mad_pete Posted February 7, 2008 Share Posted February 7, 2008 Just stuck a 4.2 V8 in my 90. It will start but only on a key flick. If it goes on to crank it won;t start. So its key flick or nothing So it's like the crank is drawing too much power and stopping something working. Fuel pump seems the same, and I think I get spark on crank. Any ideas ? Quote Link to comment Share on other sites More sharing options...
wkw90 Posted February 7, 2008 Share Posted February 7, 2008 Just stuck a 4.2 V8 in my 90. It will start but only on a key flick. If it goes on to crank it won;t start. So its key flick or nothing So it's like the crank is drawing too much power and stopping something working. Fuel pump seems the same, and I think I get spark on crank.Any ideas ? I had a problem like that on my transit , it turned out to be the crank shaft sensor was loose , and would move as the engine would turn over . Paul Quote Link to comment Share on other sites More sharing options...
tacr2man Posted February 7, 2008 Share Posted February 7, 2008 your missing a live feed that supplies power thru relay to ecu switched by oil pressure ensor IIRC HTSH Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 7, 2008 Share Posted February 7, 2008 I thought it was the white/red from the starter solenoid that supplied power during cranking, certainly tis on Flapper setups, goes through the steering unit on those but probably more direct on a 4.2. It could be firing from the priming pulse if you give it a quick kick but getting no further if it doesn't catch as the ECU is dead whilst cranking. Quote Link to comment Share on other sites More sharing options...
mad_pete Posted July 20, 2008 Author Share Posted July 20, 2008 I think my ECU is dead when cranking, the relays click off as the key moves to crank position and don't re-click when cranking begins. Can I just plumb a live from the starter solenoid ( red brown ? ) to the ignition ECU feed to give it juice while cranking ? Quote Link to comment Share on other sites More sharing options...
Landowner Posted July 20, 2008 Share Posted July 20, 2008 Just stuck a 4.2 V8 in my 90. It will start but only on a key flick. If it goes on to crank it won;t start. So its key flick or nothing So it's like the crank is drawing too much power and stopping something working. Fuel pump seems the same, and I think I get spark on crank.Any ideas ? Could be wires on starter solenoid wrong or wires on key start on wrong terminals. Switching off power to bits and bobs when turned to crank position. just a thought Quote Link to comment Share on other sites More sharing options...
mad_pete Posted July 21, 2008 Author Share Posted July 21, 2008 Could be wires on starter solenoid wrong or wires on key start on wrong terminals. Switching off power to bits and bobs when turned to crank position.just a thought Should everything that is live at ignition be live at ignition + cranking ? Quote Link to comment Share on other sites More sharing options...
iomlt Posted July 21, 2008 Share Posted July 21, 2008 Should everything that is live at ignition be live at ignition + cranking ? I had this EXACT problem, trying to start her and you had to flick the key at the right point just after compression so when flicked the key (let go) it would still turn over half a turn just alow her to fire, it was a pain timing it right! lol My cause of this fault was..... The magnifier that bolts on to the side of the Dizzy. replaced that and BANG fired first time on the key everytime! Love faults like that once fixed there perfect, I also ran a extra negative from one of the small bolts of the magnifier to help as sometimes they get lack of earthing and this can cause the failure. Quote Link to comment Share on other sites More sharing options...
mad_pete Posted July 21, 2008 Author Share Posted July 21, 2008 Well there we have it. The ignition feed to the ECU was plugged into something that was ignition live but not cranking live. I plugged it into something else and rock and roll. Quote Link to comment Share on other sites More sharing options...
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