V6 Power Problems...help!

[BongoNog]

Being the proud owner of a V6, I took it with me when I emigrated to Norway last year. I've yet to see another Bongo in West Norway, but neither have the garages ! Hopefully someone can help...Everything was fine when we drove back to Scotland in October, however after the service at a local garage we had a very rough sounding engine and a loss of power (and a very long drive back). I suspected that the spark plugs the garage had changed were the wrong type so I changed those out and noticed that the ignition leads had been 'leaking' with burning and char marks around the spark connection. The spark plugs also showed heavy carbon build up. The power problems have since got worse, the van refuses to change down and struggles up even slight gradients, so much so its undriveable . I replaced the igniton cables and spark plugs (again) today but to no result. I'm thinking the next step is to change out the distributor cap & rotor arm, but this is getting expensive, so any helpful suggestions much appreciated! My Bongo is an 01 model SG-5W Friendee. Many thanks, BongoNog

[bigdaddycain]

Hi, And welcome.... Are you back in Norway with your bongo at the moment?

[dandywarhol]

The distributor cap seems to be vulnerable on the V6 and moisture can get into it causing the problems you describe

[manners]

Carbon deposits on the plugs can be caused by many different conditions. Carbon deposits build up when the plug fails to fire correctly and burn them off. Air/fuel mixture too rich, choke stuck on, electrical problem, extended periods of low speed driving, plug heat range too cold. All should be investigated.

[BongoNog]

Folks thanks for the welcome and tips. I'm back in Norway and it is certainly cold! I'll take the distributor cap off tomorrow and see if I can see anything (and give it a clean while I'm at it.) I'll work through manner's checklist, but outside mechanics are a bit tricky at the mo. as its -9 outside

Incidentally I got the new ignition cables from japautosolutions - pricey but genuine parts and they shipped to Norway. With regard to plugs I found the following recommendations on various makers websites for Japan..

NGK BKR5E-11 (what I'm using) or IK16 Iridium Power
Denso k16PR-U11

Plug gaps seem to be 1.1 mm, although I can't find anything to confirm this.

[Dolly1]

Are the plug leads on the correct plugs,one could be wrong. ??

[Ian]

Distributor cap is about £50 from Mazda.

[francophile1947]

Plug gaps seem to be 1.1 mm, although I can't find anything to confirm this.

That seems to be a very large gap 1.1mm is about 43 thousandths of an inch - I seem to remember plug gaps usually being around 25thou (0.63mm) - maybe times have changed cos' I haven't had a petrol car for years

[cheffy34]

Is it actually missfiring I had my leads made for £40 hyundi lantra ends for those that are interested i have a contact number he kept measurements and can nock em up the cap on mine has been prone to water ingress when driving in extreme heavy rain and standing water, water gets in and lies at bottom of cap knocking out middle cylinder on nearside bank and both end cylinders on offside back deep standing puddles hit at any speed sends water up through the scav fan on a collision course with the dizzy Thats if it water, the gap is usually the last digits on the plug aren't they i remember summit about 11 being 1.1 on the plugs, get your cap off and have a butchers mine ain't bad but original i suspect just cleaned it up, as manners says check all aspects, use this link to see what your plugs are telling you

http://www.theultralightplace.com/sparkplugs.htm


goodluck with it


Dar

[BongoNog]

Well, I took the cap off (after working out how to bend my arm enough to undo the blind screw on the bottom ) and it was dry inside, however the 2 & 5 contacts have completely eroded away. I also found that the cable configuration as inherited from the garage did not match up to the cap numbers , possibly the cause of the wrecked contacts? Give that the fuel mixture is also too rich based on the plugs, I'm not surprised at the performance

Can anyone point me in the direction of where to adjust the fuel-air mix? and which order the cables should be on the engine block? Looks like I'll be ordering a new cap & rotor arm in the meantime.

1.1 mm is the gap the plugs are set too from the manufacturer, I guess thats why the part nos end in 1.1

Thanks again for everyone's help.

[manners]

The MAF, 02 or crank position sensor can all affect the mixture as if they are faulty they send wrong info to the ECU. I think the firing order is from the front drivers side 1,3,5 and 2,4,6 on the passenger side but I'm not 100% sure on that.

[cheffy34]

Wouldn't start if it were crank sensor i thought or am i wrong manners i took my maf off and cleaned it with carb cleaner it helped smooth up the running


Dar

[BongoNog]

While I'm waiting for the new bits, I'll have a go at cleaning up the rest of the engine & electrics and check all the filters. A bit of TLC might make all the difference. I'll let you know how I get on.

[dandywarhol]

Well, I took the cap off (after working out how to bend my arm enough to undo the blind screw on the bottom ) and it was dry inside, however the 2 & 5 contacts have completely eroded away. I also found that the cable configuration as inherited from the garage did not match up to the cap numbers , possibly the cause of the wrecked contacts? Give that the fuel mixture is also too rich based on the plugs, I'm not surprised at the performance

Can anyone point me in the direction of where to adjust the fuel-air mix? and which order the cables should be on the engine block? Looks like I'll be ordering a new cap & rotor arm in the meantime.

1.1 mm is the gap the plugs are set too from the manufacturer, I guess thats why the part nos end in 1.1

Thanks again for everyone's help.

Before you start messing about with the air/fuel mixture you'd be best to sort out the distributer cap - if it isn't sparking properly it'll make the plugs wet and seem rich................................

25 thou was the norm for contact breaker setups 30 years ago franco - plug voltages are around 3 times that nowadays - 25/30,000 volts not unusual, so a large gap can be used to help burn all the gas

[apole]

Hi there,

Stick with fixing the HT side of things first.

I've had a blip on mine recently and I'm looking into the Disty cap, rotor arm, king lead and maybe the coil. All of that from Mazda is £129 inc delivery and VAT, disty cap is £43, rotor arm £9 but these things can be inspected first. I don't think an individual HT lead failure will lead to such power loss. The disty cap does have numbers on it by each connection. If you go for a new disty cap don't forget the O ring to prevent water ingress.

Spark plug gaps are 0.9mm from memory on the denso plugs.

You can do a rough test on the lambda sensor, google it and you will find plenty of sites but that is not the primary cause of your problems.

Andy