, especially if you forgot to plug the lines back to the power steering pump.

89 v6

What are those for?
I could've put them back in reverse.
I'll check.

Brenjen

They're for idling up the engine when putting the power steering pump under a load. It doesn't matter which side you put where, just so long as you have them hooked up or plugged off.

TNRabbit

You mentioned the cam sprocket was on backward; you know one goes ridge to the front and the other goes ridge to the back or prevent the belt from slipping off, right??!?

toyota_mdt_tech

Well, first off, that cam gear wasnt on backwards. They are opposite of each other to keep the belt from walking too far one way or the other. Usually, the drivers side will have the flange outward, pass side, it will be inward. As for your other symptoms, it sounds like late ignition timing. And if you didnt move the dist, it has to be a belt off one tooth.