Juddering...An Interesting Tale

[rmagictastic]

mornin, and here is my story..........

Got the car back with a new engine, all was good boosting and driving great... after about 70 miles when under load the car started juddering and sounded like it was backfiring, the general feel of the car was sluggish and not as pokey as it was before, also idle was a little rough.. Oh No i thought.

so i checked the plugs and found one was black as if it was really rich. changed the plugs...NO change.

 so i started looking at the ignition as i thought i must be getting a weak spark or dodgy contact.

i took the ingnition loom out and made sure that all of the wiring and connections were good, re-tried...No change

i inspected the HT Leads (Magnecor) and ensured that they had clean contacts, tried again... no change

I then thought i would try the bonding and earthing route before i swapped out the coils.

so i disconnected the battery and cleaned the terminals, put a few additional bonding staps around the bay.. tried again  No joy

Got home on the off chance thought i would have a look around the ECU area.........i found that the 2 small earthing/screen cables had broken out of thier ring connector which is held on by a small bolt below the ECU, so i stripped it put a new ring on it tried it and HEY Presto...  all back to normal.

All i can think of is that without the cables connected the signals to the ECU were getting a bit mixed up and therefore the ECU was doing funny things.

Anyhow this has shown...... BE METHODICAL AND THOU SHALT FIND THE ANSWER.

(sorry for the long thread but i think it was a good experience to share)

cheers

Rmaj

[nikp]

Thats a good post - could well prove useful to many people on here!

Well done on the fault finding too - bet you feel quite pleased with yourself.

Have a  :guinness on me!  :mmmm

[rmagictastic]

quite pleased. hehe

rmaj

[royal]

Worthwhile post there mate, glad you find the problem. Amazing how it can be the unexpected. Dave

[Jonathan_F]

Good post. Highlights the earthing problem well.

I\'ll be checking mine tonight. Thankyou.

[Grizzly]

Good spot mate...... Thats one of those faults that have you scraching your head for weeks.

[gsb876]

Well spotted, as they say if at first you dont succeed ......................