Advice on rough(ish) running

Hi - wandering if anyone has any advice on this.

The other night drove the car and though it started OK first time it ran rough for a first 15mins and in the end stalled. I managed to get it home, but had to keep revs >1500 when stationary.

Yesterday I did some checks.

1. The AAV seems to be working. When I squeeze the pipe when cold the revs DROP. When I squeeze the pipe when hot the revs stay the same.  I adjusted the idle speed to a little higher at full temp to 1100 - to get through MOT 3 weeks ago, they had adjusted that lower.

2. The fuse box looks OK - no water so I think the fuel relay is fine.

3. Given that that the car revs at all temp to 6,000 rpm and drives fine in all gears I think it fair to say the pump is OK.

4. When the car is cold, car starts on the button.

5. When hot the car starts on the button.

So, I took it out this afternoon - not particualrly cold and it's dry (for a change).

– Started OK, on the button
– Initial idle is 1050ish

5 mins later
– 950 rm
– water temp about 0.25 along gauge
– oil temp is —
– engine feels a little lumpy though nowhere near as bad as other day

3 mins later
– 1000 rpm
– water temp midway along gauge
– running little smoother
– oil temp —

10 mins later
– 1050 rpm
– water temp normal
– oil temp = 63
– little more lumpy - after pressing throttle from idle intial roughness then OK

10 mins later
– 1100 rmp
– oil temp = 90
– very smooth - no roughness at idle or through rev range - instant throttle response

Conclusion?

Could it be the Warm Up Regulator?

I'm loathe to take to garage as they will start to replace parts. The pump and accumulator are reasonably new (last 20,000) and it has had new fuel distributor and injectors about 30,000 miles ago. WUR is original though.

Any advice? Does the OHM check on WUR really prove anything?

Thanks

Could it be the Warm Up Regulator?

Replace it or try cleaning the little filter first with a cotton bud , they can be blocked . Located under the pipes .

Took it to the garage - they "tuned" it and gave it back - drove it this morning (not that cold) and same problem. Runs rough for the first 15-20 mins and then once hot goes OK. The idle when hot is fine - so I think the AAV is OK - I did the "squeeze" test and seems fine.

I'm going to check the WUR this PM and see how we go!

Lean it out a little bit.

Checked WUR - voltage is OK and Ohms 22.3 - so OK (though no "guarantee" that all good). The garage has agreed to take back and resolve - paul c will pass on comment -thanks -

it's close - just not there yet!

Right guys I have put a "new" WUR an still have an issue.

1. Car starts - not quite on the button as before problem but it does start.
2. Seems to idle too low given it is very cold (car been outside for 24hr).
3. I drove the car for say 15mins and though the car did not stall when you pull up at the lights the revs drop very low nearly stalling.
4. The car drives through the gears but when pushed hard it stutters and feels being held back.
5. Does not idle smoothly, hunts for idle  
6. If I switch off after warmed up and say leave for 15min, it struggles to start and back fires a little.

Any ideas given the symptoms. Car is an '83 1800 GTI. In the last 5 years car has had;

New injectors
New fuel pump
New accumulator
New fuel lines
New injectors
New fuel distributor
New fuel pump relay

…I think it's fuel related, but I guess it could be part of ignition circuit?

Any help appreciated

Cheers

lean it out a bit