gigford

Hi,

i raced my 1990 sierra 4x4 cosworth on a bumpy tarmac/gravel track yesterday and the engine cut off suddenly, could not restart it since.
The fuel pressure and the coil is ok but no spark to the plugs any more

The car is modified by the previous owner during the years for better performance, lot of dodgy wiring unfortunately, old cables, connectors so it's an electrical nightmare. All i know it has a T35, chipped ecu, standard coil and injectors, very stiff suspension.

Probably the lot of shaking the car got during the race could have caused the problem but I have no clue what to check, any suggestions would be appreciated.

There is no visible sign of broken cables or connectors but i can recheck whatever you suggest.

martysmartie

iTrader: (1)

Does the pump run, how was the pressure checked?

I would look toward the CPS, this sensor is on the crank pulley, you will see a connector, make sure this has not come loose.

Martin

gigford

Hi Martin,

there is a fuel pressure gauge fitted and the fuel pump is switch operated so when i flick it, i hear it running.
i've checked the CPS connector, not loose at all.

KSA-Cossie

iTrader: (4)

Check the gap and see if the face is clean etc

martysmartie

iTrader: (1)

As standard the pump will prime upon receipt of the CPS, this is what made me question the pressure, so it's irrelevant in your case.

Do you get a spark from the king lead (LT) i.e. the one on the coil?

Martin

gigford

There is a spark, although a weak one. I've inserted a spark plug into the king lead, placed a wire to the negative pole of the coil, turned ignition on and quickly grounded it on/off. But if i leave the negative feed of the coil on and crank the engine, there is no spark.

Results:

10) CRANK SENSOR: Check resistance between pins 3 and 4 between 300 and 1200 ohms. - There was 0 ohms between the ecu pins but when i disconnected the plug from the cps, i've measured around 700 between the plug terminals.

11) CRANK SENSOR: Check AC voltage on pins 3 and 4 while cranking engine - should be at least 2V. - This was zero...

16) IGNITION TRIGGER: Read voltage between pins 24 and 25, should be at least 4.5V. - This was only 3.75V

martysmartie

iTrader: (1)

It won't give an output without the ground connected.

Have you checked the crank sensor isn't dirty?

Martin

carl/saff

check the 3 multiplugs on the bulkhead above the rear of the camcover also check ignation amp .. crank sensor multiplug behind the dizzy, and phase sensor connections inside the dizzy ,

And check all teeth are on the crank pully , seen dodgy cambelt changes crack the pullys .

Goodluck

Toe Knee

iTrader: (2)

Was gonna say above too check the crank pulley lugs if you hit the gravel hard enough potentially could have damaged one causing problems.

I had a bolt come loose ones which chipped one, was fine till I backed off then cut out. Checked over everything loads of times then then realised what had happened!!