[1991 fj80] Hard starting and rough idle help (1 Viewer)

[Yunfei Guo]

I got a starting and idling issue on my 91 land cruiser. It will start with no problem in the morning when the car is cold. It usually takes 6-8 cranks to start. It will took 15-16 cranks when the temperature is high. I can feel some misfire when the car is idling, but it will never stall. It runs great and I can't feel any power loss. I can push it to 4500rpm and drive up a hill fast.

New gas cap
New gas tank
New FPR
Cleaned MAF(maybe bad?)
New plugs
New fuel pump
New fuel filter
Fuel line checked by smoke test
Intake checked
New battery
New EFI relay
Vapor canister is not clogged(Not sure if is still working)

I do have a fuel leak when I top of the gas tank. The gas coming out of somewhere behind the rear axel. Not sure if it is related to the starting and idle problem.

 

[jonheld]

I don't see distributor cap/rotor and plug wires on your list.
When was the last time the valves were adjusted?
You don't have a MAF, you have an AFM. How did you clean it?

 

[Yunfei Guo]

I don't see distributor cap/rotor and plug wires on your list.
When was the last time the valves were adjusted?
You don't have a MAF, you have an AFM. How did you clean it?

Thanks for reply! I took the whole metal stuff out. spray MAF cleaner into it and put back in. It didn't change anything. The idle and starting sounds like air/fuel problem. When the engine starts, it sounds very weak (100-200rpms). It will be normal after around 2 seconds. I don't know when did the valves were adjusted.

 

[morganism]

Unbolt coil holding cage, clean hold down bolts and mounting nuts.

Run a seperate ground wire from ignitor to wheelwell ground. Check the seperate grounds to coil packs? Or is that just 100s. They added a seperate ground wire on that series.

Consistent problem on 60 and 62s

 

[jonheld]

Thanks for reply! I took the whole metal stuff out. spray MAF cleaner into it and put back in. It didn't change anything. The idle and starting sounds like air/fuel problem. When the engine starts, it sounds very weak (100-200rpms). It will be normal after around 2 seconds. I don't know when did the valves were adjusted.

Did you replace the cap and rotor?
Did you replace the plug wires?

The top end of the 3FE needs to be sealed to prevent unmetered air from entering the system. Any vacuum leak will cause a low/rough idle, though typically that won't cause hard starts.
Your cold start injector could be suspect as well as the temp sensor for the ECU, but I would look for the simple things first.

The 3FE wants a valve adjustment every 15K miles according to the FSM.

 

[jonheld]

Unbolt coil holding cage, clean hold down bolts and mounting nuts.

Run a seperate ground wire from ignitor to wheelwell ground. Check the seperate grounds to coil packs? Or is that just 100s. They added a seperate ground wire on that series.

Consistent problem on 60 and 62s

Boy, you love your ground wires, don't you.
This has never been an issue on any 80 Series AFAIK. Where are you getting this information from?

 

[Michael Hanson]

Hi, We've never added ground wires. Do as Jon says and look for vacuum leaks and a complete tune up. Mike

 

[Yunfei Guo]

Unbolt coil holding cage, clean hold down bolts and mounting nuts.

Run a seperate ground wire from ignitor to wheelwell ground. Check the seperate grounds to coil packs? Or is that just 100s. They added a seperate ground wire on that series.

Consistent problem on 60 and 62s

Thanks for reply. I don't think it will cause the problem. But I will check

 

[Yunfei Guo]

Did you replace the cap and rotor?
Did you replace the plug wires?

The top end of the 3FE needs to be sealed to prevent unmetered air from entering the system. Any vacuum leak will cause a low/rough idle, though typically that won't cause hard starts.
Your cold start injector could be suspect as well as the temp sensor for the ECU, but I would look for the simple things first.

The 3FE wants a valve adjustment every 15K miles according to the FSM.

The hard start rough idle might be 2 separate problems. I will bring it to a local mechanic to check for vacuum leaks first.

 

[Yunfei Guo]

Hi, We've never added ground wires. Do as Jon says and look for vacuum leaks and a complete tune up. Mike

Thanks!