Weak Hot Start

Keep us posted.

 

Will do.

Sent some photos to a good friend who is an old school racer/mechanic he said the same cylinders 1, 3 and 4 are a little lean and cylinder 1 and cylinder 3 are leaner than 4.

I really hope ordering 4 new injectors fixes the lean condition. When I do the swap I will be pulling the positive cable on the battery in hopes of completely resetting the ECM.

If I can I will try and pull the O2 and the wide band O2 to see their condition.
The weather around here has just taken a nose dive so any additional work will be when things dry up.

 

The infrared camera shows no abnormal heat soaking on the coil packs after 30 minutes of sitting. Also the exhaust manifold looks consistently warm from cylinders 1 to cylinders 4 which means my EGT is fairly balanced.

 

Well chit.
So today was the beginning of some reckless testing. Seems I've got pre-ignition on all 4 cylinders or the system is running very lean. NGK spark plugs is having a look first thing in the morning.

Mini rant: Sadly this truck has been to the dealership and they keep saying all is well. I call BS but again no one at any Toyota dealership cares about their customers.

Rant off.

This may be the entire reason for my starting difficulty. Timing too advanced but why the truck won't throw a single code is beyond me. If the timing chain was loose besides the noise unloaded I would think the timing would go further retarded. My guess is tight valves. Damn shim under bucket design will make life absolutely hell to check valves and even reset them.

 

Straight from NGK. Combustion too lean.
Got a new wide band O2 and narrow band O2 to install when the weather cooperates. Still hunting down Xgauge codes for long term and short term fuel trims. What I have seems a bit off as the values fluctuate entirely too much. A/F ratio stays solid at 14.7 unless I blip the throttle then it swings to 13.6 for just a moment. Long term trim showed a bouncy -3 and Short term trim showed a bouncy 1. Never stayed solid. Ignition timing measurement is really off the wall. At WOT it was 43!

 

Well after looking at things even more I now have an official answer on the spark plugs. The plugs shoe slightly lean with a little ash deposits from oil burn off. All 4 cylinders are nearly equal.

Now back to hunting down the starting issue. More testing to come.

 

SPARK KNOCK!!! After starting and warming the engine for a few minutes I left to go pick up an oil filter for my significant others truck. When I throttled up to cross the road all it did was sputter and knock. So the fuel is definitely not making it to the cylinders under load. At idle it's fine and light throttle it's perfect but if you throttle up it knocks. The AFR went from 14.6 at idle to 13.9 then all of a sudden it started the knock which was at WOT and the AFR was 14.8. Damn thing went way lean.

Now I know I need a knock sensor (it should have tripped and flashed the CEL) and 4 new injectors. Freaking truck is a nightmare. Some days I really wish Toyota would program their ECM better.

 

so what are you thinking a bad fuel pump?

 

Not the fuel pump has plenty of output. 41-42 PSI at the fuel rail. Lean mix can be from plugged injectors or maverick air (non-metered air).

 

It sounds like advanced timing again by what you're describing... but I am not an engine expert, I just dabble in it. -Or- Leaking intake manifold. Have you tried the old Starter fluid test? Spray down small areas around the intake manifold seams while your engine is idling, your engine will rev when the spray gets sucked in through the air gap...

 

I've been into the truck so much it may be possible but unlikely that it has maverick air entering. I would rather use propane but no I haven't done the testing yet. Been a busy few days.

It could be timing but the plugs are on the lean side.

 

No maverick air entering any intake plumbing. So this time I think I got a break in have been looking for. I opened the oil cap and took a sniff and would you guess what it reeked of. GASOLINE IN MY OIL! This is the first time that has happened. 4 injectors on the way.

 

4 new injectors dropped in and an inline fuel filter tied in. The fuel filter may be temporary but during the process the fuel pipe coming from the tank and to the rubber line had the coating come off! Hopefully that will not effect sealing. Worse case scenario is buy a new rubber fuel line with a new o-ring that hasn't settled. ECM reset currently in progress. I will know more in an hour or so.

 

So far so good. Reconnected the battery and it fired up like a champ. We will see how things progress over time. I will try to update this thread after I see how the truck starts layer on tonight. Idle is smoother and part throttle acceleration has improved some. ECM is still in training mode and I need to get it on the interstate for the last if the fuel trim and table adjustments.

 

They did not leak until here recently. Before I would be running lean especially at any RPM above 3000. Plugs were white showing high combustion temps. Chances are the injectors were plugging and finally a pintle quit seating.
The giveaway that the injectors were leaking at the end was the oil smelled like my gas tank.

Still in the drive learn mode for the ECM. Extended idle, 0-45 light throttle, 0-45 moderate throttle, 0-45 heavy throttle, 45-25 coast, several transient acceleration runs at various speeds and all that remains is the highway speed runs constant at 55 and then at 70.

 

Well bad news. I must have gotten some bad injectors. Black smoke from the tail pipe.

 

Man! You can't catch a break!

 

No kidding. Just left five0 Motor sports a voice mail. Hopefully they respond with an answer. The injectors come with a 3 year warranty.

 

I'm going to unplug the battery for several hours and then again overnight and see if another reset helps. I've been told to unplug the positive cable and also the negative and tape them together causing them to short and drain the ECM.