mattie170

Hi all,

Just wondering what controls the fuel pump to prime when you first turn the ignition on. Mine sometimes primes which then it starts straight away and then when it doesn't prime it takes more turning over to start.

Cheers

Matt

martysmartie

iTrader: (1)

The CPS, the fuel pump won't neccessarily always prime depending upon temperature.

Martin

mattie170

Whats the cps? I know something is faulty as at times you can turn it over for ages and it won't start. Then other times i hear the pump prime and it starts at the first compression.

Cheers

Matt

mattie170

Oh is it the crank position sensor...

martysmartie

iTrader: (1)

Correct.

Martin

mattie170

So the data goes from the cps to the ecu then the ecu tells the pump to prime via the relay. I'm starting to think my ecu is faulty as the car has a boost issue as well. It doesn't give full boost so only produces 185bhp. Everything has been changed and checked so started to think it was electrical. Also seeing that the amal valve works off the same curcuit as the fuel pump relay does this sound possible to other people??

(The car is in standard form apart from a magnex exhaust with 3" tail pipe)

Cheers

Matt

martysmartie

iTrader: (1)

I doubt it's that serious, yes the fuel pump primes from the CPS signal dependant upon temperature as well, if it's a warm start it may not prime as it is not considered neccessary, It should prime after being left over night.

Easy way to test if the valve is working is to listen for a 'Click' when ignition is switched on but of course if the pump isn't priming then the amal won't be live.

In this case when engine is running remove the electrical connector and either listen or put a finger on the valve it should give a noticable click.

The ISCV also gets it's feed from the fuel pump relay.

Do you know what boost your running? Standard boost is 0.7/0.8 BAR.

Have you changed the CTS (Coolant Temperature Sensor) these go out of range after a while so it's worth changing as this is an important input.


Martin

mattie170

The amal valve is live and it has been changed for a new item a couple of years ago. The ISCV has been changed so has the charge air temp sensor and the coolant temp sensor. It hits about 0.7 then drops off to below 0.6. All ford information i have read say it should be 0.8. This was proved when put on the rolling road as it only produced 185 BHP and the boost readings were the same on their gear as on mine.

I have disconnected the amal before and set the boost pressure on the actuator and it was able to hold it there and the car felt loads quicker.

Other than being down on power and messing about with starting it runs perfectly. It has only done 71k. Head gasket was done a couple of years ago (about 1500 miles ago) and all compressions are about 155psi. The car is kept in a climate controlled garage with other cars so couldn't ask for anymore. It's just annoying me alot now.

Any other ideas?

Cheers

Matt

tabetha

Have you done a fuel pump rewire and a fan rewire ?, both essential on a cossie.
Both easy jobs that can save your car, may need to go somewhere that has the software to get into the ecu to see if there is a ecu problem, but more likely just a dodgy joint.
Next time when it doesn't start move the CPS connector around a bit, the female/loom side of this connector loses it's grip on the male end pins, but this would normally show up driving also, not always though.
tabetha

martysmartie

iTrader: (1)

Maybe the MAP sensor although unlikely, this tells the ECU info on the pressure in the inlet manifold, if this is giving a faulty reading then this may be causing both the problems. You can test them if you know the voltage to pressure scale.

Martin

mattie170

I haven't rewired the fans or pump. I want to try and sort the problems I have now before rewiring other bits.

I have had the ecu read before but nothing. Its not the fact it doesn't start, it can just take a while turning over to start but once it runs its perfect apart from being down on power.

As I said sometimes the pump does prime but not very often. I can't see the cps being faulty as it runs fine when started unless you tell me otherwise!!!?

The boost issue is really annoying and i'm at a dead end with it, I have run out of idea's!!!!!!

tabetha

If the prime function of the ecu is lost, the easiest way would be to simply wire it through a changeover relay using the negative of the oil pressure switch to switch the relay, thus it would prime everytime it was turned on due to illumination of the oil light.
Boost issue should be an easy fix, APT are only just down the road at Lenwade, 01603 870990, might get more clue on the rollers

mattie170

Yeah thats an idea would be easy and cheap to do. I will do that at last resort as I want to keep it near standard as possible.

I have already been to apt used them for years and I do work for them. Its been on the rollers there thats how I found out about the low power. Since then I have changed the actuator for a recon item,blocked the dump valve, new air temp sensor and had the ecu read and a smoke test done on the inlet......but nothing. I have also disconnected the amal and set the boost manually and the turbo can do it so that eliminates the turbo itself.

I'm thinking about taking it to MSD unless there is someone else who is very good closer??? Don't really fancy the drive up there to be honest.

tabetha

The next nearest one I know of which has the software for your ecu is SCS in peterboghorror, a lot nearer, but it would be a nice drive back from msd/blackpool area with more power I'd be looking forward to it.
tabetha

BIL N KEL

sounds like you have a bad wire somewhere. my saff had exactly the same problems as yours (eractic boost/sometimes wouldn't prime). check there is 12v going to the amal valve(mine only had 0.8v) run a wire from the -side of your coil to the live wire on the amal valve to fix this. rewiring the fuel pump is easy, i used the old amplifier wiring kit that was in my car when i got it and just ran a earth wire to a switchand i've never had any problems since

mattie170

I have been to SCS before but couldn't remember the companies name.

I'll check to see what the voltage is in the morning but I think I checked it before and it was the same as the battery. I'm kind of hoping it's low on voltage and it will sort it.

Cheers for all the help.

martysmartie

iTrader: (1)

DO NOT run a wire from the live of the Amal to earth or anything else come to that this will cause a short, especially the coil whose negative side is switched anyway!!

The only earth that should be coming from the Amal is the one back to the ECU.

Measure the voltage between the live and earth on the connector NOT the live and an earth elsewhere otherwise this will not show if there is an earth fault.

Martin

mattie170

Well before heading home I checked to see what voltage was at the amal valve and it is 12 volts. Also the pump didn't prime either and it hadn't been touched since saturday.

I think before I travel anyway I would like to see if anyone in the local area wouldn't mind me borrowing their ecu (if standard) and quickly try it out and either confirm its the ecu or rule it out. Is anyone willing or know of anyone in the local area or might be willing??? Please get in touch

Cheers

Matt