Throttle flat spot has got worse! UPDATE

[CovKid]

You can mark dizzy bracket and dizzy for correct positioning with a punch or sharp screwdriver.

[grahamp]

Hi All

These symptoms sound remarkably like those I am experiencing! Just completed a 160 mile trip to the Cotswolds. On the way up my 1990 T25 (<48,000 miles) went faultlessly, despite being stop go on the M25 for 2 hours! The return 7 days later was a different kettle of fish!!! Started fine, blipped the throttle off load - fine. Engaged gear, raised revs, released clutch, lurched forward and stalled. Only way to get her moving was to really increase the revs, slip/dip the clutch and hope. Once moving it was not too bad albeit slow to pick up from low throttle positions. Noticeable at 60 mph in top but ran at up to 75mph with no problem!
I have had this problem on and off for a couple of years (annual miles only <2000!) but it usually clears itself after a few miles. New fuel filter is the only thing tried so far.
Any suggestions gratefully received!

[kevtherev]

make sure you vacuum advance is working.

[CovKid]

was mentioned earlier Kev

[LSW41N]

This thread describes is what is happening to my van. Had a look in the engine bay and I've seen a couple of 'wet' patches (see pictures). Does this indicate any other probs? ..... or confirm the diagnosis?

[grahamp]

Hi All
Further to my post of May 2015. Checked vacuum advance/retard and bob weights, fuel filter etc - all OK. Did one short run to confirm problem before taking her to a T25 expert. Was virtually undriveable!! In desperation removed air cleaner, saw 4 jets looking at me. Poked each with a bit of wire - replaced air cleaner and set off for the expert. Ran like a train. Worked for me - worth a try!!!

Now having having laid her up since October, charged the battery, started straight away - but now have what I assume to be a noisy hydraulic tappit.!! Is it harmful to drive her in the hope that it repairs itself.

[mark]

drive it like you stole it for 20 mins and the engine fairies will make it better.......and change the oil and filter

mark

Hi All
Further to my post of May 2015. Checked vacuum advance/retard and bob weights, fuel filter etc - all OK. Did one short run to confirm problem before taking her to a T25 expert. Was virtually undriveable!! In desperation removed air cleaner, saw 4 jets looking at me. Poked each with a bit of wire - replaced air cleaner and set off for the expert. Ran like a train. Worked for me - worth a try!!!

Now having having laid her up since October, charged the battery, started straight away - but now have what I assume to be a noisy hydraulic tappit.!! Is it harmful to drive her in the hope that it repairs itself.

[kevtherev]

but now have what I assume to be a noisy hydraulic tappit.!! Is it harmful to drive her in the hope that it repairs itself.

drive it for 20 mins rev it and don't hang back.
It should quiet down
as Mark suggests.

oil change every 3000 miles or 6 months, is a must.

[grahamp]

Thanks Guys

Will drive it hard and hope. It appears that I cannot do any harm.
Serviced with oil and filter changed every year, annual mileage <1500! Now 46800!

[kevtherev]

Well, it's every 6 months for oil, filter yearly.
Especially for engines not driven very often.
The oil contains more acids than regularly used engines.


oil's cheap compared to engines.

[grahamp]

I have always been careful to have the oil changed regularly. I only use her May to Oct wrapping her up for the winter. I was not aware of your advice re 6 month changes - all the more important for low use vans.
Cheers

[kevtherev]

Your welcome.
That's why we're here.
As I use mine all year I use 20w/50 in the summer, and 15/w 40 in the winter.
I hope you have a trouble free season.

[SamsBus2012]

Morning all. After changing the vac unit, which cured the problems noted in my original post with dramatic results, the van recently started to develop similar symptons again but only under load and / or at speed. After a few curses of frustration I checked the usual suspects and traced the issue to the small section of vac pipe connecting the front of carb (next to the dizzy vac pipe connection) to the air box. Quick change and problem solved. I seem to recall a post where this connection had been blanked off. So question is, if this connection is blanked off, do you need to do anything to the flaps in the air intake which connect to this pipe?

[ajsimmo]

No.

[SamsBus2012]

Ta