Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: prozac on October 23, 2006, 10:27:53 AM

Title: Won't start easily
Post by: prozac on October 23, 2006, 10:27:53 AM
Hi all!
4.0 XJ has been excellent for the last 8 months ....

until I left BT Derby this morning at 01:00, when she decided not to start easily. Running like a bag'o'shit. Sounds like it's gasping and farting and running on 2 cylinders.

I checked the engine bay but could see nothing obvious.
After about 5 mins it did eventually fire up and ran home with no problems.

Gone out this morning and the same again.

It needs a service, it probably needs a BIG service.

I keep thinking TPS, though not sure why.

Any suggestions?
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Post by: Anonymous on October 23, 2006, 10:29:09 AM
Crank position sensor?
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Post by: prozac on October 23, 2006, 10:57:09 AM
booked it in for a service but now can't start the bastard.
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Post by: Mike Pavelin on October 23, 2006, 12:16:10 PM
Before you try to start it next time, find the fuel pressure test port on the fuel injector rail, it's a big schraeder valve like on a tyre. press in the middle (wear a glove) and see if you get fuel squirt out at high pressure. If not or if it just dribbles out, you could have a problem with the fuel pump leaking internally or an injector leaking and losing the rail pressure when parked. If so, try turning the ignition on and off a couple of times before cranking and see if it starts up normally.
If it then starts and runs ok, this is the first place to look.
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Post by: prozac on October 23, 2006, 08:58:30 PM
Cheers Mike!!
I take it fuel under pressure, squirting out the schraeder valve is good?

The garage have taken it away after the mechanic looked at it on my drive.
He seemed to think there was too much air, it did sound really asthmatic and 'sucky'  :? It wouldn't start properly, it was just wheezing and almost like a soft backfire, without the bang. Can't really explain it better than that.

I'll keep you informed.

Martin
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Post by: greggmo on October 23, 2006, 10:26:04 PM
it almost sounds like something breathing where it shouldnt be.
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Post by: prozac on October 25, 2006, 09:23:54 AM
I'll contact the garage today to see what the prognosis is. But think ing about it this morning....... never a good idea........ when I left BT Derby, I'd not been there long so the engine was warm/hot and the LPG system was more likely to work..... I flicked it onto LPG but I can't remember when, it could have been before leaving site, and it drove home perfectly on LPG..... which would maybe point to the fuel system as Mike suggested, maybe it's "not enough fuel:air" ratio rather than just too much air.

I'll see what the garage think.
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Post by: prozac on October 25, 2006, 09:24:13 AM
I'll contact the garage today to see what the prognosis is. But think ing about it this morning....... never a good idea........ when I left BT Derby, I'd not been there long so the engine was warm/hot and the LPG system was more likely to work..... I flicked it onto LPG but I can't remember when, it could have been before leaving site, and it drove home perfectly on LPG..... which would maybe point to the fuel system as Mike suggested, maybe it's "not enough fuel:air" ratio rather than just too much air.

I'll see what the garage think.
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Post by: keeko on October 25, 2006, 08:29:28 PM
Mike Pavelin....................the knowledge daddy. :)
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Post by: MK1 on October 25, 2006, 09:49:18 PM
Quote from: "keeko"
Mike Pavelin....................the knowledge daddy. :)


That's Doctor Mike to mere mortals of the Jeep world like us!
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Post by: Bubba on October 26, 2006, 10:05:10 PM
just to fly in the face of reason i am gonna go for cam sensor
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Post by: prozac on October 26, 2006, 11:13:13 PM
Quote from: "V8 Bubba"
just to fly in the face of reason i am gonna go for cam sensor


Sounds plausible. Are these major jobs?
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Post by: MK1 on October 27, 2006, 10:37:00 AM
Quote from: "V8 Bubba"
just to fly in the face of reason i am gonna go for cam sensor


You'd say black was white just to cause trouble you would.  :wink:
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Post by: Bubba on October 27, 2006, 11:42:29 AM
no tis just that the cam sensor can almost mimic other problems like other things in life that tells you one thing but means another
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Post by: prozac on October 27, 2006, 01:30:12 PM
Garage thinks there is no fuel pressure. It had a gas conversion done from new by Exeter Jeep. They've replaced the original petrol tank woth a smaller petrol tank and put the gas tank underneath. It's a lovely job. I'm hoping Jeep used the original Jeep fuel pump. Assuming it's the fuel pump. Oer is it likely to be something else. Some fuel gets through, as the car will start and run, badly, but it runs-ish so obviously something is getting through, it's when you press the accelerator it gets worse.

Any suggestions.?

Cheers
Martin
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Post by: chrisjones on October 27, 2006, 01:36:29 PM
It's not something daft like a blocked fuel tank breather is it??

Does it suck air into the tank when you take the cap off?
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Post by: Mike Pavelin on October 30, 2006, 07:03:34 AM
Hook up a pressure gauge to the port on the fuel rail, if you have a stable pressure of about 48psi regardless of throttle position when running. If it's considerably lower the fuel system is at fault.
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Post by: prozac on October 30, 2006, 07:34:27 PM
Garage believe it to be the fuel pump.

We shall see
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Post by: prozac on November 03, 2006, 04:53:22 PM
Was indeed the fuel pump, made all the trickier by the LPG tank and Towbar :oops: ) Would Lighthouse be likely to stock them? or Jeep for that matter.

Car seems to be running fine now  :cry: