S1 engine cutting out

[NZDave]

My S1 engine (2.8 with Bosch K Jetronic injection) cuts out when dropping back to idle. If restarted at idle it is quite happy to sit there idling. Anyone got any suggestions?
Dave

[Barry S1]

Check all the hoses if you have a small
hole it will cause lots of problems.

[phillpot]

NZDave said:

Anyone got any suggestions?

get a 2.9



As Barry suggested, check for air leaks, don't know what its proper name is but isn't this big rubbery thing prone to perishing/splitting with age..........








There's a fair bit been written over the years about "issues" with the 2.8 engine, have you had a good rummage through old posts?

I find Google search works better than the actual forum search facility, good luck!

[greyhulk]

Fear not, for I have been through this most annoying issue myself! Drove me mad! The car would cut out as slowing down for traffic lights, traffic etc (but mine wouldn't start right back up for a good 5minutes or so.)

As the guys said check your hoses, vacuum hose from servo to plenum etc.
Now my 'culprit' was a split in the airflow meter cap (black rubber cap thingy), plus the plate had dropped inside the air flow meter, mixture way out so was generally in a bad way.

Check 'Tickover' or Scrapyard's for Capri air flow meter cap (if it is that)

Edited by greyhulk on Tuesday 14th June 08:19

[Kitchski]

If there aren't leaks, it's possible the air bypass screw just needs adjusting.

[Le TVR]

Kitchski said:

If there aren't leaks, it's possible the air bypass screw just needs adjusting.

Probably this

What is the idle speed?
My 2,8 will happily idle down to under 500 RPM but then everytime I rev it and let it drop back to idle it stalls, bringing the idle up to at least 700 RPM and everything is fine again.

[NZDave]

I have had a good look for leaks but may have missed something so I will have another good look tomorrow. Hopefully if there is a leak it is something I can find easily as 2.8 injected Fords were very rare in New Zealand and parts could be hard to find. The idle speed is about 800rpm and I have had a fiddle with the adjustment screw so I don't think it is idle speed.
Dave

[greymrj]

Hi Dave, a bit difficult to help as there are so many possibilities but I would agree to check for air leaks first. It could be quite small and difficult to find. Try a trick: get a length of hose, 1/2" bore would be convenient. Put some cotton wool in one ear and put the hose to the other, move the hose around all the air and vacuum hoses, including those on the alternator side of the plenum, listen for any slight hiss. Listen round the back of the air filter box, under the air valve cover etc etc. Rev the engine a little and try again. Drop the revs suddenly and listen again. It MUST be absolutely airtight on the 2.8 especially. (On the 2.9 the electronics will compensate to a degree, it wont on a 2.8!)
DONT play with anything else until you are absolutely sure it is airtight or you will just add problems to find!
It can be done in other ways but this is cheap, cheerful and works!

When you are SURE (absolutely sure!!) it is 100% airtight then just check the throttle operation especially on the top of the throttle body. It isnt linear and can stick and release, make sure it is clean, there are no worn bits, and lightly lubricated (WD40?)

Then come back to us!!

Good luck

[GreenV8S]

I've never tried listening for air leaks with a hose but I imagine there's quite a trick to it in a noisy engine bay. An alternative approach is to spray WD40, a cold start spray or similar around the area you want to check, while the engine is idling. If the revs pick up you know that the spray is being drawn in.

[NZDave]

Couldn't find any obvious leaks but while looking at the motor while it was warming up decided to check the bolts holding plenum chamber to the inlet manifold. They were all much loosed than I expected. I had a change in idle speed when I did this so suspect there may have been a leak underneath. I went for a couple of short runs, adjusting the idle speed in between and it seemed the problem has gone. However they were very short runs as it is cold today (8C) with showers and a strong cold wind. Not TVR weather at all. I will only find out if it fixed once I go for a longer run and that will have to wait for a warmer and drier day.
Dave

[Le TVR]

Checking that the inlet plenum bolts are tight is part of the routine maintenance for these engines, can't remember the interval though.

[GreenV8S]

Careful not to overdo it - they only need around 15-20 lb ft and it would be easy to strip the threads. A smear of hylomar can help the plenum cover seal without a big clamping force.