Nissan TD27 rpm fluctuating at cruising speed (100km)

[blorigan]

thanks for your info- looked like it was a cooing problem that blow the piston - have replaced the motor,
going well apart from one small problem, now is when cruizing along at 100kms the revs jump up by about 100rpm off and on by its self from around 2300 to 2400 rpm
any ideas?

cheers

[BlakeNZ]

are the revs actually fluctuating, or just the rev counter?

[nakimud]

My rev counter is dodgy like that too, possibly just a faulty connection from the pickup wire on alt?

[sibainmud]

Two problems come to mind. First is fuel supply to injection pump or the fuel return from the pump (too free flowing). Did new engine come with pump or did you swap your old one over?

Cheers

[DEAN40]

All Nissans of that vintage, car or 4x4 are notorious for fluctuating and/or failing RPM counters. However they usually play up randomly and not at a specific speed. Check all connections to the diesel pump and the gearbox. Also check all earth points. If there was defiantly no fault prior, then it will be something related to the install process or the parts supplied. If that is the case, don't wast time on anything other than what has been touched or supplied.

[blorigan]

Two problems come to mind. First is fuel supply to injection pump or the fuel return from the pump (too free flowing). Did new engine come with pump or did you swap your old one over?

Cheers

[blorigan]

Two problems come to mind. First is fuel supply to injection pump or the fuel return from the pump (too free flowing). Did new engine come with pump or did you swap your old one over?

Cheers

thanks- yes it came with a fuel pump which looked to be overhauled or a new one not so long back. Revs are actually fluctuating but only at around teh 100km range- will check all connections

thanks again

[blorigan]

Two problems come to mind. First is fuel supply to injection pump or the fuel return from the pump (too free flowing). Did new engine come with pump or did you swap your old one over?

Cheers

thanks- yes it came with a fuel pump which looked to be overhauled or a new one not so long back. Revs are actually fluctuating but only at around teh 100km range- will check all connections

thanks again

[katipo]

Could it be the torque converter lock up clutch locking and unlocking for some reason. This is only supposed to lock when cruising around 80-100kph

[blorigan]

I checked the inlet/outlet from the pumep etc and all were ok, have since moved the electrical control sensor located on top of the fuel pump anti-clock wise by about 3mm and that has corrected the issue.

thanks