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Injector problem: overfueling?

Chris Davis

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So, I have splashed out $100 on my twin 1r resistor pack, wired it in, and have a new problem. I have not got the car to idle yet, however, i did get it to start, with my fuel pump switched off? Before this, I noticed the engine had about 2mm of petrol in each bore, so replaced the spark plugs, and burnt it all off, with the fuel pump turned off. It cranked and cranked, then puff puff brim puff puff blah. running..... Dead. Then i switched the fuel pump on, and wouldnt start again, just cranked and cranked. opened it up, and was flooded. So, I then removed the plugs, and watched as the fuel pump primed with fuel pump on: no go, injectors holding the petrol. Sweet I then cranked the engine over with the fuel pump off, petrol everywhere. (maybe from the runners?) I checked the compression, 145psi all over. What I am wondering, is that if my ecu is grounding out the injectors, when i switch temporarily from on, to acc, then off, my injectors are momentarly open, releasing the pressure built up in the fuel rail? My injectors are connected to same relay as the coil- could this be a problem also? ie, power to injectors goes on at "on" I know that sounds confusing, but its because i am confused! Is it also possible that my injectors just want to overfuel, because my ballast is likely to be of less resistance than the car i grabbed the tune off? Thanks if you can help ashley, I did get it to run, so i am nearly there, Chris

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OK, chances are that the over fueling thing is probably because the engine has had a big flooding, possibly filling the manifold etc...  Here is what you have to do...  First thing is to make sure your fuel pump is wired and runs as it should.  It should run for a few seconds after key on, then stop.  Then start running when the engine is cranking and stay running while the engine is running.  the next thing is to prove that your injectors are actually doing what they should.  They should be off at key on except for maybe one pre-start prime pulse (not enough to flood the engine).  Injectors should deliver a short pulse for each revolution while cranking...   Reduce the value of the ECU's Master fuel number.  this will lean things up significantly.  Make sure all your grounds are properly terminated to the engine block.  Poor signal grounds have been known to cause injectors to stay on too long.  If your plugs are sooty, the  engine may not start on them.  You will need to make sure the engine is clean and dry of fuel, then put new clean plugs in.  Fouled plugs are one of the biggest causes of no-starts....

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