V8 hot start problem - the definitive thread

[swindon_alan 1,648 1 Vehicles]

Hmmmm. I'm going to get the OBD reader out over the weekend and find out what voltage the ECM is seeing when the engine is cold/hot and with ignition on/cranking. It doesn't do the Lotus built in Low Voltage Headlight Spasm (tm) signal for any of those conditions but it will be interesting I think.

[deloreanmike 0]

The primary injectors leaking down is a very common problem on the V8s. I just fixed this issue on a local V8 this past week. New primaries, no more hot start issues.

[Vanya 530]

Any news on this? My V8 seems to have this issue too, I shall try adding an extra earth between the block and battery and see if it makes a difference!

[swindon_alan 1,648 1 Vehicles]

Hello Vanya. My jump lead between the battery and the block continues to temporarily fix the problem. I have had a few instances where it has come back and you can tell it is the same thing by the failure to start pattern. Remaking the crocodile clip connection (it is on one of the oil unions) immediately sorts it out again. I must get round to replacing those earth leads, thanks for the reminder

[swindon_alan 1,648 1 Vehicles]

*** Update ***

Something my MoT man suggested months ago when I was telling him about this problem. He said not to bother with the earths but to look more at the battery terminals. Do not use the gay screw type (in fact mine were not very tight anyway) but manly bolt down clamp ones to give a decent connection. I bought myself some proper expensive gold plated - yes really - jobbies a couple of months ago but have only just got round to putting them on. I will leave the jump lead earth off and post how it goes.

[HowardRoark 30 1 Vehicles]

Thank you Alan.  I'm interested to see how it goes.   Is that a specific part with a part number, or just a universal terminal?

cheers!

 

[swindon_alan 1,648 1 Vehicles]

Hello Matt. No they were just off the shelf terminals, in my case:

http://www.ebay.co.uk/itm/272165747264

Not that they have to be gold plated either but it occurred to me that then they would never corrode, you don't need to grease them up with petroleum jelly etc.

[HowardRoark 30 1 Vehicles]

On 1/4/2017 at 03:52, swindon_alan said:

Hello Matt. No they were just off the shelf terminals, in my case:

http://www.ebay.co.uk/itm/272165747264

Not that they have to be gold plated either but it occurred to me that then they would never corrode, you don't need to grease them up with petroleum jelly etc.

I got my gold terminals today!  Thank you Alan.  

[swindon_alan 1,648 1 Vehicles]

Woo! It looks as though the gold plated/proper screw down battery terminals have done the trick! I had a good long run in the beautiful sunshine today back from Reading (stayed over after Henley last night), got it nice and hot with the right foot pedal, stopped several times and it started again immediately.

Fingers crossed that is it. Phew, after all that.

I would recommend getting some anyway as they do look rather cool

[swindon_alan 1,648 1 Vehicles]

Updated fix list:

1. Earth jump lead (easy fix)
2. Replace battery terminals with good clamping (optionally gold plated) types
3. Renew engine earth braids
4. Charcoal canister - all US + ROW '01 on -  if you can vent the fuel filler cap(s) and get the engine to start, then it is excess fuel vapor being purged into the manifold via the charcoal canister (easy to diagnose)
5. Camshaft sensor (not cheap but easy to do)
6. Crankshaft sensor (cheap but more difficult to get to)
7. Secondary fuel injectors - the o-rings on the secondary injectors are known to leak into the manifold, since they are galley fed injectors rather than the normal rail fed.  This often happens immediately after someone has disassembled the manifold and re-assembled it, since the o-rings get smashed or cut (cheap but some work)
8. Secondary fuel injectors failed and leaking (2 x $50-ish and some work)
9. Primary fuel injectors leaking down (more expensive)

[HowardRoark 30 1 Vehicles]

Hi Alan, 

Gold terminals installed, and car starts right up when warm!   Seems to have solved an issue.  I will keep an eye on it and update. 

Cheers

[HowardRoark 30 1 Vehicles]

Gold terminals are working well!  

[kostas86 10]

Very good to know that many have seen resolution with these gold terminals. I might swap mine out just because.

[ESPREE 2]

I was one of the OPs with the fixes for the hot-start, but since my mechanic did 3 things at once it was tough to tell what fixed it.  Glad you folks have continued the research and found that the electrical connection is the place to start!  That's by far the easiest/simplest solution. 

[MD355 11]

Hi to all !!

I recently changed head gaskets on my V8 (used OEM to be safe) and also replaced water pump, thermostat, Idle Control Valve, Oxygen Sensors, Spark Plug Cables, and all gaskets relevant to intake...

My car starts easily when cold... but will hesitate (crank but not start) when warm...

I am thinking it has to do maybe with corrosion around the battery terminals...

It is the easiest thing to change...

IF that doesn't work, what do you think i should do next? 

MAP sensor, fuel injectors, secondary fuel injectors, etc ???

Thanks !!

[cweeden 58]

Whilst idly surfing and looking for ideas for projects that I can put on a shelf and never get around to.

I came across this thread https://www.lotustalk.com/forums/f164/esprit-v8-coil-plug-conversion-77429/ and it makes the interesting comment in the opening paragraph "Idle is much smoother, fires on the first crank, zero high-RPM miss".

It makes me wonder if the coils could also be an candidate for issues?

The article is interesting, it seems to use an MW Ignitions Pro 14 CDI unit and AEM coils. The Pro 14 is a 4 Channel CDI so maybe there are two of them or the setup is driving a two sparks per channel and wasting one??

The other slightly alarming issue if the MW Ignition documentation states that you should never use AEM Pencil Coils with its controller.

See page 6 https://www.mwignitions.com/pdf/Pro-14 S3 instructions.pdf. I wonder if anything went bang?

cheers

-Chris

[swindon_alan 1,648 1 Vehicles]

An interesting thought from @mike_sekinger, a dodgy alternator dragging the volts down when the car is running. This might be an other cause of the problem if it only happens when the alternator is warm? A test would be to check the battery volts with a cold non running engine and then when it is warm before turning the engine off and incurring the hot start condition.