FZJ 80 unsolvable running lean condition please grab a beer help (1 Viewer)

[Viktor84]

Hello from Hungary
This is my first post I hope you find it interesting and I am desperate to get help with this issue
I am going to twist your minds here

Ive been reading posts from this site in the past 5 years since I own my 80
This is a very informative site and it helped me a lot to keep my cruiser in shape

I have a very strange problem that nobody can solve with this car in the past 2 years, I hope you could shed a light on the possible fault(s)

The car:

1997 FZJ 80 4500i, automatic A442F, OBDI (UK model RHD)
Yes that is 1997, only 1 oxygen sensor, no temp sensor @ EGR on inlet manifold, OBDI

The symptoms are:

- Lack of power (I am guessing that 30% of the power is missing) BAD
- High fuel consumption (I know these are thirsty but the average was 15l/100km, now 20l)
- Spark plugs are white, like you dip them in ash
- ECT sensor reads 95C degree @ idle, goes as high as 120C uphill (I have TOYOBDI android)
- Idle is not as smooth like you can place a coin on the edge on engine anymore
- NO fault codes in ECU at all
- I look as grumpy as Walther Matthau driving it coz it is not running right

Things that I replaced/renewed/fiddled with/cried over them:

- Ignition (Spark plugs 4 different makes, coil, leads 2 different makes, rotor arm and cap)
- Fuel filter
- Injectors cleaned, serviced, tested
- MAF replaced with 2nd hand and another from a known good running car
- TPS replaced with one from a known good running car
- IAC motor replaced with one from a known good running car
- Throttle body removed and cleaned
- Engine compression checked and all between 175-180psi
- EGR system removed, cleaned, inspected, modulator replaced with new blue sticker one (I also tried plugging the EGR since it gives no fault codes if you do it on this model as it does not have the sensor to tell the ECU you tampered with this)
- Engine wiring harness checked and I even replaced with an other harness to be sure it is right (this is RHD so the harness is routed away from the EGR pipe so this is not suffering from the melted wire syndrome)
- Engine ECU replaced just to be sure (1997 shouldt suffer from ECU fault but replaced anyways)
- All vacuum lines replaced everywhere
- All gaskets replaced on exhaust, inlet manifold
- PCV, grommet, hose replaced
- Checked manifold for cracks with cold start spray everywhere and visually when it was apart
- Intake rubber pipe replaced from MAF to throttle body
- Ignition timing checked in service mode, Ive played with it a lot, no change
- Cat converter checked deemed to be ok but replaced with a straight pipe just in case, no difference(it only has 1 oxygen sensor from factory before the cat so no matter if you remove them)
- Air filter of course replaced
- Radiator, hoses, thermostat, water pump replaced
- Knock sensors, both replaced
- Engine temperature sensor replaced (the old one tested ok for resistance but just in case)
- Alternator serviced with new brushes and bearings
- My credit card limit
- A divorce (we reunited)

Am I missing anything??

Please give me an idea, anything that you could think of, this car is driving me crazy, after all that Ive done it is still not right

Thank you

 

[whitrzac]

Pictures of spark plugs after running?
Fuel preasure test?
Replace fuel pump?

 

[ccslider]

Hello from Hungary
This is my first post I hope you find it interesting and I am desperate to get help with this issue
I am going to twist your minds here

Ive been reading posts from this site in the past 5 years since I own my 80
This is a very informative site and it helped me a lot to keep my cruiser in shape

I have a very strange problem that nobody can solve with this car in the past 2 years, I hope you could shed a light on the possible fault(s)

The car:

1997 FZJ 80 4500i, automatic A442F, OBDI (UK model RHD)
Yes that is 1997, only 1 oxygen sensor, no temp sensor @ EGR on inlet manifold, OBDI

The symptoms are:

- Lack of power (I am guessing that 30% of the power is missing) BAD
- High fuel consumption (I know these are thirsty but the average was 15l/100km, now 20l)
- Spark plugs are white, like you dip them in ash
- ECT sensor reads 95C degree @ idle, goes as high as 120C uphill (I have TOYOBDI android)
- Idle is not as smooth like you can place a coin on the edge on engine anymore
- NO fault codes in ECU at all
- I look as grumpy as Walther Matthau driving it coz it is not running right

Things that I replaced/renewed/fiddled with/cried over them:

- Ignition (Spark plugs 4 different makes, coil, leads 2 different makes, rotor arm and cap)
- Fuel filter
- Injectors cleaned, serviced, tested
- MAF replaced with 2nd hand and another from a known good running car
- TPS replaced with one from a known good running car
- IAC motor replaced with one from a known good running car
- Throttle body removed and cleaned
- Engine compression checked and all between 175-180psi
- EGR system removed, cleaned, inspected, modulator replaced with new blue sticker one (I also tried plugging the EGR since it gives no fault codes if you do it on this model as it does not have the sensor to tell the ECU you tampered with this)
- Engine wiring harness checked and I even replaced with an other harness to be sure it is right (this is RHD so the harness is routed away from the EGR pipe so this is not suffering from the melted wire syndrome)
- Engine ECU replaced just to be sure (1997 shouldt suffer from ECU fault but replaced anyways)
- All vacuum lines replaced everywhere
- All gaskets replaced on exhaust, inlet manifold
- PCV, grommet, hose replaced
- Checked manifold for cracks with cold start spray everywhere and visually when it was apart
- Intake rubber pipe replaced from MAF to throttle body
- Ignition timing checked in service mode, Ive played with it a lot, no change
- Cat converter checked deemed to be ok but replaced with a straight pipe just in case, no difference(it only has 1 oxygen sensor from factory before the cat so no matter if you remove them)
- Air filter of course replaced
- Radiator, hoses, thermostat, water pump replaced
- Knock sensors, both replaced
- Engine temperature sensor replaced (the old one tested ok for resistance but just in case)
- Alternator serviced with new brushes and bearings
- My credit card limit
- A divorce (we reunited)

Am I missing anything??

