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[Shaunfella]

Hi folks...been a while since I've had any issues to post and ask for the forums invaluable help!

Got a 2006 TJ 4.0L sport.
 
The problem was that the car was very slow and had no pick up. It's usually fairly nippy off the mark but now just dies when I put my foot to the floor. There is a sort if low dull noise that sounds like air intake or something but it definitely does not sound right. I struggle to get 100 kph out if the cat whereas before it could sit at 140 no problem. When I put my foot down the revs go up but the speed doesn't

The engine light and code indicated that the O2 sensors were gone so had them replaced thinking that may have been the problem but no luck.

As u can tell I'm completely useless when it comes to under the bonnet stuff so would.apprwciate any suggestions for stuff to check before getting my pants pulled down at a garage. Spark plugs and O2 sensors cost me 350 and after checking online I think this was expensive.

Any help much appreciated!!

[JamesH]

You could check the fuel pressure, if the pump is failing it won't delivery enough fuel and can trigger error codes from the O2 sensors because the fuel air mix ends up wrong. There is a test valve on the fuel rail.

[Mike Pavelin]

I would check for a blockage in the cat / exhaust system.

[Ezz]

"The revs go up but the speed doesn't"

Clutch slipping..

[Shaunfella]

Thanks for the suggestions guys!

[Shaunfella]

Could it be the TPS?  Seen some stuff online that describes similar symptoms....

[bgbazz]

"The revs go up but the speed doesn't"

Clutch slipping..

I'm sort of wondering the same...any strange smells when this happens?

[Shaunfella]

"The revs go up but the speed doesn't"

Clutch slipping..

I'm sort of wondering the same...any strange smells when this happens?

Nothing out if the ordinary. Like I said ..The only noticable difference is the power/speed and the low pitch noise its giving out...really frustrating.

[bgbazz]

That's fair enough...the fact that the revs go up, but the speed doesn't, points to something slipping.

[Shaunfella]

That's fair enough...the fact that the revs go up, but the speed doesn't, points to something slipping.

It does accelerate but it's no were near as powerful as it was before the problem developed. The car would wheel spin no problem from a standing start....now it wouldn't pull skin off cold custard......

[Shaunfella]

Just out in the car again.....Top speed was 100 kph and the car wouldn't go above that or 3000 rpm....very very sluggish and sounds like it has a sore throat

[wildwood]

blocked cat or exhaust box......

Had this on a TJ after a mullaring  in the mud at Tong

Bits of aero bar cat had come loose and were blocking proceedings

[Shaunfella]

blocked cat or exhaust box......

Had this on a TJ after a mullaring  in the mud at Tong

Bits of aero bar cat had come loose and were blocking proceedings

You sound certain...that's good enough for me...take it that's why my O2 sensors were flagging up as gubbed then....

[wildwood]

District lack of power on road to beer purchase ......but had been OK on road to Tong....

Rattle cat was part of Prob but after taking exhaust box off...... Easy as was side exit shorty at the time .....we found it had taken a smack and although not visible from outside ....looking in to box the outlet was less than half the size.......

Driver ended up going home on cat and open pipe

Black TJ now owned by Cockney Boy.......but then multiple abuse sessions from the appropriately named 'Coyote Ugly' Chris........
Oh happy days indeed........ How we laughed at his demolition skills

[JamesH]

I had same symptoms, gutted the cat and got no change in the problem. Turned out to be a fuel pump only capable of delivering 20psi when the engine needs 49psi.

[Shaunfella]

I had same symptoms, gutted the cat and got no change in the problem. Turned out to be a fuel pump only capable of delivering 20psi when the engine needs 49psi.

Anyway to check the fuel pump without putting it into a garage??

And when I say check....I mean an easy method for the mechanically dumb....

[Dave69]

screw a pressure gauge onto the fuel rail, should be a standard shraeder fitting (push bike inner tube type)

[Yakko]

I'm confused. Are the revs going up without the speed increasing?

If so, surely it can only be clutch?

[Shaunfella]

I'm confused. Are the revs going up without the speed increasing?

If so, surely it can only be clutch?

They're going up and the speed is too but it's got nowhere near the grunt it should have. Then once it gets to 100kph and 3000 rpm it won't go any further.  Usually it can sit at 130-140 comfortably.

[JamesH]

Fuel pressure test gauge screwed into test valve. Test gauge kit is about £40.

[Shaunfella]

It's going into garage tomorrow so fingers crossed it's nothing to painful (wallet wise).. hoping I can point him to the fuel pump  exhaust/ cat blockage and that's what it be!!

[Brachunky]

I'm confused. Are the revs going up without the speed increasing?

If so, surely it can only be clutch?

Put the tj's handbrake on firmly & try pull away in 2nd & see if the revs rise without moving forward

[Dave69]

Not teaching people to suck eggs but identifying a slipping clutch is quite evident.

drive at 30 in top gear and then accelerate hard, car wont speed up that quick but the revs will raise quickly.

don't recommend the hand brake and drive away.

[bgbazz]

    ...with Dave. A slipping clutch will only be evident in top gear and low speed, just as he said. If it happens at low speed, in a low gear, it's totally knackered!

[Shaunfella]

It's an automatic I have........