7 replies to this topic

[Boomboy77]

Hi Guys, A friend of mine has just bought an SPi mini. He drove it from london to worthing and said it ran fine, now hes done some bodywork on it and tried to drive it again but now its VERY lethargic and wont rev passed 2500 without spitting back through the throttle body!!!
Ive check things like fuel pump running, ignition sparking and timing and thats ok, so I thought I would have a look at the spray from the injector, now when it gets to about 2500rpm it just cuts off, ie no fuel spray.........is this a duff injector???
We've tried another ecu but that made no difference, new fuel pump too.

Stumped!!! Any ideas?!?!?!?

[Big_Adam]

What you want to do is post in the INJECTION SPECIFIC board and look out for a nice chap by the name of Mini Sprocket

[Dan]

When you say bodywork, do you mean any welding? If it was welded were the proper steps takes to protect all the electronics?

[Sprocket]

Moved

[Major Burkenshaw]

Have you checked the vacuum tubes?

[Sprocket]

Yes indeed, if welding has been carried out on the body and the ECU was not removed before this, then the ECU may well be corrupt.

The fuel, Ignition and Volumetric Efficiency tables are electronicaly burned into the microchips, large transient currents generated by the welder flow through the cips and can corrupt or completely erase them, The ECU is then scrap.

This may not be your case however, as the engine runs to some degree It could also be a fault with any one of the Sensors especialy if the ECU ground point was not removed either.

Easiest way to diagnose this is by having a diagnostic done, or maybe swapping out the ECU for a known good one to see if the fault dissapears, if it doeasnt, your original ECU is fine, then the fault is with the sensors and the mechanics of the engine.

OR it could simply be a matter that something has been disturbed. Check that all the vac pipes and breather pipes are in good condition and fitted correctly. Remove the small vac lines and blow through to clear out. Check the spark distribution components as you would for any car.

Let us know if the ECU was removed and the ECU ground points were disconnected

[screech]

We've tried another ecu but that made no difference

...or maybe swapping out the ECU for a known good one to see if the fault dissapears, if it doeasnt, your original ECU is fine,

[Sprocket]

Whoopsie

Sorry dude, i missed that bit. LOL

It sounds like there is a blockage in the vac line to the ECU, its leaking or its come off entirely. Check these are good. I have seen the wrong type elbow used on the inlet manifold that caused the pipe to block itself off resulting in the symptoms you have.