Jeep HEMI with lpg gremlins.

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Speedtorque
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Jeep HEMI with lpg gremlins.

Post by Speedtorque »

Hi, I have owned my Jeep for a few months now,It has a Stargas system with twin regulators. I got it serviced after I bought it (none of the filters were considered worth changing as they all flowed well). It has a spare wheel type tank of about 75l.

The trouble is I have had glitches from day 1, but only beginning to understand them now.

With a freshly filled tank, or one that's nearly empty. If I "floor it" sometimes it will reward me with lots of power and other times it looses all power after about 2 seconds of WOT. the system is still running in gas, no warning lights pop up. Power is restored if you close the throttle and reapply it gently.

Is that a gas problem or is that "limp mode" from the ECU?

BTW it never does this when switched to petrol.

Also, the gas level lights are all over the place, even when cruising, it makes a audible tick when it goes to the red light, but the installer insisted that this in not switching back to petrol, he couldn't explain the noise.

More receintly, I have noticed problems with it actually switching to petrol (all gas indicator lights flashing) even with a full tank. This sometimes allows me to switch it back, but on occasion I have not been able to until restarting the engine.

I'm sorry to bombard with all these problem, but I wonder it they are related?

Cheers

- John


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ChrisJC
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Post by ChrisJC »

Hmm. Weirdness is often an earthing issue. Do you know how the fuel sender is earthed. And how the tank solenoid is earthed? They should NOT be earthed via the tank itself as that should be insulated from the vehicle body.

Chris.
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Speedtorque
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Post by Speedtorque »

I never thought of earthing...

I'm guessing the fuel sender would be a pressure sensor in the regulator? both of these have a socket with 4 pins one has a plug in it.

As for the tank solenoid, I'm not sure where that is, but I would presume close to the tank, so I'll have a peep at some point.

Can I assume that the varying gauge is not normal? I have an old Cherokee with LPG and the lights are rock steady in that. (Prinz system)

I'll give the installer CG Gas Peterborough a call tomorrow to get the location of the items, then Ill have a peep.

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ChrisJC
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Post by ChrisJC »

The gauge sender is on the tank, as is the solenoid. It is a float system, just like a petrol tank. (well, similar, but the float is inside the pressurised tank, the sender is outside, separated by a brass plug).

Chris.
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Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8

Speedtorque
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Post by Speedtorque »

I had a look underneath and found the tank was not isolated from the car body. Is that ok? The solenoid was connected with a good waterproof connector. However the sender had 3 wires and connected with a cheap 4 pin plug, most of the pins were green. I cleaned it up and found the fuel gauge lights to be much more stable and have not had switch over problems since. I hope this is the end of that problem!

Many thanks!

John
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Post by ChrisJC »

I think isolating the tank from the car body is a safety thing - so no electrical currents can flow in the tank and cause a spark.

Yet some tanks (e.g. my doughnut tank) is definitely not isolated, but the torpedo tanks on my Landie are....

Maybe not so important.

But most certainly none of the electrical components on the tank (sender & solenoid) are earthed via the tank.

Chris.
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Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8

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