Bucking when driving

BangkokDean

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Mar 25, 2008
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Bangkok
Hi, My L98 motor all of a sudden has started bucking or pausing when driving. It idles OK cold or hot 183*. I set the TPS to .54 volts using two paper clips + to the center wire and the – to the top wire.

The fuel pressure with key on is 30lbs and after 30 minutes key off it drops to 16lbs.

When running the fuel gauge bounces all over the place 10 to 50 very fast.

The Trans is a 700R4 I drive in drive and overdrive with the same surging.

Please let me know what you all think the problem is, thanks
 

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The fuel gauge is all over the place when running. is the natural?


https://www.facebook.com/dean.giliard.3/videos/274635523019744/

FB comes up with N/A on your link.....

yup 42 something is fine at idle, anything lower is suspect, pull the vac line to the regulator and look for gas....much lower pressure and you in trouble....check that the pump is getting a full voltage basically same as alt is putting out....if it does and you ain't got pressure, I have to say either bad fuel filter or pump....
 
Fixed, changes the in tank fuel pump and the fuel filter, now 43 lbs fuel pressure. runs like it should.

The only new problem is when at running temps it is difficult to start. Takes several tries to start?
 
Last edited:
Fixed, changes the in tank fuel pump and the fuel filter, now 43 lbs fuel pressure. runs like it should.

The only new problem is when at running temps it is difficult to start. Takes several tries to start?

vacuum leak

Finally fixed the problem. The in tank fuel pump had a leak in the fuel line in the tank itself. Now it holds 45 lbs pressure and actually starts right away and runs better than it had in the past.

Finally...:drink:
 
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