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Common problems with Landi Renzo

Diagnostics & Troubleshooting

Irregular idle, misfiring at idle or during acceleration, codes for System Too Lean or System Too Rich may indicate a problem with your injectors. If you are having the same problems on petrol, the problem is most likely somewhere else and not in the LPG/CNG installation.

Other problems, such as the system not switching to gas (beeping or just engine dying) may be caused by a lot of Landi Renzo components. To be sure what the problem is, you need to diagnose it with the software corresponding to your ECU.

Common problems with reducer is to have too high pressure or leaking gas througout the vacuum line. 

  1. Vacuum line gas leak – a simple check is to turn the engine off, pull the vacuum hose out of the reducer and soap the inlet of the reducer. If it blows a bubble, try again 3 more times. If it blows it 3 more times, then your reducer needs change or repair. Common problems caused by the gas leak from the vacuum line is hard start (too long crank without start) or too rich mixture at idle/driving.
  2. High pressure – to check if the reducer is having a bad pressure flap, connect to the software, switch to GAS and then switch to PETROL. The pressure (absolute or diff) should not reach more than 2,6bar when idling on petrol. Wait at least 10 minutes on petrol to see if it reaches it.
  3. Safety valve leaking – the safety valve can be leaking gas if the pressure is too high or the valve itself is bad. Check for high pressure during gas operation and if it is normal (below 2 bar when on gas), change the safety valve.

This sums up the common problems with a Landi Renzo reducer. However, there are many more and not limited to for example – antifreeze leaks. Landi Renzo’s reducers are good, but there are many more on the market that are better, or just cheaper doing the same job. 

Common problem is the Pressure Sensor to go bad. If it is branded as Landi Renzo (has logo on the part), it is prone to failure and should be replaced with the Bosch type. If you do have the Bosch or Sensata HD sensor, please check via software if pressure readings are correct. If the pressure reading is ‘n.a.’ / ‘n.d.’ or too low (below 0.6), switch the engine off and pull the hose to the injectors out to see if it has pressure in it. If it does, you most probably have a pressure sensor fault. If it’s not, proceed to the next topic.

The first thing to do is to check if all electrovalves are opening. They produce a really loud click as they open. Usually there is one on the lpg/cng tank in the boot and one in the engine bay, mounted on the reducer or near it. Listen carefully as the gas system switches if they are opening. If they are opening, but still have no pressure – open the filter and see if its not clogged. Use common sense to see where the pressure is at, assuming you have gas in the tank, the first place to check is the tank valve, then the front reducer valve and finally if the reducer is not clogged or bad.

Some Landi Renzo systems do not have Water Temperature sensor and rely only on LPG/CNG temperature sensors. This way your system may switch on late, but not later than 50c temperature of the engine. 

The most common configuration is to have LPG/CNG Temperature mounted on the injectors (combinated with the pressure sensor) and Water Temperature sensor mounted on either one water hoses going to the reducer. You can use the software to see which one is bad. Sometimes you may have to wiggle the cables lightly to see if it will change its values. If it does – it is bad.

We are aware of OEM systems and how they work, but its more complex than that. Please reach out to us with your ECU code and type of problems you are having so we can discuss what can and what you can’t do. Some OEM installs include CAN-BUS lines and removing the LPG/CNG ECU may cause problems on petrol, because they are paired together (or married) and will require additional coding to your PETROL ECU in order to work properly (OPEL/VAUXHALL).

You can replace Landi Renzo MED injectors in the following ECU’s:

Landi Renzo Omegasbefore version 3 you can use anything, after version 3 (unlocked) you can switch to A.E.B. injectors for budget ones.


Landi Renzo LC02 – you can use only A.E.B. or Lovato K/J for budget injectors.


Landi Renzo LSI-NSI – you can use anything you want, file is programmable.

What type of components to use for repair?

Best components used for repair

After 5 years of changing Landi Renzo injectors, we have found the following injectors to work the best:

  1. HANA H200x – This injector rail has very close parameters of Landi Renzo and usually takes minimal effort to tune. It is the best option to choose if you have the budget for it and have more than 200,000km lifespan if the system is maintained properly.
  2. VALTEK Type30 – This is the most popular injectors along with RAIL IG1 that will work correctly with Landi Renzo systems. They often last more than 50,000km, but recent versions show calibration problems (self-tightening rubber o-rings) and may need readjustment after 10,000km or less.
  3. A.E.B. Polymer – if you do not want to program or ‘hack’ any configuration files, this is the way to go. Either having old Omegas ECU, you can update it to latest to support A.E.B. injectors and mount them, then auto tune them. They last around 100,000km or more.

Landi Renzo’s reducers are good enough theirselves and if you have the budget – throw in the same one, as it will save you time. But there are many other options that will also work.

  1. KME TUR6 – This reducer is the best to work with Landi Renzo systems, as it uses flap regulation for idle pressure and is very efficient at heating gas, even in cold conditions. It does not feature an integrated valve, but you can reuse the old Landi Renzo one. It is rated for 204bhp, so it can be used in 6 cylinder variants as well.
  2. Autogas Italia 140kW – this little tiny budget reducer is able to provide around 160hp (non-turbo) and is very easy to install, because of its small size. It features an integrated valve, integrated filter and elbow antifreeze inlets. If you’re on a budget – this is the way to go!

If you have a failed Landi Renzo pressure sensor, DO NOT buy a new one just like it. Buy and install the Bosch version, as it is more reliable and should last throughout the end of your system.

BOSCH Pressure Sensor code: 0261230373.

You can order it on every auto parts store.

Most probably you wouldn’t want to go for a new Landi Renzo ECU, because of its price. But if you have a 5-6 or 8 cylinder car, you may consider direct replacements offered by A.E.B., such as REAGAS, DigiTronic, AEB itself, GasItaly and much more. If your ECU is 5-6-8 cylinder, the wiring harness can be left untouched, just replace the MAP and GAS switch and you should be good to go. 


If you have 4 cylinder vehicle, consider using other ECU kits, such as KME, LPGTECH, REAGAS or DIGITRONIC. You will be better off replacing the ECU with another one, DO NOT bother buying new one from Landi Renzo. It will save you nerves. 


If you are not sure how to change the ECU with the installation, write us – we will tell you where to wire everything and get it up and running in no time! 🙂

Common purchase queries answered

Orders and Shipping

We are a digital (virtual) store, selling virtual goods. You will receive your product once we confirm your payment. This can take up to 12 hours.

We will always provide you a fresh working link in your ‘My Account’ area. Just click on Downloads and it will be there, every time!

Most likely yes, but please, please be aware that we have our own lives and jobs to do. We may not respond immediately, but we will help you diagnose your issue and recommend you what to do to repair it. You must know that our staff can communicate in English only, so if your English language is not fluent, we will have a hard time understanding you. E-mails that are in other languages except English will be ignored.

If you need to swap an item

Returns and Exchanges

We do not return money to prevent frauds to our hard work. Please have that in mind before purchasing anything from us. If for some reason you cannot connect to your ECU, due to bad communication cable or bad ECU, we are not accepting any refunds. Our product is tested more than enough throughout the years for us to know its working. We will, however, help you connect to your ECU in case of problems.

If you can prove us that you have ordered the wrong item on our website, we will happily swap it out for you if you are willing to pay the price difference. However, if you bought the more expensive item and you need cheaper item, we will not restore the difference, but we will help you for free instead.

Still have questions? Use our support form and receive 1-day answers!

Please share with us your ECU model and what are you trying to do with it.