Print

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

[Green Jeep]

Hi,

Starts, runs and drives perfectly from cold, if you switch off and start again whilst the engine is warm then after 20/30 seconds the engine sucks air, lumpy idle, doesn't stall but almost sounds like it will and that it's not running on all six, backfire noise when under load, then will clear itself and run perfect after a minute or two.

I have cleaned the IAC and throttle body, put injector cleaner in the fuel tank, checked all the vac pipes, connections to sensors.

No DTC's, fuel pressure in the rail seems fine.

Any idea's, thanks in advance

Maf

[LairdScooby]

Hi Maf,

souds suspiciously like you have an air leak on the manifold. When it's running rough, try spraying WD40 or similar slowly down the length of the inlet manifold - you'll notice the engine note change if/when you find the air leak.
The reason it doesn't happen when it's cold is the ECM richens the mixture for cold start hence overcoming the air leak.

Also worth checking all the rubber hoses that attach to the inlet manifold to make sure they're not split, loose, broken etc. Also as a possibility, your brake servo could have an air leak which would let air straight into the inlet manifold. Had this on my 95 Rover 827 Sterling and changing the servo was the only answer. Same symptoms as you describe as well.

[Green Jeep]

Hi,

Thanks, will try that, cheers Maf

[Bishops Finger]

Its probably got a smashed rear light like the GC you sold me but forgot to mention

[Green Jeep]

Its probably got a smashed rear light like the GC you sold me but forgot to mention

Really unsure of your definition of smashed and why two years after buying a Jeep with low miles at trade price you continue through socia media to bleat on about it, instead of contacting myself directly....

Don't look very smashed to me?

[LairdScooby]

Hi,

Starts, runs and drives perfectly from cold, if you switch off and start again whilst the engine is warm then after 20/30 seconds the engine sucks air, lumpy idle, doesn't stall but almost sounds like it will and that it's not running on all six, backfire noise when under load, then will clear itself and run perfect after a minute or two.

I have cleaned the IAC and throttle body, put injector cleaner in the fuel tank, checked all the vac pipes, connections to sensors.

No DTC's, fuel pressure in the rail seems fine.

Any idea's, thanks in advance

Maf

Did you get to the bottom of this problem Maf? Also does it have LPG? I had the same on mine recently with a high CO reading (0.8% on petrol, 3.8% on gas) due to a bad earth on the engine block (right hand rear, near the oil filter/starter motor area) which is where the Lambda sensor picks its earth up from. Loosened, wiggled (to clean it) the connectors, tightened it up and job done. Might be worth looking at even if yours doesn't have LPG.

[Green Jeep]

Hi,

Yes it has LPG, which isn't working at the moment.... was at the lpg specialist on Friday... tries to switch over, fails and back to petrol...

I found that disconnecting the temp sensor (themostat one) makes it run better, most times perfectly... so will replace that and go on with it

Will check that earth connection, thanks for the idea, maybe linked to the lpg problem, would be a nice fix... cheers Maf

[Green Jeep]

Think I've finally got to the bottom of this one....

Ignition coil was getting too hot and breaking down under load...

Competed at the weekend and had to poor water from a stream over the coil, pulled the coolant sensor wires off so the second fan was constantly on and left the bonnet up on the catch, all of which meant we managed to complete the event and bag another first 

[JamesH]

Try a vent on the bonnet to help let the heat out

[Green Jeep]

Try a vent on the bonnet to help let the heat out

Should be okay now, old coil had cracks all over it...

[LairdScooby]

Brings a new meaning to "cracking up" really! Let's hope it solves the problem although i don't see how it could cause the wheezing/sucking noise.

Have to confess, if the coil ever goes on mine i think i'll be relocating it somewhere high on the bulkhead/inner wing sort of area and changing it for a standard type so i can use a standard king lead.

[Dutch]

Brings a new meaning to "cracking up" really! Let's hope it solves the problem although i don't see how it could cause the wheezing/sucking noise.

Dunno if you have ever seen Maf compete in a punch hunt 

From ripping XJ PCM's out and waiving them around in the air to cool down to his winch bitch sitting on the bonnet of his TJ in a 'sticky section' and then blowing the top of his radiator.  That was 'kin funny actually, could that chap move or what !! 

