Misfiring/cutting out 1989 1.6 CTi

[lagonda 41]

Well, just for a change, no change, still playing up. Even worse, my 1939 Lagonda's engine is out for rebuild (perhaps I shouldn't have used it as my daily driver, but it was more reliable than the CTi), so I have no choice but to drive the CTi.

 

I've recently spotted that "cutting out " is often actually a return to idle speed. Does that help narrow down where the problem might lie? Revving the bollocks out of it seems to help, but I'm too old to be taken for a boy racer by other drivers!

Edited August 22, 2021 by lagonda

[Tom Fenton 1,524]

It’s a setup issue I’d suggest. The idle when warm is a combination of the airflow passing the near closed throttle disc and the airflow via the bypass drilling. When you snap the throttle shut the air velocity stops suddenly and the engine dies before the bypass drilling can supply enough for it to idle. Solution is open up the throttle stop a touch and then wind in the bypass to put the idle speed back where it wants to be. Then reset the switch position. All well and good in theory but the challenge usually is the throttle stop screw hasn’t been moved ever and it’s seized solid in the throttle body housing. Good luck.

[lagonda 41]

Hi Tom,

 I found the bypass screw was screwed right in, so undid it a little. That's put the idle speed up a little, good, but I don't think it's related to my issue. It can be motoring along quite happily, but cut out when I go over a speed bump, or even an uneven piece of road. It particularly doen't like left hand bends (so great fun, not, going round French roundabouts). It's also recently taken to s*dding about going uphill. Nightmare if stuck in traffic as underbonnet temperature increases. If I turn off then, it can be a right b*gger to restart. If stuck at lights, it will eventually restart just as the lights go back to red. For these reasons, I suspect it's a poor electrical contact. I've swapped the distributor signal lead, and the ignition module; no difference.

Laurence

[lagonda 41]

Still no joy, I've tried wiggling any wiring that looks like it might move under centrifugal force, but no cutting out induced. Wondering now if it could be a perished/damaged hose on the inlet side of things?

[PhilNW 40]

Try the connector to the AFM, gave me all sorts of problems with intermittent running.

 

Try disconnecting as well and seeing if the thing runs

 

Could be the fuel pump connector and/or lack of pressure

Edited August 27, 2021 by PhilNW

[camgti 56]

Check your fuel pressure reg if possible. 
 

Also check the connection with the ignition relay. 

[Richard309Sri XU5JA 205GTi 7]

plus any inlet manifold vacuum leaks - ? 

 

[lagonda 41]

Many thanks for all replies. Manipulating the AFM connector and cable made no difference ... puliing the connector, the engine stalled ... surely it should stall? Tachymetric relay is fine, plus it's cable/connections. There is another cable running from the ignition switch, larger gauge individual wires than most of the crap cabling on the car. This runs to a white/transparent plug and socket. Wobbling that with the engine running caused the engine to cut out momnentarily. Could this be it?! I've closed up the female Lucar type connectors, and a 15 mile drive yesterday was trouble free. No heavy traffic, but it was a very hot day, which is usually a guarantee for jerky jerky driving. Fingers crossed!

Not all joy ... clutch slipped when I overtook another car. Grrr. Present clutch has done some 150,000 miles, how long should I expect one to last? Adjusted it a year ago so I suspect more adjustment might not be the answer ...

Laurence

[DamirGTI 323]

1 hour ago, lagonda said:

This runs to a white/transparent plug and socket. Wobbling that with the engine running caused the engine to cut out momnentarily. Could this be it?!

 

Yellow 3pin male and black female plug ? if so , that's the main signal cable for the ignition/fueling .

 

If it's square single or 2pin white plug that'll be coil power supply .

 

Take a pic of that cable/wiring .

 

D

[lagonda 41]

Hi Damir,

  Since that, went for a 50 mile drive on a very hot day, 37 degrees C. That would pretty well guarantee cutting out/stalling, but all went pretty well. Not 100%, did verge on stalling at one point, but normally with that heat it would be a right pig. Perhaps I'm on the right track.

 

 Here is a photo of the cabling in that area. Tachymetric relay dangling to the left; that isn't a connector on its cable, just a paper label. The clear/white plug and socket I'm referring to is just above that. As you can see, it's the wiring from the ignition lock switch. There are 4 wires going in. The car is a late 1989 CTi, with a normal ignition coil behind the battery, not the weird type bolted to the inlet manifold.

 

Hope this helps!

 

Laurence