Griff won't start when hot

[DEANOGRIFF]

My Griff refuses to restart when warm. It will turn over and fuel pump is working, if i remove fuel pump relay and turn over it fires straight away. It has been mapped by Mark Adams. Is it the relay playing up or maybe the pump?

[blitzracing]

Whip a plug out after it wont start and see if its wet or sooted up. An over rich mixture will flood the plugs, and stop it starting, and I suspect that removing the relay will allow the engine to dry out if no more fuel goes in. I assume it just fires then dies?

[bomb]

You may wish to fit a 'Hot start Kit'.

see here......

http://www.tvrgriffith.com/index.php?option=com_co...

[Del 203]

bomb said:

You may wish to fit a 'Hot start Kit'.

It's not starter motor related so that wont solve the problem....




For a change

[bomb]

Well the 'hot start kit' does not transform your starter motor, but it corrects the inherant fault that is due to a build up of resistance in the wiring when the engine is hot.

The resistance prevents the engine from starting.

This small change to your wiring sorts it out, and hey-presto ! - Your car starts every time.

worth a look......

[Del 203]

DEANOGRIFF said:

My Griff refuses to restart when warm. It will turn over and fuel pump is working, if i remove fuel pump relay and turn over it fires straight away. It has been mapped by Mark Adams. Is it the relay playing up or maybe the pump?

bomb said:

Well the 'hot start kit' does not transform your starter motor, but it corrects the inherant fault that is due to a build up of resistance in the wiring when the engine is hot.

The resistance prevents the engine from starting.

This small change to your wiring sorts it out, and hey-presto ! - Your car starts every time.

worth a look......

How will it solve this problem ???

[bomb]

Note to self........Read the question !!

OK, I failed to read the fact that the engine starts, but then cuts out. So its not a hot start issue.

I'll get back in my box.

[3024E]

Bosch fuel pump ???

Could be the schrader (one-way) valve in the end of the pump.

Is the pump noisy ???

[DEANOGRIFF]

No, fuel pump is quiet (will upgrade to 044 pump in future), tested amplifier, ok, replaced coil with new, disconnected stepper motor, made no change, no air leaks anywhere. Pump primes ok, motor turns over but is flooding engine for some reason. Pull fuel relay and car fires. Is ok when cold as running on cold start map. Wont start with throttle buried to floor either.

[blitzracing]

The fuel control at start up is fixed for a couple of seconds before the AFM output is measured by the ECU and the correct amount of fuel added according to the fuel map and sensor inputs. You wont actually see this happening however unless you measure the injector pulse with during start up. A failing AFM can give an over high output voltage, so the ECU dumps in to much fuel. Dont forget also just how hot the AFM electronics gets in a TVR engine bay as well. I would beg borrow or steal a working AFM as a simple test to start with.

[CHGRIFF]

Did you check the MA tune resister voltage supplied with the Bosch AFM. Was it to spec?

[Pasco]

What ever happend to Dave Beer

[DEANOGRIFF]

Update, replaced AFM with spare which is known to be ok, checked voltages on throttle potentiometer and lambdas and made sure i have 1.8v on the MA tune resistor for the Bosch AFM. All ok and it will fire straight away when warm, but only if i floor the throttle before the fuel pump primes.

[MrMCI]

I once had a similar problem on another car it took ages to find the problem but turned out to be a dicky fuel pressure regulator which was failing when hot. May be worth more investigation. Mark

[blitzracing]

DEANOGRIFF said:

Update, replaced AFM with spare which is known to be ok, checked voltages on throttle potentiometer and lambdas and made sure i have 1.8v on the MA tune resistor for the Bosch AFM. All ok and it will fire straight away when warm, but only if i floor the throttle before the fuel pump primes.

What where the lambda's doing voltage wise- idle, engine hot?

[DEANOGRIFF]

The lambdas were tested when engine was hot and at idle. They were cycling between 0v and about 1.2v. How can i check the fuel pressure regulator? I've heard that these can fail. MA changed both my lambda probes when it was mapped and has only covered about 100 miles since.

[DEANOGRIFF]

An update on my hot starting issue and no difference. It will still start when hot if i depress the throttle before the fuel pump primes. It turns out that there was another blue Griff not more than 10mins from me (the wife has heard and seen it before and promtly panicked and checked the garage).He came up to see my car and brought his code reader with him. We checked that it was working correctly and then checked the car. The good news is that it didn't show up any problems or faults with my ECU. The only thing we found was that although the coolant temp sensor is default code 14 and the fuel temp sensor is 15, when we disconnected these sensors, they registered as the other way round. The air/fuel gauge is reading 14:8 when warm. I'm still stumped and it's so annoying to be this close to having a 100% car. HELP!

[chris212]

I had a similar problem, which turned out to be the coolant temp sensor (up right one behind the dizzy cap). They can go faulty, giving incorrect info to the ECU and resulting in incorrect fuelling.
They cost about £15.Try Rimmer Bros I'm sure it was only £10 last year.

[blitzracing]

Please drop a couple of plugs out after its been idling and hot (let the engine cool obviously) and post a photo.

[EGB]

Dean. Hope you fixed your starting problem. What was it. Keep us all updated. Thanks.