Club 80-90 Forums

2.1 dg running on gas / carb.

can we swap out the four speed for the five speed box? Is it a complete front to back change, or just the box?

Ta
Emma

Why?
What codes have you got?

Unless the 5 speed has higher ratios then it wont gain you anything..

Early or late 4 speed?

Knew there wouldn't be a quick answer.....

will go find the codes...

then maybe we will have a clearer picture.

thanks Simon

Emma

Em, why you want to swap 4 speed for 5 speed??

I've driven both extensively and I much preferred the 4 speed, more gear changes mean more fuel consumption.... well that's what I found anyway is the 4 speed knackered??

Being in the correct gear more of the time means better fuel consumption, given that you know which is the correct gear. If you mainly do motorway stuff then the highest ratio box regardless of how many gears is probably best. If you mainly do town driving then as many gears as you can get for best economy though your arm may get tired.

Five speed boxes are widely accepted as being the weakest of the three options, autoboxes are "known" as the strongest i.e. least likely to break under normal wear and tear.

Individual experience will vary.

we're not sure.....

we've got 2 2.1 running on gas, both on four speed boxes. But they are chalk and cheese......the camper thinks its schumacer, and John's panel (lighter with recon Elite engine) has a Brian the snail outlook on life.

We have a spare 5 speed just in case it is the gear box that is duff. It could also be the "wrong" box - hence having a look at codes may help.

It could also be the accelerator cable - I don't floor the camper - rarely need anything more than light pressure, and always feel resistance through the pedal. Not so in John's - we drove the same hill at the same time (I was behind him) and although he did it in fourth, he said that there wasn't anything left - I feel that I could have overtaken him as there was some spare in the camper.

Our first port of call will be the cable - but the swap was just in case the gear box is up the creek.

I too drive both - the camper is four speed, my 1.9 velle is 5 speed. I don't mind either.

thanks for your reply - think we have a bit of investigation to do. I am hoping that it is not the engine, although its still in its warrenty - no nasty noises, no oil leaks, pulls well if driven quite hard - just doesn't seem to have the revs......

em
xxx

I've been looking a doing the reverse swap (my current 5-speed is dying) and it appears the consensus is that the early 4-speed needs both the bracket and the linkage changing but the later 4 and 5 are interchangeable (anyone confirm/deny if I still don't understand) - if we get a definitive answer this is one for the Wiki I think. I too need to crawl underneath to see which one I have but with this one the difference between 4th and 5th is not enough to make much difference with the engine conversion I have, 5th definitely needs to be taller. To me your fault sounds more like carb (say second throttle not opening, secondary jet blocked) than gearbox.

Richard

Oh, quick PS - guide to which box has what ratios here:

http://www.partsemporium.co.uk/t25_gearbox_codes.htm

Richard,
thanks for the reply.

Will pass that on to the other half. Must admit, I thought that being on gas meant that the nozzles wouldn't block......

Emma

Em funny you should mention being blocked!!!
reminds me I must put up a new query thread....off to do that now..

hope you get whatever is bugging yours sorted..

Does it allow running on petrol as well as gas? If so you can eliminate most carb/gas system faults by seeing if there is any difference if you change fuels (as you say gas systems are less likely to block but not impossible). It should go a little better on petrol but not much and both your vans should change by the same amount. If there is no difference I would suspect the ignition first. If you have a rev counter (or can fit one temporarily, any electronic one for a 4-cylinder car will do) you can eliminate the gear box by seeing what revs you are doing for a given road speed.

thanks for that....and thinking about it, itslumpy on petrol too...so maybe the nozzles are blocked. Hadn't thought of that....jsut feels liek the idle is too low until its well warmed up.

spose it would feel like that if being starved of fuel...

Thanks for hte advice about reve counter as well.

Emma

Less likely to be the fuel system if it is poor on both - only the throttle is common, the jets and fuel metering are separate between the gas and petrol systems, based on various previous problems I would always suspect the ignition first, if it is not idling too well that could be timing related. Probably one of those 'tune up from scratch and see if it helps' jobs, that always seem to take for ever.

Yeah, I would go over it all and check the timng and ignition components for issues.. could alsoi be the second choke vac unit not pulling down so you dont actually get full throttle... these do fail and the pipes connecting them perish... its round the back of the carb so you dont see it easy...

Folks, thanks for all the answers...

now, the engine in this bus is a 2.1.

It has a 2.1 dizzy on it - but is the dizzy cap and rotor arm /coil etc different? I ask as I have a "known good" set-up on the van next to it, but that is running a 1.9dg.

ta
Emma

could alsoi be the second choke vac unit not pulling down so you dont actually get full throttle... these do fail and the pipes connecting them perish... its round the back of the carb so you dont see it easy...

didn't even know it was there....but I do now....

Emma