1991 Jaguar XJ6 engine backfiring

Tiny
CBACON67GS
  • MEMBER
  • 1991 JAGUAR XJ6
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 90,000 MILES
Just got a 91 xj6 from a friend and it backfires and seems to want to die when applying fast throttle. Also seems weak when going up hills. Is this a mass air flow problem or an ignition problem?
Do you
have the same problem?
Yes
No
Friday, August 8th, 2008 AT 12:50 AM

2 Replies

Tiny
AIRSOFTSOLDRECN9
  • MEMBER
Ultimatly it is an ignition problem. The MAF is one of the sensors feeding information to the ECU about the incoming air/fuel mixture. The best way to test this without using a pre-obd type tester for the ECU is to unplug each component of the following, one at a time. TPS, MAP or BMAP, MAF, 02 and EGR. Most likely the TPS or MAF would be the issue under higher throttle.
Was this
answer
helpful?
Yes
No
Friday, August 8th, 2008 AT 1:21 AM
Tiny
JAMES W.
  • MEMBER
Backfiring is a very broad term. Backfiring usually occurs out the tail pipe and is by a malfunction of the ignition system or engine timing. This would point to the plug wires, carbon tracking in the distributor cap or a problem with the crankshaft position sensor or ECU.
The other condition often called "backfiring" is "lean coughing" which usually shows up as poping back into the intake system or air cleaner, sometimes showing up as black residue in the air flow meter and intake duct work. If this is the case, and by your description, I would say your engine is running lean. The first I would is change the fuel filter. If you have already done this then, as mentioned above, it could be one of your sensors or the ECM. Any of these should show up as a trouble code and a check engine light.
Was this
answer
helpful?
Yes
No
Sunday, September 28th, 2008 AT 3:30 PM

Please login or register to post a reply.

Recommended Guides