Ok so im having a really hard time pin pointing some very annoying faults with the car:

 

1) At high speed and at high revs there is an electrical fault. For example, as i approach 60mph in 3rd gear the lights go really dim and all the electrics in the car flicker and pretty much cut out. But its only in this gear at this speed. :headvswal

 

2) Power steering cut out yesterday for about a quater of a mile. then has been fine since. :headvswal

 

3) The is a really serious sound noise coming from underneath the car, but it is tempramental. It sounds like a twig stuck in bike spokes, but its loud enough to be heard from several streets away (ive had people tell me theyve heard me coming just from this noise). The frequency of the noise is directly proportional to wheel speed, not engine speed. Its coming from the front of the car, however it changes sides, sometimes it sounds a bit to the right, sometimes to the left. and some days its not there at all. The noise goes away on acceleration. I will try and get a sound recording of it. :headvswal

 

Any ideas? :bow:

 

EDIT: Oh yea its a 91 NA Z32.

the high speed thing sounds like a loose battery connection

check battery connections and all seems fine.

 

2) Power steering fault is now getting more frequent and lasting longer, this is getting quite a dangerous feature and is making the car undriveable.

 

4) Flat-spots in acceleration have started to appear between 1-3k revs in every gear :-S

My first guess would have been loose battery cable as well, have you checked them all not just at the battery?

If the car has been converted to MPH it can sometimes cause loss of steering power, search on here will help with that one.

Flat spots could be any number of things, not sure where I would start.

3 .

i had a similar noise from below the car.

Found it too be a bearing in the prop shaft was failing,

noise changed when i put my foot down and sometimes wasn't there at all.

 

hope this helps

i did a search and i found quite a few people with similar problems, but none of them seem to have got back with a solution lol. Is it just something i have to live with or will replacing the convertor chip fix the problem?

 

I just checked the battery, ill check the alternator etc tonight :-)

 

Yea, bearings in the prop shaft were my first thought with the location and speed of the noise, can these be checked visually or is it worthwhile just replacing them anyway?

 

Wasnt sure if any of these faults were connected, but its not seeming like it.

mine was the needle bearings in the universal joints on the prop shaft

i spotted they had a dry rust type colour residue,

solution i bought a single piece prop shaft from z1 for about 200 quid

 

http://www.z1motorsports.com/index.php?cPath=6_11

check the fluid level in the power steering pot,

 

check the alternater belt, maybe that could casue some issues at high speed