30 replies to this topic

[pete l]

Hi all,

 

Here is a video of my MPI trying to start.

 

Sorry about the shakes, my arm was resting on the door frame.

 

Any help appreciated, I need to get this thing going.

 

Thanks.

 

Pete.

 

https://youtu.be/y5L-6knNqUE

 

 

[Steve220]

Hi Pete, that sounds like me like fuel mainly as its trying. Are there any metal fuel pipes crimped at all? What condition is your fuel filter in? How old is your fuel pump?

[pete l]

Nothing is squashed, fule is going through the orange tube, but nothing in the green tube (return to tank) 

 

The filter looks good from the outside   might change it so see

 

The pump is as old as the car, 20 years. 

[Steve220]

I think I should have explained myself a bit better - how many miles has the car got?

Is the vacuum line attached to the top of the fuel pressure regulator.

[pete l]

the car has either done 47000 kms or 147000 kms. It's had a rebore so i reckon 147000 kms

 

Yes all pipes on and none are split.

[mpialan]

Are you sure you are getting Fuel Pumping?

[pete l]

There is definately fuel coming from the injectors, they are wet. 

 

Tuesday, only one of the injectors was wet, the other one was blocked closed. That has now been freed off and is also now wet, so fuel is getting there, but I don't know if it is under enough pressure.

 

The green return pipe to the fuel tank is dry, i don't know if that means anything or not, when the ignition is on, the pump only primes for about 2 seconds max. Not enough in my view to get the pressure up to 3 bar.

[Steve220]

I'm thinking your injectors are knackered, especially if you've had to 'free' one. If they've stuck shut, then it will have been through contamination, i'd be thinking they'd need ultrasonically cleaning or replacing.

[cian]

Are u getting spark?

[pete l]

Yes spark is fine, tested on all four leads, and all four plugs.

 

The injector was stuck shut because it hadn't been used for about 4 years. Not dirty or contaminated etc. They both open when powered and close when not powered. When open i can blow through them, when closed i can not.

[Steve220]

Pete - does your stepper motor operate when you turn the ignition on?

[pete l]

Yes it does, and when i turn it off

[Steve220]

ok. Hmm. Running out of ideas now. I'm still adamant its fueling.

Fuel pump primes
ICV adjusts itself
Car turns over with spark yet fires occasionally (doesn't start)
Fuel filter ok
Fuel pump believed to be ok.
Injectors are free operating.

Something doesn't add up. Have you double checked all sensors? Crank and cam sensors correctly plugged in?

[pete l]

I'm with you on this, i think it's a fueling problem too. I don't think there is enough pressure.

 

I have checked and double checked all plugs on all sensors yes. 

 

I have no idea if a faulty sensor would do this. 

 

I always thought a crank sensor either worked or didn't work i never thought they could kind of work but not correctly, i might look into that too.

[pete l]

Re watching the video again I see a backfire during cranking. There are other backfires in the video but always at the end of it's attempt to run.

 

A backfire during cranking would mean what ? ignition timing out ? 

 

How does the ignition timing work on an MPI ???