Help. 3RZ problems...

[toyotsurf]

Hi Daniel.
Good to hear from someone at this side of the Atlantic, even if we are separated by the North Sea !!!
The only reason I will be pulling the starter is that it will make swapping the knock sensor easier. I have owned her for 15 years or so and she has been a fantastic little car and not a minute's trouble until earlier this year. Even so she fires up first turn of the key every time and has NEVER let me down and got me where I needed to go through deep snow, deep water ,hot summers . I towed trailers with 3 tons plus at 70 mph. I want to get to the bottom of it and keep her another 15 years. The 3 RZ is a good little motor and I prefer it to the KD or KZ powerplants. The 1 KZTE is torquey and in fairness if not overheated or abused is reliable. I would not be worried about heads but like all 4 cylinder diesels of this capacity it vibrates which at idle speed is annoying at times. The fuel economy is poor too, my RZ is better on fuel than any KZ I have owned.

 

[eurasiaoverland]

Hi Daniel.
Good to hear from someone at this side of the Atlantic, even if we are separated by the North Sea !!!
The only reason I will be pulling the starter is that it will make swapping the knock sensor easier. I have owned her for 15 years or so and she has been a fantastic little car and not a minute's trouble until earlier this year. Even so she fires up first turn of the key every time and has NEVER let me down and got me where I needed to go through deep snow, deep water ,hot summers . I towed trailers with 3 tons plus at 70 mph. I want to get to the bottom of it and keep her another 15 years. The 3 RZ is a good little motor and I prefer it to the KD or KZ powerplants. The 1 KZTE is torquey and in fairness if not overheated or abused is reliable. I would not be worried about heads but like all 4 cylinder diesels of this capacity it vibrates which at idle speed is annoying at times. The fuel economy is poor too, my RZ is better on fuel than any KZ I have owned.

Hi Richard

Thanks for the reply, I've sent you a PM

As said, I am a big diesel fan, but when I come to buy another it will have to be a six cylinder!

Cheers Daniel

 

[toyotsurf]

Well, fitted the new O2 sensor and it definitely runs better. CEL lamp comes on randomly , it came on for the first time today since before Christmas. I think I need to buy a new knock sensor, and an idle control valve. I might even buy a new AFM while I am at it. The Toyota stealership in the UK will rob me for these items but does anybody on the forum have an idea how much they cost at Toyota dealers in the States ?

 

[triangles]

I'd buy those at an autoparts store. Forget getting raped by the stealership. A quick search at advanced autoparts website says $130-$160 for the knock sensor and $200 for the OEM one. Idle air control valve is $225-$267. On Rockauto.com (wonder if they'd ship to you) it was $83 to $125 for the knock sensor and $115 to $165 for an IAV.

 

[eurasiaoverland]

Well, fitted the new O2 sensor and it definitely runs better. CEL lamp comes on randomly , it came on for the first time today since before Christmas. I think I need to buy a new knock sensor, and an idle control valve. I might even buy a new AFM while I am at it. The Toyota stealership in the UK will rob me for these items but does anybody on the forum have an idea how much they cost at Toyota dealers in the States ?

Hi Richard

Took me a while to find this thread again, I hope you have your problems fixed!

As for me, last weekend I finished my rebuild. It was way more than I ever expected, as the previous owner had really bodged and neglected the truck. here is a rundown of what I did:

Block bored +0.50 mm
4x genuine +0.50 mm pistons and rings
Crank ground down to -0.25 mm, new bearings
New balance shafts
New balance shaft bearings pressed into block
New genuine cylinder head
16x new genuine valves

New genuine IACV (idle air control valve)
New genuine thermostat

Tested O2, air and coolant temperature sensors, all ok.

Cleaned the MAF with MAF cleaner spray (use a magnifying glass to inspect the wire across the contacts on the sensor)

Injectors ultrasonically cleaned and tested

I've only run it for about 15 minutes as there are a couple of other things I need to do before driving the vehicle, but it was very smooth and sounded great. The hot starting problem is gone, as is the hesitation on acceleration, though this is all idling. It's not the fastest engine to pick up but I guess this is normal with such a large (for a petrol) flywheel.

Did you get to the bottom of your problems?

If you buy genuine parts, I strongly recommend www.amayama.com The only time I would go to a dealer is for stuff too large to be shipped over

Best wishes

EO

 

[nsahk]

Hi toyotasurf and eurasiaoverland. Did either of you ever solve the problems you had - hesitation at low engine speeds? I have the same issue. Have been trying to fix it for a while and wonder if it's a knock sensor issue retarding the timing.

 

[Surf-Petrol-96]

Similar issue solved - knock sensor wire

I had a similar issue where the RZN185 would drive fine until accelerating heavily or uphill. The check engine light came on and at the same time there was a noticeable decrease in power. The issue was the single wire to the knock sensor had come out of the plug and could be pushed back in while the plug is attached. Albeit after removing the intake manifold to get to it. Thank you for steering me to the solution.