Ok... Ive posted once or twice about this problem but had no come back so I will try to explain it in a bit more detail! When I first fire up my 91 uk tt and drive off while cold the gears go 1-2 maybe to 3rd sometimes? and not 4th but when shes hot I have to boot it hard before it will kick into 4th then it works fine driving normal but when I boot it through the gears it goes 1-2 as normal then its goes 2-4 soon as it hits 4th it kicks back into 3rd strait away then winds up through 3rd then into 4th and will do this all day long this has been going on for nearly a year. I cant get the diagnostic test to work so have no idea of fault codes??? I have done a oil chance a couple weeks ago which looked like this,

oil was brown in colour maybe not changed for a few years??? but no obvious signs of disintegration, spotless infact! which was nice to see!

Colour of oil pic,

 

Does the box have a separate ECU? which could be screwed??

If anyone can help with this that would be great? Cheers...

sent him an email and my log in, he should respond soon....

Excellent mate cheers! :bow:

This is an email from my brother, hope its helpful:

 

How many miles has the car done ?

Motorway miles or short trips ?

Brown oil is old - oxidisation, oil changes can cause malfunctions by stirring up settled contamination.

Box is electronic control ( e c u ) through solenoids ( switches ).

You say "been going on for about a year" so no mechanical or friction related problem.

The box is being "told" to change that way, which is a control fault, ecu or solenoids or valve body etc.

Give a mate YOUR ecu FIRST to try on his car, then his ecu on yours if he has no problems

This is an email from my brother, hope its helpful:

 

How many miles has the car done ?

Motorway miles or short trips ?

Brown oil is old - oxidisation, oil changes can cause malfunctions by stirring up settled contamination.

Box is electronic control ( e c u ) through solenoids ( switches ).

You say "been going on for about a year" so no mechanical or friction related problem.

The box is being "told" to change that way, which is a control fault, ecu or solenoids or valve body etc.

Give a mate YOUR ecu FIRST to try on his car, then his ecu on yours if he has no problems

I have to say mate that your brother is totally right! got a used ECU from paul at SWZ for a price of £20! stuck that in and she works perfect!! chuffed to bits now :hyper: been waiting a long time for this! but there is one thing id like to ask and that is whats that orange light about on the dash next to O/D light??? comes on when I boot it but not all the time I think? but doesent flash goes out when I take my foot off is it just a boost light?? but anyway mate have a :duffer: on me!!!

I have to say mate that your brother is totally right! got a used ECU from paul at SWZ for a price of £20! stuck that in and she works perfect!! chuffed to bits now :hyper: been waiting a long time for this! but there is one thing id like to ask and that is whats that orange light about on the dash next to O/D light??? comes on when I boot it but not all the time I think? but doesent flash goes out when I take my foot off is it just a boost light?? but anyway mate have a :duffer: on me!!!

sounds like the "power" light mate,comes on when you floor it on s1 only,s2,s dont come on when booted hth ;)

sounds like the "power" light mate,comes on when you floor it on s1 only,s2,s dont come on when booted hth ;)

Oh right cool!! as long as its nothing wrong with box!! cheers mate!!

http://www.300zx.org.uk/gear_ratios.htm

 

Gearing is about 28mph per thousand on a TT auto. (25.7mph/1000rpm manual) so 2857rpm @ 80mh and lock up to be pedantic! My 2600ish was prolly down to speedo error and the true speed was more like 76mph

 

25.2 per thousand apparently for a NA!

 

As far as I know you cannot hold lock up. Only the box ecu can decide when it locks up and the conditions are explained in the auto transmission manual. Basically light throttle and high speeds.

 

Power mode usually just keeps it from going into OD.