My car is being very strange of late. I have just fitted a TD05 18g and a Newage TMIC. Upon going down to have it remapped last week, it was acting very strange under mapping conditions. The revs were quite irratic at idle, there was no reading from the Knock Sensor on the ECU (although this was still plugged in and looked fine), upon attempting to upload a map onto the ECU, it would not procede as apparently there was not enough battery voltage. When we finally got a map uploaded and did a power run, the Battery voltage graph was spiking massively, ranging from 10-14 volts (when it usually is a constant 12v). Also, after a period of time messing around trying to map it, the car started hesitating slightly when lightly accelarating off.

With the fuelling sorted, we eventually binned it off to try and rectify the fault. I actually had both the drivers headlight and sidelight out, so the mapper was asuming it was an electrical connector/earth somewhere, which was causing the lights not to work, and thus the car to act strange during mapping.

So I went away with the intention of finding this fault, sorting it and going back down to have ther boost upped! The light problem turned out to be both bulbs in the headlight and sidelight were blown, so Ive replaced them and all was good.

Now, since leaving there the other night, the car was running completely fine, boosting properly, and not doing any of the things it was doing during mapping.

Although last night, I came out of work and set off home. It instantly felt strange under accelaration, as if it was kinda hesitating. I thought it was just because the engine was cold, but as it got warmer the Check Engine light came on.

Basically, as I go to accelarate - either lightly or giving it a bit more - it seems to hesitate/jump a bit, enough to notice. Its very strange, as it does it when cold; but the CEL doesn't come on until the engine has warmed up. It is virtually the same as it was doing during mapping.

Has anyone any ideas?? I know, I should be asking the mapper all this; but I feel as though I have hassled/pestered him loads within the past few weeks regarding numerous things, so I just thought id see if anyone else had ever experienced similar symptoms?

Many thanks, and sorry for the essay

Steve0

 

battery terminals lose, earths on the engine / ecu need replacing / cleaning?

 

Have you checked your alternator for proper output voltage?

 

Thanks for the quick responces guys.

I havent checked either; but will. How do you check the alternator??

 

get a multimeter and put it accross the terminals.

start engine and check reading, should be 13.8-14.4v
apply lots of load, heated rear window, heaters, lights etc.
should stay the same.

 

Right, cheers.

Anyone else got any suggestions??