16 TRS fuel feed ??/ running fault now worse and consistent

[B-Hive]

Hi all

It's good to see that we're all still very active here on this forum..

Margot (16 TRS AUTO MK1) is as per my previous post, now registered, but seemed to suffer from the effects of a very cold winter.

In the middle of a bit of pull down right now.

Story goes ...She was running really poorly...would rev freely in neutral, take off in 1st ok then would die/loose much power under acceleration by the time she wanted 2nd.. Easing off would allow very very slow tentative progress, but as soon as ANY throttle was applied, car would totally baulk and refuse to make headway. Initially it seemed to be carb icing, but this was soon eliminated as a possibility as problem surfaced under varying ambient temps and differing states of engine temp. Problem just got worse and worse.. Just when i thought that I'd found the cause, it would occur again. Really feels like fuel starvation.

Sometimes a second start would fix the issue. Very intermittent and unpredictable.

I have checked almost every thing thus far. Fuel pump,, fuel filter,, total carb clean out/check...float level..needle valve ..etc etc.

Then she began to struggle to stay running after starting..after about 20 seconds it would need the throttle angle to be constantly changed/feathered in an attempt to keep her running. But ultimately she would cut out.

So kinda stranded in the driveway..I decided to pull off the inlet manifold and see if there was an induction leak. Gasket seems ok.. but nothing really obvious.. Pulled carb off again.. and rechecked.

If, when i put it all back together, it still acts up, I am at a total loss to know what next to do..

Is there a filter/strainer on the fuel tank pick up?. Hoping there is, as this would definitely be a possible cause if clogging. I know the diesels have one..not sure about petrol models.. no refernce to it in the Haynes

Sorry about long post but thought would get advice before reassembly tomorrow.

Fanks in advance

[jonathan_dyane]

Are you 100% sure that the ignition side of things is AOK? Assuming that the rotor arm/distributor cap/plugs/leads are in servicable condition, and that low tension wiring is in good order, I'd be looking at substituting the ignition module for a known good one.

Also I would recommend removing the drivers side wheel and turning the engine over with a big socket on the crank pulley to ascertain that there is compression on all four cylinders.

Good luck.

[jonathan_dyane]

PS, if you really want to rule out fuel supply problems, securely tie a plastic petrol can of petrol to the roof of the car, and run a length of petrol pipe from it to the carb having started a syphon action (disconnect and plug the fuel pump feed to prevent petrol pouring everywhere). Gingerly have a good run round the block to see if the problem still exists...

[B-Hive]

PS, if you really want to rule out fuel supply problems, securely tie a plastic petrol can of petrol to the roof of the car, and run a length of petrol pipe from it to the carb having started a syphon action (disconnect and plug the fuel pump feed to prevent petrol pouring everywhere). Gingerly have a good run round the block to see if the problem still exists...

.. only a fellow citroen owner would dare to suggest something as conspicuous as that test!!!

Everything reassembled and fired up...perfect ...perfect... got all excited and started to tend to trivial car things... jumped in to go to the shops... oh oh!!... its back ... having covered everything fuel side...my thoughts did turn to ignition ... heat of spark ..hence will rev until power required ...is the ignition module an amplifier as well or just a go between the dizzy and coil? if its merely a sort of control module and faulty, then I'd think it would be erratic all the time..currently no probs revving in neutral..

so thoughts have turned to coil.. and /or main ignition lead from the coil..what do you think?

I do have a spare ignition module but its out of a 90 BX19 TRI (injected) ..are they interchangeable with mine (85 carb)? if so I'll swap it out ..


Thanks again

[jeremy]

Had something on my Renault 21 - never did find it!

Check all the ignition - from the plug gaps, the HT leads - must be less than 20,000 ohms, the distributor, cap, rotor arm, module, coil and anything else you find.

Is the module which must be mounted on conductive paste - search this site and I'm sure you'll find it.

If your coils look the same they'll work. Even if there are differences it won't be noticeable at anything below about 5,000 RPM.

Does the vacuum advance unit work? Its probably best blocking the pipe to the carb if it doesn't.

The Renault was very particular about plug gaps - and wouldn't tolerate anything oversize. I gathered its problems were quite common with that engine and Volvos would suffer from the problem as well. I cured it eventually by buying a Citroen BX DTR Turbo Estate!

[B-Hive]

ARRRGGHHH!!!.

I have never before experienced a reliability issue so annoying.

I was all fire up ready to explore ignition issue. Replaced main ignition lead from coil.. Problem still there!!!

But now I am pretty sure that if I floor the throttle and open up the second barrel on the carb, the machine actually starts to make forward progress. This would indicate a problem in the primary barrel. But what sort of problem would be intermittent, jets either are clogged or not..venturi is secure ... no induction leaks...besides which I have pulled it apart and cleaned the carb pretty thoroughly, and when things are working its all very good. (and no its not carb icing!!)
I actually recently did a 700km trip no dramas and justifiably believed that I had solved the mystery issue..only to have it resurface worse than ever

Its a bit like having a ruler that more often than not draws a wonky line!!!

All the cars that I have owned with weber carbs have never had any
reliability issues ..ever!!! and ignition system should be straight forward. It seems like some voodoo curse that's testing my endurance and patience. certainly souring what has been an otherwise good relationship...

The best way I can describe the fault is lack of/nil throttle response on attempting any sort of acceleration, and as indicated above will respond if i floor the accelerator (into the second barrel)..

My next step is to hand the car over to a garage.. but most know little more than I do..and would happily charge $80/hour only to guess much the same.

[demag]

Interesting.

I think you may have given us a clue in your description.

"It revs great in neutral" or similar words.

Now, I would think if it was fuel related then the problem would be there all the time including neutral. However, some ignition problems will only show when driving. In other words the extra strain on the ignition system when actually driving along will cause it to fail. Rev it in neutral and you would think it was ok simply because there is no load on the engine.

Sometimes if you lift the bonnet at night if it is really dark you will be amazed at the stray sparks flying around all over the place! But if there is any street lighting it probably won't show.

So my vote is for dodgy ignition.

Good luck.

[mnde]

Hmm...

I've had hesitation problems with my GSA before, where the idle is fine, it seems to "rev" fine, but put the engine under load in gear and it didn't want to know. Release the throttle and tentative headway was possible, but try and press any further and it would baulk violently and almost stall... until I released the pedal again. I always put it down to a carb blockage/air-fuel mixture problem.

After a bad period last year, after trying 99 octane fuel a couple of times and the car really hating it (coincidence? I don't know) I had the carb professionally cleaned out, and it was much better (they found a blockage) - the midrange flat spot disappeared, and the sudden loss of power symptoms above have disappeared.

But more recently I made the mistake of blipping the throttle with the choke half out, and the poor running returned temporarily which was embarrassing as I was on my way to the local classic car show with my girlfriend .

Anyway, this 16TRS Auto. Have you checked the ignition timing, the operation of the automatic choke and what octane fuel are you running?

Cheers,

Mark.

[B-Hive]

Thanks for all your input.

I thoroughly cleaned carb again, and in process of reassembly noticed a ridiculously conspicuously loose wire on the coil. I had checked here before !!! ...but there you go... after reassembly ..shes all perfect again and a joy to drive.. there was nothing really substantially dirty in the carb so in all reality, I have to put it down to this wire.. i have learnt that ignition system have more of an impact on acceleration/load than fuel/carb. Still strange how it seem to respond to second barrel of carb being opened ..which for all money seemed to point to fuel/carb problem

Margot doesnt know how close she came to being moved on.. but it must have been a test of tough love!!

Again thanks for everyone's advice[/b][/u]