ECU diagnostics

[NissanGQ4.2]

Right - now all I have to do is learn how to use it!!! LOL ... no error codes at least!! The guages are all good, but not much use to me if I don't know the "ranges" each item is supposed to be in ... can't wait to learn though!!

for someone that gets good deals on computers, that looks like 1 dusty old laptop!!!! when you work it all out, let me know. Not sure on injector size in cc's per minute, looking it 2 it, but not much info on the net about it unfortunately.

[Bigrig]

Doesn't the ECUtalk give you the abillity to play around with mixtures and ignition timing to some extent? If it does you just know he won't be able to leave it alone!

Tony

Not that I'm aware of as yet - doesn't look like it though - other programs might ... I'll start looking!!! LOL

[Bigrig]

for someone that gets good deals on computers, that looks like 1 dusty old laptop!!!! when you work it all out, let me know. Not sure on injector size in cc's per minute, looking it 2 it, but not much info on the net about it unfortunately.

That dusty old laptop is a HP Probook something or other my furry little friend ... like I care though!!! It works!! Can't wait to figure a bit more out with it ....

[YNOT]

Doesn't the ECUtalk give you the abillity to play around with mixtures and ignition timing to some extent? If it does you just know he won't be able to leave it alone!

Tony

I was right. I just checked ECUtalks website and found this;

"Adjustments
Important – USE ADJUSTMENTS AT YOUR OWN RISK.
Adjustments are available for fuel and ignition timing on petrol vehicles only. Adjustments are applied ‘across the board’ and starting in v2.03 firmware, are active whilst on one of the main sensor/trip meter screens, along with the adjustment screen itself. The adjustments utilise the ‘active tests’ available via consult. Note: It is unknown if there are any situations/conditions that the ECU may not apply the active tests, as the intention of the active tests is primarily for diagnosis.
Fuel % - Adjusts the percentage of nominal fuel (that would otherwise be used) that gets injected. E.g. 95% means the mixture will be leaner, 105% means it will be richer.
Ignition Timing – Adjusts the ignition timing in advance (+) or retard (-) of nominal ignition timing the ECU would have used otherwise. Note: All cars support retarding timing, but not many support advance of timing."

Tony

[Bigrig]

Oh Lord ... I am going to break something!!! LOL

Thanks Tony

[Bigrig]

Tony, question if I may.

My rig's timing is advanced 4 degrees (is that the terminology?), and apparently being dual fuel, I was told the engine will "ping" if it's advanced too much in favour of gas. What does this actually mean (the "ping" bit) and do you reckon if I advanced it using ECUTalk 1 degree at a time till I find "the sweet spot" that it would affect performance that much on gas?

Ok, ok ... Two questions!! LOL

Thanks in advance.

[YNOT]

1a (short answer), Pinging is the sound the engine makes when the timing is over advanced.
1b (long answer), Normally in a 4 stroke petrol engine you set the ignition so the spark occurs a couple of degrees before top dead centre (BTDC) on the compression stroke, which means that the flame front in the combustion chamber is propagating as the piston finishes rising in the cylinder. Setting it this way ensures that maximum combustion pressure is achieved at TDC for best power. If the timing is over advanced maximum combustion pressure will occur as the piston is still rising on the compression stroke which causes a knocking or pinging sound as it tries to push the piston back down the compression stroke rather than down on the power stroke.

2, High octane fuels like LPG can handle a bit more advance, the downside being for dual fuel cars like yours that you have to comprimise the timing for both fuels. With the ECUtalk you will have the abillity leave the distributor timing advanced for LPG but retard the timing back to normal through the ECUtalk when you run on petrol so you don't have to comprimise for either fuel.

Tony

[Bigrig]

1a (short answer), Pinging is the sound the engine makes when the timing is over advanced.
1b (long answer), Normally in a 4 stroke petrol engine you set the ignition so the spark occurs a couple of degrees before top dead centre (BTDC) on the compression stroke, which means that the flame front in the combustion chamber is propagating as the piston finishes rising in the cylinder. Setting it this way ensures that maximum combustion pressure is achieved at TDC for best power. If the timing is over advanced maximum combustion pressure will occur as the piston is still rising on the compression stroke which causes a knocking or pinging sound as it tries to push the piston back down the compression stroke rather than down on the power stroke.

2, High octane fuels like LPG can handle a bit more advance, the downside being for dual fuel cars like yours that you have to comprimise the timing for both fuels. With the ECUtalk you will have the abillity leave the distributor timing advanced for LPG but retard the timing back to normal through the ECUtalk when you run on petrol so you don't have to comprimise for either fuel.

Tony

Thanks a million mate - on the last paragraph I'm not quite with you. Are you suggesting I use ECUTalk to advance it for gas, but then I have to use it also to retard it for fuel?? That is, I'd have to have the unit in the car all the time??

[Bigrig]

Sorry, one more - so in advancing it for gas, as per my original question, should I do it 1 degree at a time and test drive after each change to find how far I can advance it???

[YNOT]

Thanks a million mate - on the last paragraph I'm not quite with you. Are you suggesting I use ECUTalk to advance it for gas, but then I have to use it also to retard it for fuel?? That is, I'd have to have the unit in the car all the time??

Not quite, there are 2 ways to do it.
1, In post #86 you said your timing (distributor timing) was advanced 4 degrees (I'm assuming that was done so it runs better on LPG). If you leave that as is then your base timing is for gas and you then ECUtalk retard it 4 degrees for petrol.

2, Reset the timing back to standard so your base timing is for petrol then ECUtalk advance it 4 degrees for LPG. That is how I would do it.
If you are finding that it runs OK on petrol at 4 degrees advanced then leave it there (as petrol base timing) and advance it 1 or 2 degrees at a time for LPG until it just starts to ping - turn the radio OFF for this, then retard it 2 degrees to stop it pinging. If an engine is allowed to ping for too long engine damage will occur so be careful.

Tony