205 1.9 Difficult To Start, Please Help

[stevessub 0]

I have owned a 1.9 cti 105bhp model for 7 years and only comes out in summer, My Problem is it will start from cold with no issues but as soon as ignition is switched off it refuses to restart unless I disconnect the fuel relay to stop fuel and while cranking then when it fires up quickly plug fuel relay back in, has anyone got any ideas what this could be,

[dcc 855]

when you try to restart does the fuel pump prime?

 

and does your starter motor turn the engine over OK or does it click?

 

and do you have any form of an immobiliser?

 

what reg is your car? is it CAT / Lambda equipped?

[stevessub 0]

cant really hear pump prime but pump is defo working

 

starter motor is fine, cranks engine over good

 

I removed the alarm system thinking that was the cause

 

Car does have a CAT/lambda sensor

 

hope his helps

[PhilNW 43]

Do you have

 

a decent spark?

 

petrol getting through?

 

Does it not start when hot or cold ?

 

Could be the relay if it restarts after unplugging and reconnection

Edited June 2, 2014 by PhilNW

[stevessub 0]

I have good spark

 

petrol is getting to fuel rail

 

starts easy when cold not hot

 

I've tried a replacement relay

[DamirGTI 342]

Leaky injectors possibly .. get them tested on ultrasonic machine for leakage , also while on the machine for blockage/spray pattern and clean them if there's erratic spray pattern (even if this doesn't solve the hot start issue it'll be of the benefit for the engine performance and reduced fuel consumption .. when you find and fix the starting issue of course)

 

If not injectors then could be fuel pressure reg. or fuel pump - plug up the gauge and measure fuel pressure in order to see what's happening with the pressure with the engine running and with the engine shut down ...

 

D

[stevessub 0]

Today Ive replaced the lambda sensor and another new ecu temp sensor and still same issue, tested the coil in case of a weak spark and it tests perfect with a good strong spark, whilst the plugs were out i noticed a lot of fuel coming out the cylinders, more than i would expect for it starting so it defo looks like its overfueling, just been on ebay and ordered a replacement ECU to try, failing that then could it be the AFM even tho it tests ok and is very lumpy running when disconnected My AFM is part no 0280202097 are they interchangeable or do I have to buy the same model.

been quite a new 205 the haynes manuals are not really that good, I also have a strange looking filter under nearside front bumper , anyone know what this is,

Edited June 4, 2014 by stevessub

[dcc 855]

Do you have a spare tachometric relay to try? I am not sure how it would, but it's possible the relay is sticking?

[stevessub 0]

Yes I have tried a spare and same issue. even tested all the components inside and values are good

[dcc 855]

sounds like a voltage drop then if its only when warm. check your earths for the ECU, battery to chassis and battery to engine.

[Tom Fenton 1,539]

Symptoms sound like ECU water temp sensor, have you continuity tested the wiring from the sensor back to the ECU?

After that my money would be on the airflow meter. I have had one fail such that the car was over fuelling massively. When the engine is cold the extra fuel is like cold start enrichment that should be there so it copes OK. However when hot it's too rich which is why it won't start as it's probably flooding it. Pulling the relay means the fuel pressure drops off which has the effect of leaning it off enough for it to start up. The relay is working fine.

I would expect the tailpipe and plugs to be black and probably a strong smell of fuel and some black smoke out of the back!

[stevessub 0]

Symptoms sound like ECU water temp sensor, have you continuity tested the wiring from the sensor back to the ECU?

After that my money would be on the airflow meter. I have had one fail such that the car was over fuelling massively. When the engine is cold the extra fuel is like cold start enrichment that should be there so it copes OK. However when hot it's too rich which is why it won't start as it's probably flooding it. Pulling the relay means the fuel pressure drops off which has the effect of leaning it off enough for it to start up. The relay is working fine.

I would expect the tailpipe and plugs to be black and probably a strong smell of fuel and some black smoke out of the back!

 

Thats exactly whats happening, but tried 2 ecu water temp sensors and same issue. have even unplugged ecu temp sensor whilst running and it runs poor, so continuity should be fine, the plugs are fouled along with tailpipe. Trying to get a AFM for my 205 is quite difficult due to it been the 105bhp model.

[Tom Fenton 1,539]

I would check continuity back to ECU plug to make sure. The ECU's are generally reliable and rarely cause a problem. AFM would be my next course of action.

[stevessub 0]

so check continuity from AFM to ECU, do you know the colours or pin outs or any idea where to get a decent wiring diagram

Edited June 4, 2014 by stevessub

[Tom Fenton 1,539]

There is an accurate wiring diagram in the Haynes manual, if you search for user M@tt on here there is a link in his signature.

[Pugnut 9 1 Cars]

Ok, it might be 15 years or so, but I once had this problem, and it turned out to be the non return valve in the fuel pump (integral part).

 

Don't ask me why, ( might be something to do with how the fuel pump primes, or how the fuel drain back into the tank initially),I seem to remember not understanding why at the time.

 

Damir advised to monitor fuel pressures. In the absence of a gauge, the thing to do is to wait till the engine has stopped, wait 2-3 minutes then carefully disconnect the fuel rail supply to see if there's pressure still there, if not then there's the problem

 

Could be something else, but it's easy to check and rule out.

 

Al.

[stevessub 0]

pressure is still in rail after a while Ive noticed that, dont think its pump related as ive removed the return and blown down tube and you can hear air reaching tank also whilst disconnected fuel return from pressure regulator and fuel does return.

 

My car has a lambda sensor apparently there is a Lambda Fuse does anyone know where this is.

[Slo 283 1 Cars]

The fuse is for the lambda heater not the actual sensor itself. Look in the shunt box for a 10 amp fuse I think

[stevessub 0]

took injectors out today, spray pattern is good and none are leaking, still seams like a lot of fuel coming out from injector, could the fuel pressure regulator be holding to much pressure, also the fuel relay is it ment to stay on when cranking or ment to pulse on off.

[MikeC 10]

As far as i remember, the tachymetric relay will take a pulse , and hold the relay on.

[Pugnut 9 1 Cars]

The pump is either on or off iirc. It has no need to pulse since it just pumps in a loop back to the tank and the pressure reg maintains the pressure.

 

Might be worth by passing the tack relay and feeding the pump with a solid 12v and take it from there.

Edited June 6, 2014 by Pugnut

[MikeC 10]

As i was saying, the relay takes a pulse, and is held on, should have been a bit clearer

[stevessub 0]

As far as i remember, the tachymetric relay will take a pulse , and hold the relay on.

Thats what I thought, looks like mine is ok, waiting on ecu, failing that I just dont know

[Pugnut 9 1 Cars]

Sorry, i took your post to mean the feed to the pump was pulsing. Ignore!

[MikeC 10]

If you suspect overfueling, check you oil, not good to have petrol in the oil pan. How is your return fuel line, is it kinked?