surging

[vibefpv]

hi guys can anyone help we have a 92 laser when idling its fine when driving along in drive the car will sometimes revs fro 2000 to 4500 canany one help with the probs ,
cheers jim

[graham7773]

Manual, I guess? I would be looking at all of the air intake system for split hoses and loose clamps. Is the air cleaner element good? Next I would inspect every vacuum line including the one going to the brake booster. listen to the brake booster. It may have some hissing going on. That indicates a leaking diphragm...not good. On the smaller vac lines look for hardened and split or loose hoses and replace them. Not expensive. Yours is a carby model? Water in fuel can be a problem as well. If you are running E10, that reduces the risk posed by water contamination. But I personally would not run E10 all the time. Ford recommends that Telstars around the 1993-4 should not use E10 due to problems it causes in the Telstar fuel system. I don't think that applies to Lasers.