V8 starting problem when hot

[ESPREE 2]

Just an update... Fuel pressure is ok at all times, plugs are fine, but there is NO spark when the problem is occurring (engine hot). So definitely electrical. Will go for a new crank sensor (and maybe get a cam sensor just in case). Will post back with the results.

[Günter 27 1 Vehicles]

Kent, what type of cam do you have --the one with the 'cam angle braket' srewd onto the camshaft, or as integral part ?? ..this would be interesting, to find a clue on what is going on with possible miscalculations by the ECM

[ESPREE 2]

Hi Gunter,

I am not sure what kind of cam sensor the original was, but the new one (ordered from JAE) lists as a "Sensor, Cam angle" part # E-6010-918. Pricey at about $300, but worth it I suppose. The Crank Sensor was listed as a "Speed Sensor, Inductive" at about $46 and part #: E-6080-918.

I heard back that the mechanic DID indeed resolve the problem. YAY! He replaced both sensors (crank and cam), and also added another ground wire from the battery to the ECU.

I will try to get some clarification on which fix actually resolved the problem.

[Günter 27 1 Vehicles]

it's not the sensor what I mean, it is the type of camshaft-end. There is a note in the workshopbook that on some engines a camshaft with seperate 'bracket' was used, this acts as signal reference for the 'cam sensor' .. and as such, if not fitted into the exact position relative to the camshaft would give irritations on the startup. So even if you'rs is an '99year-production car ..was there ever a replacement camshaft, maybe sourced from an other 918 engine, fitted to it ?

[ESPREE 2]

As far as I know it has the original camshafts. Wouldnt a misaligned bracket cause running problems and issues on cold start too?

At this point it would seem to be the electronics in the sensor not working properly when hot (like many electronics that tend to fail initially when temperatures are high). Then when it cools back down it functions properly again.

But I'll try to get some more details from the mechanic on everything.

[Günter 27 1 Vehicles]

Kent ..that's right, from this point of view ..so if it is only under 'hot' conditions the misplaced bracket does not sound like a logical clue. And from period of production your car should be fitted with the 'integral' type of cam-shaft ..as far as I can remind from last time I've read the books. (my '98 type engine does have the integral version too..)

-the heat is transfered from RH exhaust pipe upwarts ..so the cam-sensor in the RH head is in this area, but even with this I would not like to pay 300bucks for it -have you looked for some more common 'reference parts' ??? Was the sensor wiring checket first, and the system verfied with a sensor from an other car ?

[ESPREE 2]

Problem fixed! I drove it today and no problem restarting when hot or cold. The only thing is I still don't know exactly which of the three changes actually fixed it. He pretty much did all three at once (crank sensor, cam sensor, and added ground to block).

He said that as soon as he added the additional ground wire ( from the side post of my Optima battery to the block), the voltage on the battery went up a bit.

So I'm sorry I can't be more specific for anyone else having this issue, but at least it is solvable and it's one of these 3 things. Since the problem popped up as soon as the rebuild was done, maybe the ground wire is the easiest place to start.

[larryk 0 1 Vehicles]

For reference Lotus Garage sells 918 cam sensor for $138. US

[ESPREE 2]

Hi Larry,

Good to know. Are they in the US? Do they have a website or contact number?

Thanks,

[Günter 27 1 Vehicles]

it is this -known (for its usefull shematics..) page, I guess

http://lotusgarage.com/