Help. 3RZ problems...

[toyotsurf]

Hi all.
I own a 1998 Toyota Surf ( 4 Runner) with the 4 cylinder 3RZ-FE engine.
Recently I fitted a new cylinder head, 16 new valves, all new gaskets etc.
The engine starts and idles beautifully, like new but when you are driving her she bogs down under normal acceleration conditions and almost dies but if you put the pedal to the boards she will then take off like a scalded cat, so to speak. After 10 minutes of driving the CEL light will illuminate, at this point it actually drives better !!! She will still do 90 mph with the CEL on so there cannot be much wrong with her but the fuel economy is awful, a big block V8 would be more economical than she is at the moment. I have owned her for 14 years and she has been a terrific little motor but at the moment she is driving me mad. Can anyone help, has anyone else had the same problem ?

 

[IBallEngineer]

Hi all.
I own a 1998 Toyota Surf ( 4 Runner) with the 4 cylinder 3RZ-FE engine.
Recently I fitted a new cylinder head, 16 new valves, all new gaskets etc.
The engine starts and idles beautifully, like new but when you are driving her she bogs down under normal acceleration conditions and almost dies but if you put the pedal to the boards she will then take off like a scalded cat, so to speak. After 10 minutes of driving the CEL light will illuminate, at this point it actually drives better !!! She will still do 90 mph with the CEL on so there cannot be much wrong with her but the fuel economy is awful, a big block V8 would be more economical than she is at the moment. I have owned her for 14 years and she has been a terrific little motor but at the moment she is driving me mad. Can anyone help, has anyone else had the same problem ?

Before anyone can help, what DTC is being set?

 

[toyotsurf]

Hi there.
My obd reader will not communicate with her. How do I read the flash codes ?

 

[toyotsurf]

Hi there.
The CEL code flashed up as 52 which is supposedly a Knock sensor code.
I just cannot figure out how it has malfunctioned by changing the cylinder head.
Unless the wiring harness got damaged somehow ???

 

[toyotsurf]

Has anyone else experienced this problem before ???

 

[IBallEngineer]

Hi there.
The CEL code flashed up as 52 which is supposedly a Knock sensor code.
I just cannot figure out how it has malfunctioned by changing the cylinder head.
Unless the wiring harness got damaged somehow ???

I realize you are in the UK, we don't have a code 52, knock sensor codes are PO325 or PO330.

In either case I'd start looking at the wiring, otherwise you need a scan tool that works to get real data.

:snacker:

 

[toyotsurf]

Thanks. I have a Snap On Ultra scan tool but for the life of me I cannot get it to communicate with the old girl. What year did Toyota go on to proper OBD codes from the old crude flash codes. My truck was manufactured in 1998, did US market products have modern OBD codes at this time ?

 

[IBallEngineer]

Thanks. I have a Snap On Ultra scan tool but for the life of me I cannot get it to communicate with the old girl. What year did Toyota go on to proper OBD codes from the old crude flash codes. My truck was manufactured in 1998, did US market products have modern OBD codes at this time ?

OBD II became the standard in 96, but earlier vehicles should still have two way communication available.

 

[jonorok]

Yeah, all third gen 4runners, 96 and on, should be OBD II driven.

 

[toyotsurf]

I will phone Snap On tomorrow. They have a Tech line and hopefully they will point me in the right direction.... Do US market trucks have a 16 pin standard obd plug or do you guys use the under bonnet diagnosis socket under the bonnet or rather hood ?

 

[jeremyc74]

This sounds like a bad sensor to me (or the wiring between the sensor and ECU). I think the ECU is getting bad data and is trying to deal with it, and then when it finally gets bad enough it gives up and switches over to a safety mode, and that's when you get the CEL and it starts running better.

You really need to figure out what code is being set, because that's likely to point you directly to the issue. I'd test the TPS first thing, just because it's easy to do. IIRC on the 22RE motors the TPS is adjustable, and can cause problems if it's not adjusted properly.

 

[toyotsurf]

TPS. Do you think the best way to try that could be to take it fully one way, road test then try the opposite extreme to see if there is any improvement. It is definitely adjustable on my truck.

 

[toyotsurf]

I think you are right about the sensor/ wiring thing but I will try the TPS tomorrow. Thank you for your help. It is most appreciated.

 

[Paperjam]

This is a classic knock sensor issue.

If your knock sensor is not connected or functioning the engine will retard timing. This gives you a doggy engine and poor fuel economy. Check your wiring as you just did a bunch of work! It's right above the fuel filter on the intake side of the engine. The PCM uses the knock sensor to advance timing and give you proper ignition timing.

Running better after setting a code suggests that the PCM is reverting to a base timing

I swapped my harness during my manual swap and forgot to hook this little guy up, I had no power at all, and my economy would have been shit if I hadn't found the problem right away.

This is the FIRST place I would go, it's a one wire sensor, find the pin on the PCM connector (disconnect the connector from the computer) disconnect the knock sensor wire and check its resistance using a multimeter. It should be less than 1 ohm. Also check that the pin connector isn't damaged. If those are both ok, replace the sensor.

Also clean your MAF, it might not have anything to do with this, but it takes 5 mins and can give you a world of benefit.

 

[jeremyc74]

This is a classic knock sensor issue.

If your knock sensor is not connected or functioning the engine will retard timing. This gives you a doggy engine and poor fuel economy. Check your wiring as you just did a bunch of work! It's right above the fuel filter on the intake side of the engine. The PCM uses the knock sensor to advance timing and give you proper ignition timing.

Running better after setting a code suggests that the PCM is reverting to a base timing

.

Sounds very reasonable to me.

 

[jeremyc74]

I think you are right about the sensor/ wiring thing but I will try the TPS tomorrow. Thank you for your help. It is most appreciated.

There's an adjustment procedure for it somewhere, but I can't find it.

Anyone have access to the service manual for this?

 

[toyotsurf]

Thanks guys. I have been moving the PCM back and forth but maybe I need to disconnect the battery after each adjustment to reset the ECU ?
I am pleased to hear that the knock sensor has only one wire because that might make the fix easier. I have no work for the next 3 days being Easter so if I can find a pinout diagram I could have a look at the old girl this weekend. Is the knock sensor shared with any other Toyota models because a 4 cylinder petrol (Gasoline ) 4runner is a rarity in England. Most of them are Dirty Diesels ! Maybe I could then make an impromptu loom and strap or clamp another knock sensor to the engine block and see how she performs.
Thanks again for the help guys.

 

[Paperjam]

A knock sensor is a very simple sensor. Google piezoelectric, it generates a voltage when it "hears" knock.

Why build a harness when you could just check the one you have? No point in doing all the work to rig up something when you could spend the time checking the one you have. Do you have a digital multimeter handy?

And the sensor should be cheap, just get yourself a new one.

 

[toyotsurf]

You are right Paperjam. I am just making myself work !!!! I just need to find a pinout diagram for the ECU to start probing.

Does anyone know where I can find one

 

[Paperjam]

I use a program at work called alldata, it's professional grade for all makes and models and will have this information. You may be able to find it pirated online, not like I would suggest doing anything like that

You should be able to purchase a factory service manual on eBay or the like if you only want information on this model specifically.