1.6 Cti Cutting Out Once Nearly Fully Warm

[lagonda 42]

Car has been running fine since engine rebuild but obviously that couldn't continue!

Starts fine from cold & then runs fine, but after about 10 minutes it will start to misfire. If I can't keep the revs up, it will die. It then won't start for 20 minutes or so ... then it will start & run happily.

It literally seems to go onto 3 cylinders, then 2, then none. I think it's ignition related as you can smell petrol when it's spinning over.

Have tried known good tachymetric relay, & that made no difference.

Any ideas!

[boldy205 75]

poss worth checking the ignition amp. By the way, where is the tacho relay? and what does it do?

[lagonda 42]

Hi boldy,

 

Will check out ignition amp.

Tachymetric relay is a large black relay, generally found above driver's right foot. I believe it controls the fuelling & petrol pump via signals from the ignition system. If it fails (mine stopped working because of dry solder joints) the car just won't run, so worth carrying a spare.

[steve@cornwall 100]

Sounds like the dreaded ecu temp. sensor , too much fuel for a hot engine

[DamirGTI 345]

Hello !

 

I've had exactly the same problem as you , and ti was : the ignition amplifier (was overheating once the engine gets up to operating temp. - starts runs idles fine from cold , run around 10min. , and then starts first with a strong misfire and the engine cuts out completely shortly after ... then after 5min. of standing , when the engine cools down a bit , it start again no probs until it warms up and all this story repeats again ...)

 

Anyway in my case the ignition amp. was good but the thermal transfer paste at the back of the amp. was dried out which was causing amplifier overheating ... I've fix that with re-applying the thermal paste ...

 

But it could be the coil also the symptoms of these two are in most cases very similar and both of them usually starts to make problems when the engine gets warm - good running from cold , bad once it gets warm (starts with misfiring , cutting out , working on 3 cylinders etc. ..)

 

Deffo the ignition problem me thinks

 

Damir

[Roman 0]

i agree vith damir.. definitive amplifier or coil

[lagonda 42]

Funnily enough I've just got round to buying some heat sink compound as I knew the original paste was pretty thin, dry & probably not very effective.

Damir ... my symptoms match yours, except that once I've got it re-started, it then runs fine, doesn't repeat the cutting out/misfiring.

Steve .... whereabouts is the ECU temp sender? Can it be tested by disconnecting or shorting out?

Cheers

Laurence

[pug_ham 245 3 Cars]

The ecu temp sender is somewhere around the dizzy area, either in a seoerate CTS housing or the back of the thermostat housing depending on the age of your car. Most will have the seperate CTS housing imo which is underneath the dizzy on the side of the thermostat housing.

 

The CTS can be tested for resistance at different temps, basically cold & hot.

 

The range for a Bosch sensor;

• 0'c = 6k ohms.
  
• 10'c = 3.5k.
  
• 20'c = 2.5k.
  
• 40'c = 1.2k.
  
• 60'c = 600 ohms.
  
• 80'c = 300 ohms.
  
• 100'c = 180 ohms.
  

Graham.

[lagonda 42]

Hi Graham,

Would that be the sender which a blue plug attaches to? This is on a separate water housing beneath the dizzy, with the SAD on a plate beneath that.

 

Laurence

[Roman 0]

bull's eye

[pug_ham 245 3 Cars]

Hi Graham,

Would that be the sender which a blue plug attaches to? This is on a separate water housing beneath the dizzy, with the SAD on a plate beneath that.

 

Laurence

Yes, just like Roman said.

 

Graham.

[lagonda 42]

thanks for that, gives me a few angles to try!

 

Laurence

[lagonda 42]

Finally got to the bottom of this!

It was condensation in the distributor cap!

Dried it out a couple of times and since then (about 3 weeks) problem hasn't recurred. Probably helps that I did a long drive (Somerset & back, 240 miles) then whereas previously had been doing very local trips only.

Has anyone else encountered this ... was thinking drilling a hole in the cap away from the segments might help it ventilate & stay dry.