Please give me an idea, anything that you could think of, this car is driving me crazy, after all that Ive done it is still not right

Thank you

hahahahaha nice list!

It sounds like you did alot.
Can you post pictures of the spark plugs?
Doesn't make sense that its using more fuel and running lean.
Did you perform a compression check?

 

[Viktor84]

Pictures of spark plugs after running?
Fuel preasure test?
Replace fuel pump?

 

[Viktor84]

Fuel pump hasnt been replaced and fuel pressure not checked
Reason why is that the car had LPG system fitted and it did not make any difference if I was running on petrol or LPG
The system is now removed like it was never fitted, engine wiring harness replaced( just in case if there was a bad soldering)
I drove the last 20k miles on petrol only with 2 different sets of valves and all turned white like this.

 

[Viktor84]

hahahahaha nice list!

It sounds like you did alot.
Can you post pictures of the spark plugs?
Doesn't make sense that its using more fuel and running lean.
Did you perform a compression check?

Compression is fine, 175-180psi on all cylinders

 

[landtank]

O2 sensor

 

[Viktor84]

O2 sensor

I missed this from my list
I has been replaced 2times with different makes
Last one is a Denso

Strange thing is I dont fell difference in performance with a disconnected sensor

 

[whitrzac]

Plugs look OK to me... Maybe gaped a bit too much.

 

[ajax1]

Injectors all plugged in and running right? My buddies was running on 5 cyl, cause one plug wasn’t seated to injector so not firing

 

[Bear80]

Was the compression test accompanied by a leak down test? I'm thinking valve issue, maybe slight sealing issue or burnt or even head gasket. What's the pressure like in the crank case?

When was the valves last adjusted?

 

[Viktor84]

Thanks for the quick replies

We just finished the head gasket job yesterday, it was suspected after the blue liquid turned yellow like in the Scotty Kilmer test(strange he was using an FZJ80 demonstrating the test)
Anyways the car is back together and there is no change in performance... it still drives crap

The head was skimmed, pressure tested, valve clearances set and they fitted hardened valve seats so it can take LPG without closing up on the gaps of the exhaust side of the valves

I am thinking some sort of an electrical issue. Like a ground missing or something loose
How do you test components are getting the right power and ground like the MAF, where would you start?
Would it help if I upload readings of TOYOBDI?

 

[whitrzac]

Can it graph just the o2 sensor voltage?

It says it's reading rich, but I can't make out the voltages on the graph.


I had the oposit problem with my o2 sensor where it was reading wrong and adding way to much fuel.



You could try uplugging the o2 sensor. Reseting the ecu and driving around for a bit to see if it's better. It won't be perfect but it will be close.

 

[whitrzac]

Ignition timing seems off too.

 

[ThomasMore66]

Got the wife back...maxed the credit card...

 

[BILT4ME]

That thing is running lean as hell!

The exhaust valves are WHITE! You're lucky you didn't actually burn a valve!

Things that will cause it to run lean:
Timing (Must be PROPERLY set)
O2 sensor
Knock Sensor
Temp Sensor
Low fuel pressure
Leaking air (Unmetered air entering the system)

Since you have changed all these sensors, I would look at the Unmetered Air.
Oil cap
Spark Plug Tube Seals
PCV Valve system
Vacuum brake booster check valve and booster
All vacuum hoses
EGR Valve
PAIR unit? (If equipped)
Intake air hose cracked
AFM/VAF/MAF unit. Does this have the MAF of the US97 model or the AFM or the US94 model? Check to make sure the wiring harness on this item didn't get yanked and broken.
Intake manifold leak or plug missing
Valve gasket cover leak

How was the LPG system installed? You said it was 100% removed. Did ALL ports get properly plugged?

 

[Bear80]

4.3 negative on the timing. Am I understanding that correctly?

That type of timing will cause it to run lean.

Should be 5-15 positive or advanced. Either the computer is retarding the timing or it is set incorrectly.

If the computer is retarding the timing look for a faulty input from a sensor such as the knock or temperature sensor.

 

[baldilocks]

Is there a possibility that oxygen is entering the unstock exhaust system somewhere from the head back causing the O2 sensor to erroneously read a rich condition and then lean the fuel injectors out?

 

[BILT4ME]

Is there a possibility that oxygen is entering the unstock exhaust system somewhere from the head back causing the O2 sensor to erroneously read a rich condition

If there is a high oxygen reading in the exhaust, it will cause the fuel mix to go RICH, not lean. So, not an exhaust leak allowing O2 in.

It would have to be an unmetered air in on the INTAKE side of things.

 

[ZackR]

Ignition timing looks way off.... impressive list, this is what we like to see from first time posters.

Grab a timing light and set to factory specs(3˚), then bump it up a little (7-9˚) and see how it runs.