95 3.2 Sov. Hard to start when hot........ Help!!

[Jim AK]

As above really, fine when cold but hot is a real struggle!!

Read codes, nothing registered. MAF ok, Cam sensor ok, Coolant temp sensor ok so im now sort of stuck.

Anybody got any ideas?

Thanks in advance.

[melhookv12]

Google x300 Rochester valve. Located in front of NSR wheel. Simple to test.
Does it smell rich when it finally starts ?

[jimdollar]

Most likely fault is the crankshaft sensor. Try checking the resistance when it won't start and you might find it's either open circuit or reads in megohms. The funny thing is the car will often keep running when hot but often won't start if you switch off until it cools. The other trick you can try is pouring cold water over the sensor,if it restarts then you know it's the sensor that's faulty.

[Jim AK]

jimdollar said:

Most likely fault is the crankshaft sensor. Try checking the resistance when it won't start and you might find it's either open circuit or reads in megohms. The funny thing is the car will often keep running when hot but often won't start if you switch off until it cools. The other trick you can try is pouring cold water over the sensor,if it restarts then you know it's the sensor that's faulty.

Thanks for the suggestions.

Crank sensor is fine, as are Temp sensor & ECU. There are no codes present.

Going to change plugs & leads, clean throttle body etc & see what that does.

Cant do much with the Rochester valve until we get it running. A google session tells me new ones are like hens teeth but i can possibly clean it with an air line at no more than 3 psi....... We shall see!!

[melhookv12]

See if it holds a vacuum. Basically when knackered they would vent fuel vapours into the engine which flooded it. Maybe remove the pipe to the engine and see if it helps.

[melhookv12]

A faulty cam sensor will cause poor starting but this should be hot and cold and should bring a code.

Check fuel pressure. Leave gauge on and see how quickly it comes back up when ignitions is turned on.

[Jim AK]

Thanks for all the suggestions & sorry for late update.

I've changed plugs & leads, cleaned throttle body & it starts from cold much better.

Smells rich when running & seems to need at least 2 goes to start from hot, I've tried this with & without fuel cap in place & it changes nothing!

[Jim AK]

Finally fixed.

Turns out it was the Cam Sensor after all despite being perfectly lined up!

Got no fault codes up & actually only discovered the issue when I disconnected it & the car still started as bad as when it was connected!

Needless to say, the offending part is no longer available but the Bay of Fleas yielded one for the princely sum of £24.

Car now starts better than it's ever done!