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[TheBoy]

Mrs TB's bro has a problem with his Veccy...

Car: Vectra-B
MY: 2001
Engine: Z18XE
ECU: Simtec 71
Symptoms: None beyond EML

EML comes on, pretty much every journey.  All codes cleared, the one that came back on on test run is:

P1555 - TPS not plausible with Engine Load

(P1550 and P1525, along with an immobiliser one were all in the ECU before I cleared it).

Live data on a run saw APP and TPS acting normally, even when EML came on.  Only thing that looked a little odd was the Engine Load, which seemed to read FULL LOAD most of the time the throttle wasn't at idle.  Occasional PARTIAL LOAD, and obviously IDLE on overrun.


The overriding question is, what is the fix - without spending too much, as he wants to sell, as he has already bought another car.  For my own benefit, how is engine load calculated.


There is ever such a slight miss at idle, and I'm told it misses at high RPM, so told him to change the plugs in first instance - knowing him, eas the car has done 79k, I bet its on originals, assuming quads fitted .  But I don't think thats the cause of the EML?

[Marks DTM Calib]

What was the MAF reading looking like?

[TheBoy]

What was the MAF reading looking like?

valid when I checked, although I spent more time looking at APP and TPS. 11kg at idle

[deviator]

First things first....
Check breathers
Remove TB (possible inlet, if you feel like it)
Clean everything out, there is a pinhole in the tb that often gets blocked with gunk.
If you are doing a cleaning sesssion, treat it to a new TB and/or inlet gasket. The TB one was 49p or something stupid from VX, althought the inlet is like £7! Rob-dogs.

Couple of other notes.....
The 1.8's have a common fault with earth to ECU and MAF, there is a fix involving fitting additional earths. Although this doesn't sound like you problem.
I've seen TPS fault come on when the timing was out by one tooth. TPS code was the only code shown. This took me ages to work out what was wrong!
Is it defo the z18xe? What colour plastic cover do you have on top of the engine?


EDIT

OK the other 2 codes you mention refer to the electronic throttle. If your FCR supports it, check both pedal potentiometers. One should go up in volts as the other goes down whilst depressing the pedal. This is a safety feature to stop the pedal from locking in full throttle. The last time I had problems with a pedal, I swapped the pedal, made no difference. In the end it was the previous owner (bought as none runner) who'd tried to fit the plugs to the ecu, only to bend 10 pins.

[TheBoy]

What was the MAF reading looking like?

Laying awake last night, I think its worth paying closer attention to MAF.  Hopefully will see it again this week.

Thanks

[TheBoy]

I've seen TPS fault come on when the timing was out by one tooth. TPS code was the only code shown. This took me ages to work out what was wrong!

Happened shortly after cat was replaced. Yes, I know.  I was expecting the fault to be a cat code.

Is it defo the z18xe? What colour plastic cover do you have on top of the engine?

silver

OK the other 2 codes you mention refer to the electronic throttle. If your FCR supports it, check both pedal potentiometers. One should go up in volts as the other goes down whilst depressing the pedal. This is a safety feature to stop the pedal from locking in full throttle. The last time I had problems with a pedal, I swapped the pedal, made no difference. In the end it was the previous owner (bought as none runner) who'd tried to fit the plugs to the ecu, only to bend 10 pins.

Yeah, I know about he twin pot setup on both pedal and TB, and given the fault code, it was these I was paying most attention to. Reader is a Tech2, so can read pretty much anything.