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Technical Problem: Cinq Sport .899 fuel pump intermittently working??

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Technical Problem: Cinq Sport .899 fuel pump intermittently working??

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chuckleberryfinn

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Hello - I have a 97 Cinq 899 that I'm trying to sell, but I have a problem. I was driving this car for 4 months, and now and again 'specially at high revs the engine would stutter, coincide with the injector warning light. Once it totally lost revs out in the boonies - thought the sheep would get me :eek:. However it started again and I was on me way. It went along like that for a month, then it wouldn't start one day after I drove it awhile. The engince turned over, it had spark, but there was no sound from the fuel pump, which can always be heard in these cars as a whir when you turn the key once. I was thinking myself I have a dodgy pump that’s intermittent. A day or two later it was working again.
I posted previously here and got a reply that the TDC sensor might be the problem. If that is the problem, would I still get spark and would the engine still turn over?
At the mo' I'm driving another Cinq that I could sway out the TDC with as a check to see if it's the problem before I buy any replacements. Another post from the mechanical wizards out there in this forum to get me on my way, and I would be grateful -day off today – it’s a car day!
 
Before you suspect the submerged fuel pump in the tank you should consider replacing the fuel filter located under the vehicle. This filter protects the the injection system from dangerous tank sediment that builds up in the filter over time. If the filter is restricted this would account for your fuel starvation at higher revs.

The next thing I would consider is the breather hose valve that is fitted under the fuel filler neck. Poor operation of this valve can cause air locks within the fuel system resulting in the engine cutting out and restarting after a short while.

After ruling out the above I would check the charcole canister is not filling up with fuel because of a faulty one way valve, purge valve, and or floats.
 
I was under the impression that the TDC was already being taken up as stated in the post and is good advice. The fuel tests I suggest cost nothing more than a filter (scheduled service interval) and a little breath by blowing into the one way valves and a some time.

Checking the wireing as stated is always very good advice and should be done as a matter of course in all cases.

Fuel pumps are usually quite robust but trickier to test without seeing a waveform from a scope to look for commontator surface flat spots. A scope can also test other sensors such as a TDC; unfortunatly without such a scope a process of illinination is the only other course of action.
 
fingers99 said:
I would swap out the TDC sensor first. Also, check the wiring to it very carefully: often it's not the sensor itself, but the wiring!

Point is not that your issue may be simply fuel related, but the odds, historically, favour the TDC sensor, by a long way.
Click to expand...

Alright I will try to swop out the sensor - thx for the assist fingers99..
 
fingers99 said:
I would swap out the TDC sensor first. Also, check the wiring to it very carefully: often it's not the sensor itself, but the wiring!

Point is not that your issue may be simply fuel related, but the odds, historically, favour the TDC sensor, by a long way.
Click to expand...

Even though the car has been sitting around a few days, there was no way it was starting. I tried wiggling the TDC, and the TDC wiring to see if I could get an indication that it was faulty (the wiring is quite difficult to get at - is it easy to swap it out??) Either the TDC was completely shot (like Fingers 99 mentioned) or it was something else, so I took a peep down where the pump is under the back seat and gave the top a slight knock to see if I could check if it might be a fuel related issue and not TDC, like a blockage stopping fuel or some issue with the pump. When I gave the top of the pump a wee tap and turned it over I could hear the pump working and the car started.
I'm just learning car mechanics at this point, so It would be really helpful if someone could indicate if it still could be the TDC or if I am looking at something else. Nought was working before I tapped the pump lightely, which would tell me that the TDC sensor is not the ONLY problem (following the logic). I have not taken it out for a drive though, I've just been starting it and running it for 5 mins each day as it's a heathen of a job to get the car back when it's stuck 5 miles up the road :eek:, but it starts no problem.
 
Last edited:
spedo said:
Before you suspect the submerged fuel pump in the tank you should consider replacing the fuel filter located under the vehicle. This filter protects the the injection system from dangerous tank sediment that builds up in the filter over time. If the filter is restricted this would account for your fuel starvation at higher revs.

The next thing I would consider is the breather hose valve that is fitted under the fuel filler neck. Poor operation of this valve can cause air locks within the fuel system resulting in the engine cutting out and restarting after a short while.

After ruling out the above I would check the charcole canister is not filling up with fuel because of a faulty one way valve, purge valve, and or floats.
Click to expand...

If you saw my recent post, I am trying to pursue the fuel side of the problem before I swap the TDC, since when I was trying to start it by wiggling the TDC and cable with no response, I tapped the top of the fuel pump, and I've heard it whir starting, and the car has been starting each time. I doubt the problems been solved. My question is if a blockage in the fuel filter would lead to the electrical fuel pump not working? It seems to me that an electrical anything has just an on/off functionality that would not be affected by a blockage, even though it would not pump due to a reverse pressure. Whenever the car has problems like cutting out when I'm driving the fuel pump does not work afterwards, and it's easy to tell since it's such a distinctive whir in these .899.s. Currently I'm learning car mechanics so I do not understand alot and would really appreciate some theory if anyone could fill me in - Thanks.
 
