Falcon's Bargain Basement Motoring

[NewcastleFalcon]

A useful diagram Neil, I still wonder if my earlier suggestion may be a possibility re intermittant loss of fuel pressure. A pinhole in the vapour pipe may also cause an occasional blip in manifold/rail pressure?

Thanks Mick, your suggestions have a good track record, although I have pretty much lost all enthusiasm for the under car crawl inspecting the full length of the fuel pipe. I know the fuel pipes are not contemporary with the 23 years of age of the car. They were replaced within our ownership so when all else fails I may get someone to have a look. Even a pinhole is going to produce noticable spray and a precise-ish "niff" area. The dodgiest bit of the set up is the map sensor which moves. and is quite insecure in its hole in the air intake manifold and according to Clio aficionardos "needs sticking down!" One of those is on order.

The Clio likes a bit of plastic. This is hidden behind the front right wheelarch liner and I think its number 6 in the diagram even though it is placed at the rear in the diagram and its actually at the front of the car.! Don't think that or its pipework is the cause of the hesitation power loss stutter then instant-ish is recovery to full power experienced from time to time.

The 23 year old injectors clearly work fine when the temporary blip in power/hesitation/stuttering is overcome, and the engine has as much poke as the day it came out of the factory, absolutely nothing to complain about on the power front when the stuttering is overcome!

I think we need this thread to come to a positive conclusion, yes for my own selfish reasons and a niggle which to be honest doesn;t actually require to be resolved but for a desire not to leave an unsatisfactory puzzle not solved! So many threads on the Renault forums and in many other forums on the subject of these intermittent but regular hesitations. stutters blips, flat spots and misfires turn into unresolved sagas! We need a success!

Neil

[NewcastleFalcon]

Oh look Schrodinger's Cat has arrived in its little Green Box!

Neil

[mickthemaverick]

I'd be wary of using that Neil, it may have been involved in Star Wars

[CitroJim]

Neil, I can confirm from personal experience that even the tiniest of pinholes in a fuel line will give itself away with quite a spray and concomitant aroma...

A rodent once gnawed a fuel line on Robyn's 207 many years ago. It was very obvious...

[NewcastleFalcon]

Neil, I can confirm from personal experience that even the tiniest of pinholes in a fuel line will give itself away with quite a spray and concomitant aroma...

A rodent once gnawed a fuel line on Robyn's 207 many years ago. It was very obvious...

I dont know if you have read this from the start Jim, but I am sure that over your DIY mechanic-ing experience you will have come across the car which hesitates and stutters then with a decent bit of right boot, picks up again and powers away as normal.

I think straight away "temporary fuel starvation" rather than any o2 sensor caused fuel trim malfunction. I seem to recall you had a bit of a "potentiometer" problem with one of your "named vehicles" ( ). I really dont think that's it in my case either with the throttle body or the Accelerator Pedal position sensor. It revs freely through the range when the stutter is "inactive"

In the days before sensors and widespread fuel injection systems I recall hitting the Electric Fuel Pump at the rear subframe of my mini with a hammer often jogged the beast into action again!

I would appreciate your observations Jim

Thanks Neil

[CitroJim]

I dont know if you have read this from the start Jim, but I am sure that over your DIY mechanic-ing experience you will have come across the car which hesitates and stutters then with a decent bit of right boot, picks up again and powers away as normal.

<snip>

I would appreciate your observations Jim

I will take a close re-read of this Neil and then see if there's anything useful I can add. I doubt I will be able to but let's see

And yes, I have memories of whacking an SU electric pump with a hammer to persuade it back into life And also starter motors in a similar fashion!

[NewcastleFalcon]

I will take a close re-read of this Neil and then see if there's anything useful I can add. I doubt I will be able to but let's see

Thanks Jim. Nothing in depth required, just wondered if you had any cures and fixes from similar problems in your motoring experiences!

As mentioned one of my Xantia turbo diesels had stuttering/hesitation which was "fixed" with compressed air down the return fuel pipe if I remember correctly, and one of the Sierra diesels with a new accelerator cable, and a Mini Metro a condenser!. The Clio neither has a return fuel pipe or a proper cable from accelerator pedal to throttle, and points and condensers are long gone!

All the fuel supply gubbins from petrol tank, to in-tank petrol pumps, to filter, to petrol pipes, to fuel rail, to injectors fully available at individually not too bad prices, but as a whole much more than the car is worth, either in monetary value or in the satisfaction of a fix for me!

