Outer Limits 4x4 Board

Hi guys,

I have my Feroza running on both fuel and LPG. Since i bought this car, during a year i usually used LPG (cheaper, more eco-frieldly..).

Last week i was driving on fuel(!) when roza started to shake and suddenly died. Looked for me that a fuel pump could broke as I tried to start it again..and again..and nothing. Fortunately, i had couple litres of LPG left and could use that to start the engine (worked!) and continue the trip. Yesterday, i got my mechanic to check it and it seems that fuel pump is ok but he said that this looks like injectors are fully chocked!

I know that injectors can sometimes need to be cleared but as i heard it was rather related to power loss symptones. In my case, I didn't had such problems, my car died almost suddenly! Is it possible that injectors can be so dirty that the car will not go and even start!? I tried a clutch-start while going down from the hill couple of times but no result too.

I am wondering if that could be related to driving on LPG instead of fuel almost all the time lately. As i belive, if fuel pump is turned off, injectors are still operating but having no fuel they becoming hot and finally stuffed? burned?

Is it possible that this is caused by injectors? Will the cleaning help? Anybody had the same scenario with injectors stuffed so much?

Thanks a lot!
Lukas

I'm no LPG expert, but I believe in the case of the Feroza engine that your ECU could be completely disabled when LPG is running. The reason being that the ignition timing has nothing to do with the ECU. Whether or not your's is set up like that though?

You're right about the injectors needing fuel for cooling when operating(from what I've heard anyway!) The coils inside them can burn out. If you disconnect the wiring loom from each one they should give a low resistance reading on a multimeter ie. usually 4-10 Ohms IIRC.

Do you think that injectors cleaning could help if the coils inside are burned out?

If the coils are burnt out you'll need new injectors- they won't be repairable. If they're clogged then make sure they are removed to be cleaned, as that's the best way to do them.

I took mine out and had them ultrasonically cleaned and flow tested about 18mths ago, the cost was around $25 per injector. If you take them out yourself you'll save a lot in labour costs. It's reasonalby easy to do, just be careful as the fuel rail is pressurised all the time.

You could also check your fuel pump out by doing a flow test. The Service Manual has got details on how to do it.

I don't run LPG, but was told unless you run half a tank though it every month or so, (or less but more often), the gaskets dry up, injectors clogg, etc, cause LPG doesn't have the cleaners like petrol, and has a very low oil content - also is @#$@# cold going through the injectors then burns, causing hot'n'cold spots......

Though I was on;y 'told' this stuff, and don't run it meself...... I've got a mechanic training handbook somewhere, I'll take a look at the LPG chapter if you want....

Thanks, i would appreciate if you could check that.

LPG is very very popular here in Poland and when the LPG installation is good quality, there shoudn't be any problem with fuel system at all. Mine is very simple, without an LPG injection and computer so potentially could cause long-term problems like these nasty injectors. On other hand, i am lucky cause i was able to start my car on gas when my car stopped. If that would be controlled by LPG Ecu i wouldn't be able to do that as it only allow to switch to LPG when engine is started on fuel and warm enough.

Lukas

Just looked - there is about 30 pages if you are interested, I can scan, but goes into everything from the tank mounting to the pipes - it is a full training book for mechanics.

Though, there is a key paragraph I found, with it's own heading

Periodic operation on petrol

To maintain the petrol fuel injectors ina serviceable condition, vehicles witha dual fuel system shoud be run on petrol for a period each week. it is recomended that about 20 litres of petrol be used over a four-six week period or diring each 3000 km's.




Should cover it, and would by why the injectors are now fubar......