Disco 1 95 v8- surging\pulsing at 3k rpm

[auscoz91]

Hi guys i have a 1995 disco 1 v8 with 19xxxxkms auto
when sitting on 70-110(generaly 20% at -60kms 80% 60+kms) at roughly 2k-3k pm i get surges and if i dont give it some boot it will constantly surge (kind of like a rookie manual driver lol-bunnyhop) even giving it some boot it will still surge but will just give me a second of relax haha.

A few things ive noticed is that this has progressed over a year and gotten alot worse in the last month or so, i have used premium\boosters etc replaced fuel filters cleaned stepper motors and put some carby clean through it, im now looking towards it either being the maf\tps\oxygen sensor as some others have had this same problem and these have been the fix. now before i go out and buy a new tps wich ive just been quoted 330$ for :| for a tiny lil gizmo, i would like to know is there a way to test these with a metre?

Also not sure if related but i have high pressure at the fuel cap and sometimes it makes a whine when the cars off, i have also seen that the valve could be blocked could this be related?

[98discovery]

Check your timing I advanced mine from 9 deg to 12 deg and a similar surging, though not as dramatic disappeared.

[bee utey]

Try disconnecting your vacuum advance. If this helps then your dissy pickup locating ring may be worn, allowing the timing to go out of range when under vacuum from part throttle. You can tell if this is happening by looking at the tip of your rotor button. If it's all burnt at one corner only then you can imagine it moving away from the cap contact under vacuum. A wider rotor button can help, I sometimes use a Bosch GB864 off a Falcon XF. Seems to work well.

[auscoz91]

Try disconnecting your vacuum advance. If this helps then your dissy pickup locating ring may be worn, allowing the timing to go out of range when under vacuum from part throttle. You can tell if this is happening by looking at the tip of your rotor button. If it's all burnt at one corner only then you can imagine it moving away from the cap contact under vacuum. A wider rotor button can help, I sometimes use a Bosch GB864 off a Falcon XF. Seems to work well.


hey mate do you mean the little tip that hits the contacts on the dizzy like the bit that spins lol it was burnt on one edge ive gave it a clean up so if thats the case i could need a new dizzy button?

[ozscott]

Thry have week ignition made worse by subtle shaft play at high klms. You can the replace the hei module, the pick up coil, the button and cap etc like I did on my 95 d1 v8 with incremental improvement but ongoing problems or get it sorted once and for all and never have another problem - Scorcher Ignitions dizzy homologation of Australian Bosch Ford and Holden Dizzy and module and coil to suit...awesome strong idle, with no rolling, much better power and slight improvement in economy. If you ever need a cap or button get it anywhere cheaply. ..I have never needed to replace my cap or button. ..unlike rover holden didnt build them as an item to be replaced every service or so.

Cheers