1.9DG struggling to start cold, dies on throttle, no guts.

[ianio]

Hi, 

first post and i have to admit to being beaten. in more ways than one. i recently married into a T25 issue. im for the Aircooled myself. 

The 1.9DG was installed in a kamper that had blown its last engine. its had a full second hand engine and all ancillaries are transferred from the old. 

it wont start without easystart but once its ticked over for 1 in its just about ok on its own. 

---------The Key Issue----------------
touching the throttle causes the revs to fall off a cliff. usually stalling or recovering when throttle is released. its completely gutless and cannot drive along except on full revs which takes time to build up. 

---------history and checks so far------
the carb (pierburg) was fully cleaned and rebuilt using a kit in the change over. apparently by the best in the business. lucky me. and an alt carb was fitted but made no difference to the cold start and die on throttle issues. 

thinking it was a vacuum advance issue i have changed the vac pipes and checked to see the dizzy rotate when i suck hard on the vac advance pipe. brake vacuum feed pipe looks decent. airbox looks decent too. 

any suggestions at all from you lovely peeps. where to continue the investigation next?  
 

[Hinesy]

Assuming the carb and vacuum are all tested as OK as you mention I'd be looking at fuel filter, fuel pipes and fuel pump next.

[AngeloEvs]

I always look at the plugs to see if there is a mixture issue as well as all the other possible culprits. If it always starts with ‘Easy Start’ then my gut instinct is a fuel problem not an ignition one. Was the Auto Choke also checked and serviced? If not is the Auto choke working correctly as it is linked to the throttle assembly on the carb - with a cold start, when the accelerator is pushed down to the floor the first time the choke butterfly should operate.engages. If I have that wrong then someone will correct me but I converted my van to a manual choke and I have to press the accelerator down once so that I can engage the choke so I know it is linked.

Is the van used daily or is it left parked for a few weeks?

[ianio]

Hi. Thanks for responses.

I have checked and there is a healthy squirt of fuel into the carb.

Will check the choke and see if it's holding open when cold.

Any ideals on dying when throttling?

[Stesaw]

Timing ok?

[ianio]

ahh well. timing was the first thing on the to-do list and we ended up guessing by ear. since then i found the details on here and set to 35deg BTDC at around 3k revs when warm. turns out we wernt far wrong in the end. 

however the is no movement from the auto advance like i was expecting. i expected the marked nitch to crank over and then return to 35 degs. but it just moved striaght to 35degs point and stayed there. i suspect a vacuum advance issue on the dizzy maybe? 

but in short the timing is ok as per the instruction on this page, subject to subtlety of auto advance operation. 

[ianio]

Hi all, 

i decided that i dont trust the carb rebuild afterall. that would explain the cold start issues and the die on throttle issues. carb removed for tests.

there are a few threads on the pierburg set up and i skimmed them all. focussed on a couple of relevant factors at least. 

a few noted i would like your opinion on: 

should i be able to suck through the choke pull down diaphragm pipe while it is cold? is it temp dependent. i can easily suck on the pipe. 

should i be able to see daylight through the two fuel jets? currently only see through one when holding it up to the sky. 

how critical is are the various gaskets? the gasket/spacer onto the inlet venturi is new but the inlet casting surface is rough and could be leaking. spraying engine starter on it when running didnt seem to make any difference though. 

i noted there was no inlet fuel filter so suspect something got blocked and also suspect the choke is fubar somehow. 

does all this sound reasonable. barking the wrong tree.?
 

[ianio]

choke pull down replaced from an old carb. 

also found that secondary phase plastic clip had broken. big fight to swap the whole butterfly and axle from the old carb, since the plastic clip is rivetted onto the axle.

now its all build and heading back in the bus tonight.