[LairdScooby]

Easiest way for me to answer that is...............

.................what's a punch hunt?

Also what is a "Winch Bitch"? I can make a guess on this but no clue on punch hunt so an answer for both would be good please!

[Brynjaminjones]

Brings a new meaning to "cracking up" really! Let's hope it solves the problem although i don't see how it could cause the wheezing/sucking noise.

...to his winch bitch sitting on the bonnet of his TJ in a 'sticky section' and then blowing the top of his radiator.  That was 'kin funny actually, could that chap move or what !! 

Heh heh, that was very amusing!

[Green Jeep]

Punch hunt is like orienteering with vehicle, you have a card attached to your truck with A1-10, B1-10 etc or just numbers and colours...

... you then have to get your truck to the punch (which is like a stapler with a unique pattern) to show that you got to that punch.... when you have completed the card you can get another fitted on to the drivers side and that makes some punches easier and some harder, good for the memory as well.

Really good time can be had and imho makes pay and play days boring and pointless, with the punch hunt you have an objective and acheivement to get.... all for a crappy plastic trophy... got a few now... 

[LairdScooby]

Thanks for that detailed explanation - basically a treasure hunt with a few twists involved then?

As for "Winch Bitch", i'm guessing co-pilot/passenger/navigator/ballast to sit on the axle slipping the most, (previously) good friend or similar?

[Green Jeep]

Winch bitch is the crew man, who works really hard, gets covered in mud, has wet feet and doesn't spend much time in the truck... worth their weight in gold when you get a good reliable one and you work well together, doesn't matter how good you or your truck is, the crew man/women makes all the difference...

[LairdScooby]

Thanks for that - bit more involved than i thought but i was along the right lines.  I'll have to fully evaluate my truck before going on something like that, i know there was a problem with the transfer case some time before i bought it (belts went so i'm told) and i'm not convinced everything was put back correctly - i can get it in to 4wd no problem but getting it back to 2wd can be a struggle!
It also feels like it's "winding up" on the back axle in 4wd, don't know if it's just me not being used to it or whether some clever article has changed a diff and got the wrong ratio - at a guess if someone got the wrong ratio that could potentially cause the belts in the transfer box to go.

[Mike Pavelin]

Belts?

[LairdScooby]

Belts?

That's what i was told, belts. It didn't ring true to me either a bit like he'd just had the steering fault repaired - yeah, right! The steering box was hanging on with overlength M10 bolts with a couple of random nuts on the end there were holes in the chassis rail where the box was meant to bolt on and i could turn the steering wheel half a turn in either direction before the roadwheels budged a degree.

So the bottom line is i'm guessing it should have chains instead of belts in the transfer case if the transmission isn't done with gears from front to back or should that be back to front. I've had a very quick squizz at the Haynes Book of Fantasy but haven't really looked properly at the transfer case at all. I will when it comes back from the MoT station where it's just recieved another years life support ticket...........and a new sill.

The other reason belts didn't ring true was because the transfer case is full of ATF (or should be) and that will cause belts to slip. It might even be low on fluid or have the wrong fluid in, i just don't know. I bought it back in the summer with the intention of doing all the MoT prep work before the test and then using it over winter. However, the best laid plans of mice, men and Scooby went completely and utterly pear-shaped. All i got done was the steering box and reinforcement plates, some wiring problems and an assortment of lighting, braking and general service items to get it to MoT standard. That said i also managed to get a friends Saxo moT-ready (apart from a Billy Bull fail on headlamp aim and emissions, both of which were fine), sort out a few faults on another friends Rover 827SLi (was mine before i sold it to get the Jeep) and sort some overdue faults on my Rover 827 coupé.

So...............................when i get my Jeep back next week (when one or other of the aforementioned friends can take me to the test station to collect it), it will be gettting fresh antifreeze, some new interior bulbs in the roof console, new speakers in the roof and the gear selector linkages (both transfer case and gearbox) checked/adjusted and possibly fluid changes on both.