90 4runner v6 auto

Had the engine rebuilt a month ago or so, they didn't replace the knock sensor pigtail at the time, threw a code 52 when they were done with it, had them replace the knock sensor and pigtail due to time, still had a code 52. They wanted to replace the ECU and other stuff that would cost a lot and probably not fix anything, so I took it home to figure it out. I was pretty frustrated by the shop and how long it took them to do a bad job (month when they quoted a week and a half).

Did some troubleshooting, mounted my old sensor to the lift hook to see if it was the harness to the ECU or ECU. Also checked continuity, all showed fine and the code 52 went away when I put the sensor on the lift handle, indicating the knock sensor they replaced it with was a cheap knock off that didn't work.

Talked to the shop about them replacing it and they wanted to charge for labor again, so I decided to do it myself, also, didn't really trust them with all the missing bolts when they were done.

Just finished it today, no codes being thrown, but I'm getting a bad knock or misfire, don't really know the difference. It'll die as well. The idle sounds fine aside from the knock, and then when it dies.

• I marked the timing belt and I'm pretty sure I didn't move it
• new gaskets and stuff
• not missing any bolts or washers, so I'm pretty sure none dropped in the manifold
• timing in 10*

not sure what else it could be? would any rtv shavings be an issue if they fell into the manifold?

any suggestions?

thanks

it was running fine when I had the knock sensor mounted to the lift hook for a week or 2

 

Vacuum leak? Unmetered air can do crazy things.

Cams and crank were positioned correctly when the timing belt went back on? T-belt tensioner in place?

 

I don't think it's a vacuum leak, I'll recheck all the lines tomorrow. I didn't remove the t belt, just the idler pully.

 

Also, check the air intake tube and around the throttle body if you had any of that loose.

 

Intake tube going into throttle body has a crack under the clamp on the intake, taped it up, still have the problem.

Removed the plugs and blew compressed air in the cylinders, didn't hear anything move around


Rechecked all my vacuum lines, good

No codes

Timing belt might be off a hair, driver side crankshaft looks like the marks are lIke a tooth or a half off at TDC maybe.

 

Pretty sure it's fixed, sound went away last night. Not really sure what it was, could've been a combination of things, such as me putting some weight on the valve covers getting the intake manifold off? I ended up replacing the spark plug wires too since the place that did the rebuild had the wires resting on the heat shield or something, a hole burned through one of the wires.

Anyways, if you're in AZ, I do not recommended going to Discount Engine off the 60 and country club. Worse decision I have made in a while.

 

Glad you got 'er fixed!