Neil

[mickthemaverick]

Your mentioning of the compressed air blow through the return pipe reminded me of the fun and games I had with the 1.8 HPi C5 I had. That problem turned out to be fuel vapourisation in the fuel pump resulting in an inability to exceed 3000 rpm. After many trys and fails of replacing various parts I cured it in the end by adding a fuel cooler from a diesel return line to the feed to the petrol pump. That worked and I assumed it was simply because the cooler fuel entering the pump was not vapourising and hence allowing full use of the engine. In hindsight I seem to remember the fuel pump was mounted in a dumb place where too much engine heat was soaked into its carcass and hence it only needed warm fuel to start the vapourisation issue. Just a thought!!

[MattBLancs]

Neil, has your new MAP sensor been installed as yet?

[mickthemaverick]

Quite right Matt, no idea why I put 1.8!! Here's a picture of the beast!!:

MTMO

Sorry Matt, I seem to be having a bad day, in attempting to quote your post I seem to have deleted it!! No idea how I did that either, maybe hit edit instead of quote but it's gone, good job it was only affecting me really

[MattBLancs]

Ha ha, no worries Mick!

For completeness, I said something like:

Oh that's rare Mick, but not a 1.8. don't think I've seen an EW10D equipped car in the flesh. PSA jumped on the direct injection bandwagon (too??) early.

[NewcastleFalcon]

Neil, has your new MAP sensor been installed as yet?

There is a little bit of jeopardy with the MAP sensor, which may well have been in place for 23 years. It is easily broken and bits can fall off it on the removal process into the inlet manifold. Then there is the Schrodingers cat phenomenon, the replacement MAP may or may not reveal a living "cat".

While the two possibilities exist there can be a period of optimism that the replacement sensor could produce a living cat.

A reply of "eh?" would be understandable Matt and the short answer to your question is "No I haven't installed the new MAP yet! I will of course, but I will pick my moment. It may be after taking the plunge and removing the inlet manifold and seeing what is revealed, and has the advantage that any potential breakage of the old MAP could easily be retrieved.

I am not that convinced it's the whole problem, but may contribute to it. I think fuel delivery from pump to filter to rail to injectors is the leg of the system most likely to be responsible for the hesitation/stuttering than back to full power.

Plenty vids on injector testing and cleaning and refurb with new seals and their tiny little filters..inlet manifold needs removing to get access to them anyway.

Neil

[MattBLancs]

Ahhhh, with you on the mention of Schrodinger's Cat now!

Yes good plan to take the inlet off (for cleaning) and gave the bonus of catching any MAP shrapnel in the event that goes awry!

[NewcastleFalcon]

There's more to this cannister thing than meets the eye. I thought it was just a passive thing, various tubes from various places connecting into some sort of chamber but it incorporates a solenoid operated valve...which clicks...in the BB Clio's case even after switching off. Thought the clicking was something to do with the AC but no, it is this valve/cannister mounted behind the offside Headlight bahind the wheel arch liner.

The solenoid valve in a Renault Clio 2's canister controls the flow of fuel vapour, allowing it to be purified and preventing it from being released into the atmosphere. It operates by opening and closing to regulate the vapor entry into the carbon canister, which cleans the vapour before it's released.



and...according to internet wisdom, symptoms of a failing carbon canister in a fuel-injected engine include a noticeable fuel odour around the vehicle, a check engine light activation, poor engine performance, reduced fuel efficiency. Some ticks there as well as the actual ticking of that solenoid valve.

Neil

[NewcastleFalcon]

A little run has ticked the BB Clio's milometer past 85,000 miles.

No interventions by me as yet apart from one...

The return journey threw the stuttering up when under load up a hill, picked up but that little stutter did put on the P0130 code.
Cleared it when stopped at home, and when stopped ("ignition off") that EVAP valve solenoid was clicking away for a minute or so with everything switched off. Probably an aside but after 23 years of "purifying" the vapour emissions and discharging them, I imagine that the carbon canister is not what it was when the car exited the showroom in 2003. Probably an aside...

...anyway back to the Falcon intervention. I call it "The Laying on of Hands", in particular to the wiring loom going into this thing. A smoothly running but fluctuating revs idling was returned to a smoothly running idling by the laying on of hands to the wiring bundle as it entered the steel "security cage" which Renault deemed necessary to make it difficult to tamper with the ECU.

Neil