Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[marsie]

As some of you may know i have recently bought a 1999 wj grand cherokee with LPG.Recently it has developed a starting fault :twisted:

[Mike Pavelin]

There s a seal inside the fuel pump which fails, causing the fuel rail pressure to leak back to the tank when the engine is turned off. This causes long cranking times and eventually poor running. The seal can be replaced but the tank has to come out to access the pump.

[Bubba]

ouch if thats what it is

[Mike Pavelin]

Get hold of a fuel pressure gauge that fits onto the test port on the fuel rail. Run it up and then switch off and watch the fuel pressure. After about 5 minutes there should still be around 20 psi in the rail. If not, the fuel pump is suspect unless there is an external fuel leak..

[marsie]

Checked the fuel at the rail.Got loads of pressure when the engine was running but as soon as it stopped just as spray of fuel then nowt.Turn ignition off then on,got a 2 sec buzz from pump and a spray of fuel then nowt
Has been starting fine today,only seems to be when its hot weather(been a bit cooler today here).Plus even when its left over night it always starts first click??? only has problem on really hot days when engine is upto temp and its left for about 10-30mins  :twisted:

[Bubba]

cam sensors act all funny like that if they are going fubar

[jeepey]

my dads 03 4.0L TJ does exactly the same as what you described . dealers reset the computer and still takes a while to fire up when warm  :? seems abit of a mistery

[marsie]

Hmm? think i will let it develop.If it dunt get any worse i can put up with it :twisted:

[wazza]

have you had any trouble or noticed it running hot?

it could be the temp sensor on the thermostat housing,

it'll be thinking its cold an chucking stacks of fuel in.

it happened on my cherry similar but not as bad as you described, all i did was unplug it, so it thought it was running hot,  an it  kicked the lecky fan in perminant  till i got a replacement. had to plug it back in to start on morning cos it was to lean to start otherwise.

[marsie]

On the guage it usually runs halfway,about 100??
Paul

[isle of man]

temp 2 sensor or whatever it's called the one that sends to the pcm, on the front of the engine.





peter henry

[Mick O]

Sounds a bit like what I had on my XJ.

Stealer had it for 3 days

[marsie]

Where is the cam sensor located,how much £££s and what are they like to fit? May fit one if they arent too dear and see what happens.Been running really sluggish today,no missfires or owt just seemed down on power?
Paul

[Mike Pavelin]

If it's a 4.0 it's where the distributor used to go on the r/h side of the engine block near the oil filter, if it's a 4.7 it's on the underside of the r/h cylinder head. I'd still fit a pressure gauge to the fuel rail and check it properly though.

[marsie]

Cheers Mike,dont think its fuel presure cos its the same when running on LPG,Tried switching today between LPG and petrol but it was sluggish on both :?
Paul