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MAF sensor?

jdxj

NAXJA Forum User
Location
Colorado Springs
So I bought a non running 2000 XJ sport 4.0 yada yada tottally stock.
previous owner replaced the MAP, TPS, Coil rail, Injectors,Computer,Cam sensor,
Still wouldn't run so I got it for a steal. I've replace the coil again, Idle control motor, swaped the original computer back in, and the Crank sensor,

after the crank sensor it starts but still runs like crap.

It starts and runs great for about 30 seconds then it start to idle rough and if you try and drive it it just falls on its face spitting and sputtering, I'm kinda lost.
I have a good running 01 sitting out in the driveway too so i can swap parts back and forth at no $cost just time but honestly i dont know where to go from here.

Everytime i hook it up to the scanner it gives me a different code,
Ive had 1391,0100,0152,0351,0352,o2 sensor code cant remember the number,
and everytime i shut it off and reset the codes it comes up with a different code next start up.
I did check the Vin on the jeep and the vin on the computer do match,
The code its throwing now is p0100 MAF sensor circuit, :twak:I thought jeeps didnt use a MAF?

WTF please help


ANY IDEAS
 
Fix the P1391 first. The rest of the codes may clear up. After fixing the P13191, fix the rest in numerical order, lowest numbered codes fix first.





P1391 Intermittent Loss of CMP or CKP. Loss of the Cam Position Sensor or Crank Position sensor has occurred.

P1391 – Possible symptoms:
(1) random misfire/stumble/stalling, usually over bumps or right turns and reverse.
(2) shorted out the Fuel pump/ecu constant power wire and every time I'd go over a bump it would pop the fuel pump fuse and kill the motor.
Partial Fix:

Cleaned/replaced engine GROUNDS! - Found braided ground strap from valve cover to firewall touching metal brake line on firewall and "shorting out" !!!

-Rerouted ground strap away from brake line

Real Fix #1:

Found an engine wiring bundle at firewall was wrapped around the backside of the fuel-rail. The fuel rail had punched through the corrugated plastic wire and
black tape covering also worn through... dug deeper... "3" three wires in that bundle, right at the same spot, had the insulation worn through just enough to barely expose the wire. It all made perfect sense... every bump or right turn was enough to touch these wires to the fuel rail causing a short i.e. intermittent loss...!!!

-Wrapped the wires individually with tape, wrapped the bundle with tape, replaced plastic protector and wrapped with tape... Pulled the bundle up and away from fuel rail secured to the other wire bundles on the firewall.

Real Fix #2:

Timing is off. Re-index distributor per the FSM instructions, or replace faulty distributor.

Google Scan Tools, O-Scopes and Toothpicks, read the article.

A mis-indexed distributor may exhibit surging, light bucking or intermittent engine misfiring. This will most likely occur when the vehicle is at operating temperature and under a light load at approximately 2,000 rpm. This condition may be caused by a mis-indexed distributor.
The factory procedure must be used as outlined in the service manual. Some of these may be indexed with a scan tool, while others require the use of a volt meter to verify position.
 
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