Surging

[ab56452001]

Hi all , had my xj 4.0 auto for a while with no probs , I love it !. Lately when its been real cold in the morning it starts first go every time , but , after say 30 seconds it starts chugging,surging , chugging for about a minute then slowly clears , like in the old days if you left the choke on!. Im losing no water , theres no dash warning lights and after this episode it runs great all day , and starts fine every time . Was wondering perhaps faulty o2 sensor , maybe fuel pump relay playing up when cold , anybody able to put a finger on it ? , cheers.

[Billnick]

You might have us stumped on this one. What year is your XJ? This will give us a starting point.

[rang0]

Have you changed your fuel filter latley?

Sent from my SM-J100Y using Aussie Jeep Offroad mobile app

[ab56452001]

Originally Posted by Billnick

You might have us stumped on this one. What year is your XJ? This will give us a starting point.

Thanks for reply , it was built end 96 sold early 97 . Ive checked plugs -all ok , replaced fuel filter- old one had almost black gunk inside ! pushed in Shraeder valve while running -heaps of juice , sprayed inside TB , Scanned with tool -no error codes. Next up test TPS and disconnect O2 and check for spark continuity , any other ideas ? , cheers.

[rang0]

When you say the fuel filter are you talking about at the base of the pump assembly? Have you cleaned your fuel rail?

Sent from my SM-J100Y using Aussie Jeep Offroad mobile app

[LuluBelle]

O2 sensor start idle fine cough cough broom broom good that's e what mine was like

[ab56452001]

Originally Posted by rang0

When you say the fuel filter are you talking about at the base of the pump assembly? Have you cleaned your fuel rail?

Sent from my SM-J100Y using Aussie Jeep Offroad mobile app

The inline filter I replaced , the one near the axle , cheers