LLE won't run after ECU swap

[matt&su]

I've a '92 LLE 2.1 SS engine'd multivan, which for a long time has been intermittently overfuelling with no logic or pattern as to when it will run ok & then not. A few different mechanics have tried solving the issue & along the way have changed or tested various things, to no avail. As a last resort i sourced a replacement genuine bosch/vw ecu, which having swapped over has resulted in the engine failing to run at all - will turn over & fire but has no throttle so just dies with a cough & a splutter. What's most concerning is that now even with the original ecu back in, when starting & running to some extent was never an issue, exactly the same thing now happens & engine will not run for more than a few seconds. Things checked &/or replaced to date in search of a solution include fuel tank (was perforated & corroded so initially thought the lumpy running could be down to muck in the fuel system), temp sensor, lambda, fuel injectors, coil, plugs, distributor & earth wiring. Had intended to change the AFM next if the ecu did not solve anything so have been on lookout for a compatible unit, but now the ecu swap has knocked everything out of whack anyway i need to at least get back to where i was!! Any ideas welcome....
thanks. Matt

[silverbullet]

There is something in the back of my mind about bad or broken earths causing Digifant ecu failures (tesults in a board component blowing iirc)
Not an expert, sorry.

[mark]

you need to have bright clean connections on all the plugs and earth connections.......contact cleaner and a tooth brush..........from an earlier thread I recall that a disconnected earth at the ecu will fry it.....off for a look........ have a read of the link. don't spend anymore money until your definite that you have sound wiring and earths right through the engine bay

https://club8090.co.uk/forum/viewtopic.php?f=37&t=142726" onclick="window.open(this.href);return false;

mark

[R0B]

Probably a daft question,but are you using the correct ECU.Autos and manuals are different.

[Highroller]

I see that you have swapped out a lot of things but what about the ignition amplifier?

[matt&su]

Thanks for the comments all.
mark - suspected wiring may be iffy as have occasionally had issues with the interior lights dimming/flickering but mechanic says all wiring is sound & earths ok
rob - defo the correct ecu, same code number as originally fitted
highroller - will mention this when next at the garage

'Tis looking like my 2 weeks camping in cornwall in 3 weeks time might be going to the wall - won't be the same in the back of a seat leon.....!!!

[Aidan]

if the afm is disconnected it will start and not run/respond to throttle and die when you try to drive it