Sputtering after road bump

[Alwin]

My 98 6.5 runs perfect until hitting a bump in the road ... about a kilometre later it sputters a bit and sometimes revs up a bit .... followed by running perfectly.... any help where to look is much appreciated !

[a5150nut]

Welcome to TDP

My guess would be somewhere in your fuel line between the tank and lift pump you have a slight air leak. When hitting a bump it jars it just enough to let in a tiny bit of ar and the injection pump is able to overcome that small amount.

Just a guess mind you. But a place to start looking.

[2INSANE]

Could be a loose wire or connector? I’ve had a starter wire hit the frame every time I hit a bump and it made the truck sputter.

[Robyn]

Both the above are possible.

I tend to go with the air leak.

Connect some clear plastic tube in the fuel return line to the tank.

Connection is at the rear of the engine.
Run a loop up by the wipers so you can watch it.

Possibly need to leave the hood on the safety hook to allow the hose room to fit.

The fuel return line should have a constant flow going back to the tank.
After hitting the bump/a bump ...watch for a stream of bubbles.

There are only a couple places that have flexible/rubber connections between the fuel tank and the lift pump'

There is one other place that can be an issue....IN THE TANK AT THE SOCK BYPASS VALVE.

Does this anomaly happen when the fuel level is low ...like 1/4 tank or less or does it matter ????
If the issue is at low tank volume....then I would suspect the bypass valve may be bad and allowing air to suck in during the "Sloshing of the fuel " during the bump.

Give things a whirl and see wassssssup.

Good luck.

[Alwin]

Could be a loose wire or connector? I’ve had a starter wire hit the frame every time I hit a bump and it made the truck sputter.

thank you so much for your response.... much appreciated!

[Alwin]

Thanks for your response Robyn ... when I find the problem I will follow up here . Thanks again !

[Robyn]

You betcha.

Keep us in the loop.

Good luck