Which injectors???

[BYD1380]

Hi all,

I'm having problems with my 2001 Passat, see below

http://www.lpgforum.co.uk/viewtopic.php?f=28&t=12998

Basically I want to try different injectors. My 3 previous cars have had magic jets installed. I'm having problems finding a set.

Why are the OMVL's much cheaper? There has to be a reason. Could someone recommend me a good injector? My car runs best at a higher LPG pressure, maybe the OMVL'S are not suited to my engine?

Ivan

[Tubbs]

Omvls are a pretty good injector as it goes.
You run them either inserts out at a lower pressure or inserts in at a higher pressure.
So it should be fine.

[tomas]

I using omvl injectors over 3 years...no problem at all just they are a bit noisy...

[classicswede]

I have been using OMVL injectors for over 10 years.

[BYD1380]

Cheers for the replies.

Is it possible that the OMVL's are just not suited to my setup. 500cc per injector? I've used the Magicjets in the past for my higher power setups, 2.2turbo S6 (360bhp) and 1.8T 225bhp. Even those engines were <450cc per injector.

I'm just clutching at straws to try and get some economy out of the Passat, at the minute it really wasn't worth the conversion to LPG.

Ivan

[Pike]

I noticed that Tinleytech now sell Magicjets

[BYD1380]

Cheers, I found a set, will fit them on Thursday once I'm back and keep this thread updated.

Ivan

[LPGC]

Changing the injectors shouldn't help at all. The only way changing the injectors will help is if you currently have a very poor map, you will have to remap it when you fit new injectors and the remap might help. There are hundreds of Passats with OMVL injectors, converted a few dozen with OMVL injectors myself over the years!

As you were advised on the other thread, it is the misfiring etc that is most likely to be causing your problems. Could be down to bad mapping and if it was mapped with a misfire it cannot have been mapped properly, or could be down to the ignition system.

Had a guy here today, I fitted a new changeover switch on his car a few years ago, came in saying it was using too much gas and sometimes misfiring. Turns out he'd fitted 'LPG special' Belko plugs that the guy at Euro Car Parts advised him to buy a few months ago. I asked him how long it had been misfiring on gas for... a few months!

Simon
Lpgc

[BYD1380]

Cheers Simon,

I'm using new leads and new NGK plugs. I really wouldn't describe it as a misfire, just a hiccup. It is pretty much away now, but that's running 1.25 bar. Each time I change pressure I carry out a full remap. I have redone the petrol map also.

I have the maps perfect on the LPG nevo 4 software. I have a full version on VAGCOM and fuel trims are within 1%.

Im just clutching at straws. But need something sorted. Last tank was 24mpg.....

I'm back from holiday tonight and hope to fit magicjets tomorrow, after that I'll keep you updated.

Has anyone used NEVO software? There is a function for acceleration enrichment, mines disabled, anyone know how to activate it?

Ivan

[andy evans autogas]

I have used Nevo 4 since it came out and have never had a problem or a fueling issue, but I do know of installers that have had fueling issues with OMVL reg injectors. I mentioned earlier to check that it is not running out of phase ? Make sure the LPG injectors are matched with petrol injectors, it seems that pressure of 1.25 or thereabouts is quite high for your car. I would expect pressure around 1 bar and nozzles around 2.5 /2.6 mm

[LPGC]

Hi Andy, Interesting, I've never known issues with Nevo and OMVL injectors, any ideas why there would be an issue? As with other similar performing injectors I'd expect there to be a little bump on the map, sharp rise between about 3.5ms and 4ms, holding until about 4.8ms using OMVL's but this shouldn't be an issue. I agree with your suggestion on pressure and nozzle sizes, wonder if the owner checked the nozzle size or stuck with the default nozzles - OMVL Superlights can arrive with smaller nozzles fitted, you don't always know what nozzles will come supplied but there are often 2.5's in the box if not fitted as they come.

Do we know what working pressure is set in the calibration, what pressure the reducer is set at, nozzle sizes, etc?

