None starter...but all electrics and obvs bits checked
None starter...but all electrics and obvs bits checked
Author
Discussion

TVR_Craigy

Original Poster:

1 posts

71 months

Thursday 13th February 2020
quotequote all
So I am relatively new to PH for advice....but I have a 97 4.0 Chimp...which is very original....but just wont start. Its been as good as gold for 3 years (since I bought it)...but the start cycle (i.e. crank to firing and running) has got slowly longer, to the point it just wont start. I have fuel...and I have a spark in the plugs (as verified by a mechanic). Its been suggested that the cam shaft could be worn out....and this could be the cause....any thoughts? I have checked cylinder pressure and all are about 150 (not sure if thats good or bad...but it is a few years old!)...so wasnt initialy too convinced on the cam shaft being at fault...but the issue only seems to have started after a major service where a new oil was put in the engine....could this have exposed a warn cam and therefore resulted in insufficient valve operation? I would appreciate any thoughts as this has been a frustrating winters tinkering with no progress !!

Steve_D

13,801 posts

279 months

Thursday 13th February 2020
quotequote all
It will not be the cam. With 8 cylinders not all the lobes on a cam will wear out at the same time so it will start but just not run as well as it mite.
I have seen cars with several lobes almost non existent and the engine still runs as smooth as silk.
An oil change or the use of a different oil brand/grade will also not cause a non start.

If, as you say, you have a spark then you need to be looking for fuelling or air intake issues.

May be worth getting rovergauge and looking to see if the ECU is getting the right signals.

Steve

blitzracing

6,417 posts

241 months

Friday 14th February 2020
quotequote all
You could try a good dose of easy start to see if it will fire. You just need to get it in the plenum by either removing blanking plugs, or take the pipe off that feeds the AFM. Its not unheard of that the engine floods and wont start, so removing all the plugs and letting them dry completely for a few hours may be worth a punt. Also worth checking your ignition timing as certainly on the pre serps the oil pump drives the distributor (I dont know if this is the same on the serp engine) and if it all gets out of mesh, the rotor arm wont point at the correct cylinder at firing and it will never go. Check the rotor arm is pointing at number one plug lead when number one cylinder is on compression near top dead center.

Mutley00

295 posts

144 months

Friday 14th February 2020
quotequote all
A long shot I know, but l look for the simplest things first - were the plugs changed and were the correct ones put in with the correct gaps? Ignore this suggestion if the service was done by a reputable TVR specialist!

Good luck

Barreti

6,687 posts

258 months

Friday 14th February 2020
quotequote all
Have you checked the basic ignition bits that wear out - like your distributor cap and rotor arm. HT leads, coil & ignition amp are all potential suspects too. Individual HT leads would likely lead to poor running rather than not running but the king lead from the coil to the cap could be a strong suspect.
The other way of fault finding something like this is to swap bits from a known good car.

Penelope Stopit

11,209 posts

130 months

Friday 14th February 2020
quotequote all
Got spark

Got fuel

Got good timing???

Wonder if the bob-weights have stuck in advanced position

or

As mentioned above, distributor drive problem