Fingers is correct about the TDC, however the fault you have raised looks towards a fueling problem as a more likely cause. Firstly and as a matter of course I would replace the fuel filter, if a blockage in the line or filter is detected many pumps will open a pressure release valve at 7 bar or above and release fuel back to the tank, your filter could be as old as the car. You have already started the diagnostic process and identified some sort of intermittant fault with the fuel pump.

1. Double check the security of wire connections to the pump.
2. Ensure ignition is switched off, disconnect the relay multi plug harness in engine bay (just above the ECU) and place a switched wire between pin 5 and 8, pull the switch to make contact and the pump should run continualy, if not check pump fuse.
3. Still no joy, then check inertia fuel shut off (IFS)
4. If IFS ok check for battery voltage at the pump.
5. If voltage at the pump ok suspect the pump itself.

The above info is for the Cinq sporting, other types of cinq support a fuel relay. Pull out the relay and put a switched wire between socket 30 and 87 to continually run the pump.

Ok you have checked all the wiring components, and everything now points towards a faulty fuel pump.

The fuel pressure from the pump must be able to maintain constant pressure of around 3 bar. If the brushes or commontator components are worn you will get intermittant pump operation.

You bigggest clue to this problem is the fact that a tap on the fuel pump has sparked it into life. Leave access to the pump and take it for a test run, if it stops give the pump another tap and if you start it will confirm you suspiscion.

Then a trip to the scrappy for a replacement.

Hope this helps.
 
spedo said:
Fingers is correct about the TDC, however the fault you have raised looks towards a fueling problem as a more likely cause. Firstly and as a matter of course I would replace the fuel filter, if a blockage in the line or filter is detected many pumps will open a pressure release valve at 7 bar or above and release fuel back to the tank, your filter could be as old as the car. You have already started the diagnostic process and identified some sort of intermittant fault with the fuel pump.

1. Double check the security of wire connections to the pump.
2. Ensure ignition is switched off, disconnect the relay multi plug harness in engine bay (just above the ECU) and place a switched wire between pin 5 and 8, pull the switch to make contact and the pump should run continualy, if not check pump fuse.
3. Still no joy, then check inertia fuel shut off (IFS)
4. If IFS ok check for battery voltage at the pump.
5. If voltage at the pump ok suspect the pump itself.

The above info is for the Cinq sporting, other types of cinq support a fuel relay. Pull out the relay and put a switched wire between socket 30 and 87 to continually run the pump.

Ok you have checked all the wiring components, and everything now points towards a faulty fuel pump.

The fuel pressure from the pump must be able to maintain constant pressure of around 3 bar. If the brushes or commontator components are worn you will get intermittant pump operation.

You bigggest clue to this problem is the fact that a tap on the fuel pump has sparked it into life. Leave access to the pump and take it for a test run, if it stops give the pump another tap and if you start it will confirm you suspiscion.

Then a trip to the scrappy for a replacement.

Hope this helps.
Click to expand...

Thanks Spedo, massive explanation of what needs to be done. Now I have more of an idea I can get a battle plan together, see what I can and can't do and I've a friend who's a back yard mechanic and with his tools and knowledge, we should be able to suss it out some more. I'm off to Portugal this week and won't get much done before Xmas though.

Rallycinq, you say one of these pumps aren't going to be cheap? Do you know off the top of your head what I would be looking at for a 2nd hand pump in the UK? I'm in the south of Ireland, and probably since there is less of these models around, a second hand pump would be more expensive. Of course got to add for the price of currency conversion and shipping rather heavy goods from UK to Eire. Which could add €40.
Thanks for your help.
 
Just a couple more questions Spedo. My car is a Cinq S, yet it has the relays behind the ECU which control to quote from the wiring diagrams in the Haynes Manual - Fuel Injection Main Relay and the Fuel Pump Relay, though its covered with one fuse a 25A, not two separate fuses like in my other Cinq. Thus I deal with sockets 30 and 87, and put a wire across these? 2nd question, looking at the Haynes manual there is mention of the Inertia Fuel Cutoff, but no directions as to where it is - can you tell me where it is?
Thanks.
 
chuckleberryfinn said:
Rallycinq, you say one of these pumps aren't going to be cheap? Do you know off the top of your head what I would be looking at for a 2nd hand pump in the UK? I'm in the south of Ireland, and probably since there is less of these models around, a second hand pump would be more expensive. Of course got to add for the price of currency conversion and shipping rather heavy goods from UK to Eire. Which could add
Click to expand...

Once you are 100% convinced its the pump, pm me.

The pump ain't that heavy

Cheers

PD
 
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