Auto Gearbox - under 2000rpm jerkiness

[g8dhe]

When you said before that you can see an arc at night, do you mean an actual white/yellow/red spark or just a blue glow like this picture;

If its like the above that's NOT a spark but what is called a Coronal Discharge and yes you may well see that its not usually very bright at all but it sort of proceeds a spark as it were but can't form into a spark because it can't break down a sufficient length of air to another metallic surface, sometimes known as St. Elmo's fire. You may be able to reduce it by cleaning the affected areas but down under the engine it won't stay clean for long!
A spark will be more like this a lot less blue content and a lot, lot brighter;

[New Forest Terrier]

Have you checked the distributor cap. There is a carbon rod inside the cap which wears down with use. If badly worn or possibly totally used the spark can still jump in good conditions, but starts giving problems once autumn damp conditions set in.

Last year I had starting problems on damp or misty days caused by this. Same time of the year and a real pain to find. Checked everything else before I found it.

Hodges Autolec in Bevois Valley, Southampton are very good on Bongo electrics. They do all the electrical work for Budget Bongos and most other Bongo specialists round here.

[Bongo Virgin 2]

Tum te tum. New Dizzy cap and Rotor arm fitted. Cold misfiring gone but when the engine is warmed up and under 2000rpm the same, apparent, ,misfire kicks in. Now definitely back to thinking baout the Injector cleaner but I think I'm going to take it to the garage in Ringwood that has been recommended. Can't be standard electrics so we'll see.

[Bongo Virgin 2]

Further update:
Bongo now at HDM in Ringwood. They seem very good and think they've narrowed the problem down to the ignition module but I'm having trouble tracking one down. Anyone got any suggestions?

[Bongo Virgin 2]

Humbug!!

I still have a misfiring Bongo and am wondering if anyone has any other suggestions that might be worth pursuing. HDM have had the Bongo for about 2 months and have been steadily working through things but each time they try something the fault persists. The ECU has been tested, the Ignition control module replaced, Lambda Sensor and Engine temp' sensor. Various gaskets etc checked with no faults.

They are now looking at getting it hooked up to a Ford/Mazda diagnostics to see if that sheds any light.

I can't help but still wonder if the injector cleaner did anything but the Fuel Filter and pump are all performing fine.

The fault is still the same with it performing beautifully for about 20 minutes until warmed up and then it misfires dramatically. Emissions are perfect before the misfire then go bonkers, as you'd expect, when the misfire starts.

If anyone has any possible suggestions, however ludicrous at this stage , I'd be most interested. Whatever changes when the engine warms up could be at fault but equally, thermal expansion or increasing pressures could be to blame.

Thanks for reading on.

[flossie]

Hi I've been getting something very similar for last couple weeks and it went in to Discount Trucks yesterday. Late this afternoon Fred called and after discussions he is going to try yet another sensor in the morning if that cures my issue I'll report back asap for u to try the same!

[Cosmic Bus]

Injector cleaner .... In a petrol engine?

Do you mean redex type carb cleaner or is this something chucked in the tank? I obviously haven't looked up the STP stuff yet.

Fuel related then?, still doesn't explain the arcing though. It's amazing what a small arc can cause problem wise and after my own experiences years ago, being young and driving through fjords or whatever, checking at night is the 1st thing I'd do for a misfire.

That being said, there isn't a pipe nearby spraying a fine mist nearby so it's getting damp and drying off when engines warm?

Just a few ideas to chuck in the mix

[rita]

Injector cleaner .... In a petrol engine?

Do you mean redex type carb cleaner or is this something chucked in the tank? I obviously haven't looked up the STP stuff yet.

Fuel related then?, still doesn't explain the arcing though. It's amazing what a small arc can cause problem wise and after my own experiences years ago, being young and driving through fjords or whatever, checking at night is the 1st thing I'd do for a misfire.

That being said, there isn't a pipe nearby spraying a fine mist nearby so it's getting damp and drying off when engines warm?

Just a few ideas to chuck in the mix

Hi,This type of engine is fuel injection with injectors(No Carb).

Cheers..

[flossie]

My issue causing similar jerking but not the arcing has proven to be the temperature sender unit. Just thought I'd mention it as something to rule out ...

[Bongo Virgin 2]

Thanks for the replies. The STP cleaner is for injectors but is a full bottle shot rather than the Redex which you do in measured additions.

The Arcing now seems fixed and was almost certainly lead related. The problem I have now is still exactly the same though.

Thanks for the temp sender unit suggestion. I have a feeling it has been changed on mine but will double check!

Happy days.

[Bongo Virgin 2]

Got to love cars!!
The Bongo has been in the garage for nearly 6 months and is still exhibiting the same symptoms and the garage is running/has run out of options. The ECU, Fuel ECU, Engine Temperature Sender Unit, Lamda Sensor, Dizzy Cap, HT Leads, Plugs, Rotor Arm, Coil, Intake manifold, Fuel Pump, AIr intake valve have all been either checked or replaced. The Fuel tank has been drained and the fuel filters have been checked. I think some other things have been done but I have lost track.
It's looking like I'll have to take it back and either take it somewhere else or work through things, whatever things??, myself.
Does anyone have any inventive ideas to check for to cure this problem as I want my baby back!!

The symptoms are still the same. It runs fine from cold and then after the cooling fan has cut in and out about 3 times it starts to jerk/misfire/over fuel severely to make it undriveable. It used to be that if you could use road speed to get the engine revs over 2000rpm that it would drive fine but this hasn't been chekced recently as it's been running in the garage, stationary.

Due to its specific link to engine revs and heat of engine you'd expect it to be sensor related but they appear to have all been checked. Are there any extra ones?

Anyway, any suggestions, however odd are probably worth considering.

Thanks

[francophile1947]

Probably talking rubbish, but do distributors still have advance/retard weights in them, or is it all done via the ECU? (haven't looked at one for many, many years ) It sounds as if your ignition may not be automatically retarding when the revs drop below 2000

[Bongo Virgin 2]

The ecu has been away for testing and came back all clear. They don't test them under load though. Not sure about the distributor retarding but I guess it's built into the ignition system.
Thanks for your thoughts...it's a real foxer!

[mikeonb4c]

The ecu has been away for testing and came back all clear. They don't test them under load though. Not sure about the distributor retarding but I guess it's built into the ignition system.
Thanks for your thoughts...it's a real foxer!

Where are you based? Is your garage a Bongo specialist? Might be worth trying one if we can locate one nearby to you.

[Bongo Virgin 2]

I live in the new forest. The garage I've been using have bongo experience but they probably wouldn't describe themselves as specialists. The fault does limit the distance I van easily travel.