Re:Engine surge

Hi my jimny is a year 2000 G13BB
Driving at a steady speed the engine surges,has anyone run into that problem and found a way to fix it
Thanks Neil

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Thanks for the reply Lambert, over a period of time I've had injectors cleaned, i run 98 octane fuel, replaced fuel pump and filter, fuel pressure is around 35/36 PSI and when blip throttle 40 PSI
Got me scratching my head

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There are a few things that can cause this but most are related to a sudden change in the fuel/air mixture, so check for:

Vacuum leaks;
Injectors (which you have already checked);
Exhaust Gas value stuck open (if your Jimny has one);
Head gasket;
Fuel (probably not, but where do you get your 98 octane from?)
Have you tried different fuel?
Fuel pump (but that looks normal);
Blocked air filter;
Blocked exhaust
Ignition or a coil breaking down.

What is your fuel economy like?
Is there any smoke coming out of the exhaust, other than normal haze?
Does it smell of petrol at the exhaust?
Does the engine run hot?

Hope that helps.

Hi,
I was thinking fuel delivery, but then you have already looked at that.

So what do we have that will influence the mixture - Lambda sensor?
Same question but timing - Crankshaft sensor?

No experience of this problem, so just throwing out some suggestions.......

A bit of a update,to attempt sort out the engine surge i went to change cam position sensor, i found i could get cheaper non genuine one, big mistake when it warmed up it miss fire at about 4000rpm
Put genuine one so much better
Idles better smoother not surging like before but confused didn't think it was a symptom of failing cam sensor?

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