spoilt_rs

Hi all,

Can anyone recommend me a ECU test and repair centre to take a look over my L8?
I cannot get my car to start, and am not seeing the readings i would expect from the tps, and also dont beleive it is running the fuel pump either.

Cheers.

RS500/364

You dont make it clear what cant see the readings

spoilt_rs

when using a voltmeter on pins 1 and 17 of the ecu plug, i see readings between 0 and 0.3 volts, i beleive i should be seeing more like 4.5 volts when throttle fully open. I have had electrical problems before now, with a different chip i was running. it was an MSD chip, and i had damaged a leg on the lower piggyback module during install, and persumed this was giving me problems.
I now have a brand new ahmed chip with new pectel babyboard, yet i appear to still be having issues. I would just like to have it checked over to make sure the ECU isnt a dud.

Cheers.

cozmeister

iTrader: (1)

You won't get any reading if you try reading the voltage of the TPS while the engine's running - in fact, it'll probably stall and you might pop something...

You can however get a reading from it with the ignition at II with the engine off so you can get see if there are any permanent flat spots. Also make sure you're counting pins from the correct side or you'll measure or short something else!

Also, pin 1 is earth for the ECU which operates at 12 volts, not earth for the TPS which only uses 5 volts! The TPS takes a 5 volt feed from pin 30, which goes through the TPS and returns to the ECU on pin 17, and is grounded on pin 11. So if anything you should be measuring the voltage 30 and 17 to get the output of the sensor.

The L8 will use the lowest stable voltage as its base throttle setting, usually around 0.3v and open linearly to about 4.5v at 82degrees throttle angle (wide open).

The engine will run (and start) without the TPS connected, but there'll be no enrichment when you open the throttle.

Best idea is to get someone with the right diagnostic equipment to plug that in as you could easily pop something accidentally - the proper kit will also work while the engines running as some problems won't become apparent unless you're actually driving.

spoilt_rs

Cheers for the replys.
I havnt been measuring the voltage with the engine running,
but looks like I may be using the incorrect pins. The pins are numbered,
so it's easy to make sure you check the right ones.
I don't have the option to take it anywhere is it won't fire up.
I am going to send the ecu to automatec in Devon for a check.

Cheers

RS SHAUN

iTrader: (24)

ive used automatec before, excellent service!
cheers shaun

cozmeister

iTrader: (1)

I realised my mistake on the way home, now PF's running like a 1 legged horse.

You need to measure the output from the TPS to the TPS earth, ie, pin 17 to pin 11. If the voltage drops to 0 or jumps to 5, the TPS is broken.