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LH 2.4 problems

stoni said:
This is 99.9% the Injector Power Transistor T402 at the PCB, swap it and the ECU will be fine.
You can use a BDX53C DARLINGTON TRANSISTOR as replacement part.

Regards, Dirk
Click to expand...

Thanks, would be cool if i could fix it, would be a waste to throw away:)

I will see if i can find the transistor localy here.

Where on the pcb is the transistor?

-Henrik
 
Uberhenrik said:
I still have problems with hesitation, read the error codes today:

Ecu

2-3-2* Fuel trim (lambda control) too lean or too rich at idle

2-1-3 Throttle switch full load setting faulty or grounding short

Ezk

1-4-4* No load signal from fuel injection system


Would a "no load signal" cause major problems with ignition timing?
Click to expand...

Just thinking, could the 2-1-3 message (TPS broken) cause the 1-4-4? Will the ecu send a load signal if the input from the TPS is missing or faulty?

I am going to swap TPS later today, will see if thinks work better.
 
Have you verified that the TPS is adjusted properly and the connection is clean?
 
Uberhenrik said:
Where on the pcb is the transistor?
-Henrik
Click to expand...

Directly in front of the big red capacitor, the transistor is already removed:

0N973.jpg
 
klr142 said:
Have you verified that the TPS is adjusted properly and the connection is clean?
Click to expand...

I swapped out the tps today, adjusted it and the connection is also clean.

Resetted the ecu and ezk, i still get the 1-4-4 from ezk

1-4-4 = limp home mode, because of lack of load signal from Amm.

i also get 1-2-3 from ecu.

1-2-3* Signal missing to/from coolant temp. sensor

Does anyone have experience with the 1-4-4 error code?

Is this because of a faulty amm?
 
ok

Tried to find out what is wrong, i measured the load signal at the ezk, i found 350 mV between pin nr 8 and 20. (should be 370 @ warm idle) but as far as i can see the signal is not missing, so don't understand why it gives code 1-4-4

I also measured the AMM, found 2.3 volts @ idle between pin 1 and 3 as it should be. pin nr 1 had 0 ohm to ground. pin 5 had battery voltage when engine was turning.

Also measured ground on pin nr 20 on ezk, good 0 ohm ground.

Tried to clear the codes, these re appear:

ezk:
1-4-4* No load signal from fuel injection system

Ecu:

1-2-3* Signal missing to/from coolant temp. sensor (has not appeared the last time i cleared the codes today)
2-3-2* Fuel trim (lambda control) too lean or too rich at idle
2-1-2* Signal missing/faulty from oxygen sensor

I think the lambda related codes (232 and 212) are because of the ezk pulls a lot of timing making the AFR's in the exhaust wrong relative to the AFR in the cylinders. Further worsening the hesitation.

I think if i get rid of the 1-4-4 code and engine runs good again the lambda codes will disappear

Right now i don't know what else i can test, might be the AMM still is bad even if the measurements i took looked right.

Any ideas?
 
randomdude said:
do AMM values also apply to an '88 740 turbo?

the 1-2-3 code for ECT could be throwing off your AFR also, faulty ECTs can throw off afr.
Click to expand...

AMM values apply to an 88 740gl when it is converted to turbo and LH 2.4 :)

I am using an 007 amm from LH 2.2

Yes the ECT can throw of AFR, but i tested the resistance before i mounted it, also tested the voltage after it was mounted, values looked good.

Not sure why LH throws a code for ECT missing, have to take a closer look tomorrow.
 
orie said:
Everything i've ever been told/heard/read says you can't use a 007 on lh2.4 and you can't use a 016 on lh2.2. That might be part of your trouble right there.
Click to expand...

I was thinking about this, but i remember a buddy used a 007 when he first swapped to LH 2.4.

But might be mine is different, never know.

Does anyone have first hand experience with 007 AMM on LH 2.4?

I have always thought this was not a problem because of LH 2.4's ability to adapt to AMM's, that is why the 016 AMM's dont have the ajustment that the 007 has.
 
Uberhenrik said:
I have always thought this was not a problem because of LH 2.4's ability to adapt to AMM's, that is why the 016 AMM's dont have the ajustment that the 007 has.
Click to expand...

LH2.4 can't "adapt" to different AMMs. It adapts long term fuel trim based on O2 sensor feedback.

AMM devices are slightly more complex than other sensors because their response is logarithmic. Take a look at the Bosch spec: http://dl.dropbox.com/u/2074311/bosch_maf.pdf

Consider this: Compare lines #3 and #1. They both have nearly the same voltage range, but the #3 AMM can measure more air. The problem starts at the top of the scale. From 4 volts to 5 volts the #1 AMM increases from ~150kg/h to ~400kg/h. The same voltage range on #3 starts at ~300kg/h and ends at ~900kg/h!

Even if the fuel ECU does learn and trims out the differences above, it still reports the AMM values to the EZK without trim, because the fuel ECU only cares about fuel trim. And the EZK doesn't care what the fuel computer thinks of the AMM, it just assumes that the ECU has good information and goes by that. So then your timing can get wayyyyy off... Worst case is that your mismatched AMM is changing voltage output more quickly than the correct one would (because of the different curve) and timing is jumping all over the place.

TL;DR: AMMs suck, LH2.4 doesn't care about anything :-P, get the correct one or expect demons to posses your fuel injection system :twisted:
 
beepee said:
LH2.4 can't "adapt" to different AMMs. It adapts long term fuel trim based on O2 sensor feedback.

AMM devices are slightly more complex than other sensors because their response is logarithmic. Take a look at the Bosch spec: http://dl.dropbox.com/u/2074311/bosch_maf.pdf

Consider this: Compare lines #3 and #1. They both have nearly the same voltage range, but the #3 AMM can measure more air. The problem starts at the top of the scale. From 4 volts to 5 volts the #1 AMM increases from ~150kg/h to ~400kg/h. The same voltage range on #3 starts at ~300kg/h and ends at ~900kg/h!

Even if the fuel ECU does learn and trims out the differences above, it still reports the AMM values to the EZK without trim, because the fuel ECU only cares about fuel trim. And the EZK doesn't care what the fuel computer thinks of the AMM, it just assumes that the ECU has good information and goes by that. So then your timing can get wayyyyy off... Worst case is that your mismatched AMM is changing voltage output more quickly than the correct one would (because of the different curve) and timing is jumping all over the place.

TL;DR: AMMs suck, LH2.4 doesn't care about anything :-P, get the correct one or expect demons to posses your fuel injection system :twisted:
Click to expand...

Thanks for the input, i will try the 016 AMM

The wierd thing is that my friend could use a 007 AMM without any problems.
 
Noticed something when i was driving today, when the engine hesitates the RPM needle jumps all over the place.
Even at idle once today, the nedle was all over the place, even started to make popping sound in the intake. Then it went away.

It is totaly impossible to get over 3500 rpm at WOT, i can get it a little higher with just a little throttle.

Still looking for an AMM.
 
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