five4X4s

Hey Everyone!

Yes, it's unfortunate, but this is another "not starting" problem. Just some background:
- in 2016 I did the knock sensor and head gasket change - I had the heads re-conditioned as well as numerous other parts added or conditioned a list is as follows: new spark plugs, new belts, new spark wires, new rotor and cap, replaced intake (old one had a crack), new OEM knock sensor, new pigtail, replaced airflow filter, new battery, timing is dialed in (just checked it before hoping on the thread), fuel filter is good.

Long story short I put it all back together and it won't start. It cranks over but never starts.

I've taken it to 4 highly recommended Toyota mechanics throughout the LA area and they all get it back to me scratching their heads saying they have no idea what's wrong with it. I'm at my wits end. It's been two years and I can't figure it out. Hoping some people here may have had a similar issue... Here's throwing up a prayer you guys do!

scope103

First, how do you know it has spark/fuel/air?

By "crank over, " I assume you mean it NEVER fires.

Second, have you checked compression? Easy, cheap, and low compression can prevent starting. Low compression CAN be caused by mis-set valve timing.

Third, are you sure the distributor is not 180° out? Timing will look good, but the plugs will be firing at the top of the exhaust stroke instead of the compression stroke. To check, you'll need to remove a valve cover or the upper timing cover to determine (from the valves or the cam sprocket) when the TDC you set is at the top of the compression stroke on #1. Does the distributor rotor point about 10° past the #1 post?

five4X4s

Thank you for your reply! I'll answer your questions in order. I have taken each spark plug off then cranked it over to test for spark at each plug. Each plug is getting spark. There is fuel at the fuel filter intake and exit hoses. Also, the cold start injector "spews" fuel when tested. The MAS was checked and tested on another 4Runner and worked fine. Also, there are no obstructions in the air intake hose to the throttle body. When I initially (after letting it sit for some time) "crank over" the engine, it begins to fire but never completely starts. After that it just cranks without any ignition whatsoever. The compression is spot on. Prior to replacing the knock sensor, I had just had all of the heads resurfaced and head gaskets replaced. If I'm not mistaken, the valves were adjusted at that point.

You may have something on the timing issue. Although, just prior to sending the post, I tested the #1 cylinder's TDC in conjunction with the position of the rotor. It appears to be spot on the #1 distributor post but if not exact, I'm certain it is not enough to prevent the engine from starting. Were you wondering if the distributor gears were off by a tooth??

akwheeler

With a 4 stroke engine each piston will be at top dead center twice for each cycle, once at the top of the exhaust stroke and once at the top of the compression stroke, so even if you set the distributor at TDC you still haven't guaranteed that it is right. That is what everyone is talking about when they say your dizzy is 180 out, one full turn of the crank shaft will spin the distributor 1/2 a turn.

You also verified fuel flow to the fuel rail, but you haven't verified that the injectors are shooting it into the intake runners.

try a shot of starting fluid, if it fires then you know you have a fuel supply issue, if it doesn't you either have a spark issue (not enough or at the wrong time), no compression, or it's totally flooded.