Initial Acceleration Misfire

Luke

Hi all,

I've got a misfire in my '79 244gl under initial acceleration. The car cruises smoothly and the miss disappears above 2000 rpm (or thereabouts) when accelerating. It does sound like the fuel pump is running pretty loudly when ignition is on.

Just had it serviced and the miss is still there. The mechanic said compression in all cylinders is fine, fuel mixture was adjusted.

He suggested it could be an injector or the distributor pump? He didn't have the gear to check mechanical injection.

Before I find a local injector specialist to fiddle around with it, does that seem like the culprit? I did a bit of reading on the various forums (before the service) and the symptoms sound like maybe the in-tank fuel pump has carked it?

I've got limited mechanical knowledge/skills to check stuff at home.

Thanks,

VolvoDeger

what area are you in as one of the techs here might able to drive and advise you...

VolvoHordz

Yeah a loud main fuel pump can be a symptom of a dodgy intank pump. Pretty simple to diagnose with a just a length of wire to jumper between fuses. You should be able to find guides on how to do it online easily enough.

Is it dependent on the amount of fuel in the tank? The main fuel pump has to work harder when the fuel level is low and the intank is not working.

VolvoDeger

If it was in to see me I would be going straight to the dissy cap and rotor first...fuel distributor i doubt very much.

Luke

VolvoDeger;125723 wrotewhat area are you in as one of the techs here might able to drive and advise you...

I'm in West Gippsland (Trafalgar), Victoria.

VolvoHordz, I'll check to see if I can find a good guide to check the intank pump and post back.

Much appreciated

VolvoDeger

79 240 going back now and testing my memory,,fuel pump should be beside the tank so just remove carpet and cover in boot then power pump that way. Check and see if getting power when cranking to plug, but once again I doubt if pump your issue.

Luke

Just to close out, I traced the issue to a corroded fuel pump relay and connection to fuse 3. Just got the replacement relay and all seems good. Thanks all for your help.