BYD1380, what's the petrol injector tickover duration whilst running on petrol, whilst running on gas, and gas injector tickover duration (engine warmed up and running smoothly for all 3 checks)? I'd expect figures to be around 3ms, 3ms, 4.5ms respectively.

Simon
Lpgc

[andy evans autogas]

The problem isn't with the Nevo 4 and the OMVL injectors,but more just the OMVL injectors there just a bit slow and clunky (if you know what I mean) .. Andy

[LPGC]

Hi Andy, think I know what you mean... Compared to MJ, Hana, Matrix etc injectors they're slow and are a bit noisy, I don't use them on performance engines but I find they're very reliable and probably the best performers at the price whilst the side outlet design can be useful on some applications. I rate them better than some that cost twice as much in terms of linearity, flow (with biggest nozzles) and certainly reliability but have noted that firmware in many ECU's applies an artificially high offset figure when OMVL injectors are selected and this can skew the map. I'm not trying to make out OMVL's are a great injector or anything but I think they're better than they're more linear than they get credit for. In cases where the ECU's offset is above the response time of the injectors the multiplier at the bottom end of the map will be lower than expected and with a fairly flat may any rise in Pinj will not fully be reflected in Ginj, this sometimes giving the impression of a less responsive injector. I can't remember what I calculated the offset to be on the KME Nevo's when OMVL injectors are selected but offset can be manually adjusted on KME Diego ECU's.

Simon
Lpgc

[BYD1380]

I have used Nevo 4 since it came out and have never had a problem or a fueling issue, but I do know of installers that have had fueling issues with OMVL reg injectors. I mentioned earlier to check that it is not running out of phase ? Make sure the LPG injectors are matched with petrol injectors, it seems that pressure of 1.25 or thereabouts is quite high for your car. I would expect pressure around 1 bar and nozzles around 2.5 /2.6 mm

Hi Andy, Simon

Thanks for the replies, what do you mean out of phase?

My Magicjets still haven't arrived, prob bad weather. I checked a few things tonight.
My nozzles are 2.5mm, I checked each one, with the blunt end of a 2.5mm drill bit. Lines into the inlet manifold are short and free from blockage.

Simon:

Injections times are as follows

Running on Petrol : 4.25ms
Running on GAS: Petrol 4.25-4.35 GAS: 4.4-4.5

Working pressure in the calibration is set to 1.2 bar (1.1 bar originally)

Ivan

[andy evans autogas]

Looking at your inj times I would bring pressure down to around 1.1 on the regulator and take the working pressure down to about 0.8 / 0.9 ....
As for out of phase. Make sure that gas inj no1 is matched to petrol inj no1 and so on ....

[LPGC]

Not sure if BYD1380 listed the information asked for - BYD, are you saying the engine idles on petrol with 4.25ms injection duration? That's going to be wrong with a fully warmed engine and no load. Please repeat the test with engine fully warmed and having been running for 10 mins, no electrical load, out of gear. Need to know durations: Petrol duration running on petrol, petrol duration running on gas, gas inj duration running on gas.

Simon
Lpgc

[BYD1380]

Simon,

That was it warm, no load etc, lights, radio, heater/AC all off.

Ivan

[Tubbs]

That is incredibly high petrol times......

[LPGC]

That is incredibly high petrol times......

Agreed Tubbs mate. We might expect 4ms at idle on a Bosch injected P38 but not on a Passat, would expect just over 3ms idle duration on a Passat with no load and fully warmed engine. There must be some other problem. BYD, is the engine warning light on? Have you had an OBD code reader connected? If so, is the engine running closed loop under these conditions? What are the ECT, Maf , Map and Lambda readings under these conditions?

Simon
Lpgc

[Gilbertd]

Are you sure your lambda sensor is working? A petrol ECU running a fail safe map would give injection times that high at idle but would also bring the MIL on. Does that come on when you turn the ignition on or has someone taken the bulb out?