Cabriolet is difficult to start

[JonWood1982]

Hello,

First time poster here (& new to the forum) so if I have done something wrong please tell me not shout and I will sort I have looked through previous posts before typing and couldn't find and answer.

My 1998 Rover Cabriolet 1.6 is giving me issues when I try to start it. Occasionally it will start fine and other times I give up trying. The engine will kick in (from the starter motor) get to about 1k revs and cut out immediately. I can be trying to start it repeatedly and all of a sudden it will take and leave it running, other times I just give up.

Recent jobs completed;
Head gasket (done by a mechanic)
New spark plugs about 1k miles ago
New distributor cap and leads
Coil replaced (by a mechanic)
New starter motor

I am now running out of possible options for what could be causing this and any advice would be appreciated.

Thanks in advance
Jon

[RoverRevival]

Check and clean all your earth cables especially the ones on the slam panel near the battery.

[Kriss707]

Try replacing (if you haven't already) the Rotor Arm as they have a resistor in them & this can fail. I'm assuming it's a K-series from the year.

Mine was missing intermittently for months before going completely.

I keep a new one in the boot now just in case/when it goes again.

[itcaptainslow]

Is there any pattern to when the starting problem occurs? When cold/hot? Some more background info would be helpful in narrowing down the potential causes.

A couple of suggestions in addition to the above-the coolant temperature sensor should be checked for the values it is reporting-you can do this with a multimeter. With the engine cold it should output around 4v, falling to 0.5v with the engine at normal operating temperature (around 90 degrees). If the values being reported are incorrect, the fuelling will be affected.

A cold and hot compression test should be carried out to rule out something like a sticking valve-you’re looking for even compressions (no more than a 10% variance) across all four cylinders to the tune of at least 150psi.

When the starting problem occurs, check for a spark, first of all at one of the HT leads, then if there isn’t one here, check the king lead from the coil. If there is one here, then it’s a distributor/HT lead issue.

It could also be a crankshaft position sensor-the ECU uses the pulse from this to provide the spark.

Hopefully the above gives a few checks you can run!

[JonWood1982]

Thank you all for your comments - given me a busy weekend!

RoverRevival, copper grease purchased & I tried to do this today but was rained off - try again at the weekend (assuming it's dry)...

Kriss707, the rotor arm has been replaced (same time as the leads) but I omitted it from my list in error (as with the coolant temperature sensor). Yes, it is the lovely head gasket K-series engine

Itcaptianslow, there appears to be no logic or pattern (that I have noticed). Slow to start the other day, I stalled it on my return so the engine wasn't cold and it still caused the same issue. The coolant temperature sensor was replaced with the head - mechanic noticed when testing his work (sorry another item I forgot to mention!). Where do I point the multimeter to test this, or is this no longer required as it has been replaced?
I will Google and review the crankshaft sensor (just so I know exactly what I am looking at and what I want to see / not see).

I will update once I have been through this list, hopefully with positive response...

Kind regards
Jon

[itcaptainslow]

On the pins of the sensor itself (where the wiring harness goes onto the back of it) with it still in the housing, engine off.

Has this all come on since the work was done?

[roverman2020]

hi there mine has honda engine and when i go to start a week later once it not been started foe a week battery is flat what can be causeing it please ad sorry to go slight off topic

[JonWood1982]

Have you had the battery checked? (Halfords will test for free, but other places are cheaper). It is possible the battery is no longer able to hold a decent charge.

[JonWood1982]

Itcaptianslow, thanks, I will take a look on Sat/Sun. As for occuring since the H/G - not really, but it has worsened. I assumed the starter motor was causing most of the starting fault.

Had it 18 months and starting was occasionally an issue but infrequently, and always started after a few tries.
H/G done in April/May but it has been frequently an issue only since colder weather has set in, hence leads etc being replaced.