Hot start problem finally fixed
Following a recent body lift chassis restoration there have been a few problems to sort out but the most difficult to trace was a Hot Start issue. Not the usual Hot Start issue where the engine refuses to crank but a failure to fire. The car always started from cold but when warm or up to temperature although it always cranked it refused to fire. The immobiliser was bypassed to no effect. Initial thought was that it could be an ignition problem so I changed the coil and the fault appeared to go but returned after a day or so. Next it refused to start from cold so the ignition amp was changed and as it started OK, thought I had found the fault and marked the old ignition amp faulty only for the fault to return after a few days. The distributor pulse generator did give a small voltage kick when the toothed wheel was moved and the car started from cold but the air gap seemed on the large size so was reset to 0.25mm. Again the fault appeared to be cured only to return a few days later. As there was a good spark on number 2 plug I decided that the ignition was probaby OK and that the problem was probably fuel related.
As the fuel pump and fuel filter were new I could discount both. The fuel pressure was measured at the regulator and was fine, but I did notice a small kink in the main fuel fuel line so replaced it, the fault remained. The return feed was checked and was free through to the tank. Thinking that fuel vaporisation was about the only thing left I looked for a cause but could not find anything. Running both Rover gauge and an Ecumate test did not show any fault codes so I was completely foxed.
After a few days with the car idling I inadvertently touched the small blue rubber two pin plug/socket at the top of the ignition amplifier and the car stalled. Further investigation found that one of the female pins had been pushed back into the housing thus causing a poor contact. The socket was dismantled the contacts cleaned and the pin realigned to its correct position and the car started and restarted. The hot start fault had finally been found after several weeks and many false conclusions. The poor connection must have been heat dependent and changing ignition amps etc. must have aggravated the situation I wonder how many owners have replaced the ignition amps when the rather flimsy plug/socket has been the problem all the time. That was a few weeks ago and after many starts and restarts both hot and cold it has never failed to burst into life so it is finally fixed.
As the fuel pump and fuel filter were new I could discount both. The fuel pressure was measured at the regulator and was fine, but I did notice a small kink in the main fuel fuel line so replaced it, the fault remained. The return feed was checked and was free through to the tank. Thinking that fuel vaporisation was about the only thing left I looked for a cause but could not find anything. Running both Rover gauge and an Ecumate test did not show any fault codes so I was completely foxed.
After a few days with the car idling I inadvertently touched the small blue rubber two pin plug/socket at the top of the ignition amplifier and the car stalled. Further investigation found that one of the female pins had been pushed back into the housing thus causing a poor contact. The socket was dismantled the contacts cleaned and the pin realigned to its correct position and the car started and restarted. The hot start fault had finally been found after several weeks and many false conclusions. The poor connection must have been heat dependent and changing ignition amps etc. must have aggravated the situation I wonder how many owners have replaced the ignition amps when the rather flimsy plug/socket has been the problem all the time. That was a few weeks ago and after many starts and restarts both hot and cold it has never failed to burst into life so it is finally fixed.
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