Dopefish

Ok looks like a was too much worried about the voltage of the wideband lambda, i've found a bosh datasheet and it's not as rich as i thought But what about these parameters after a short trip? They are DTV1, DTV2, FRA1 and FRA2. Somebody told me that they should be DTV=0 and FRA=1 or very close, so i may have vacuum leaks and fueling or airflow problem if the lambda readings are reliable. What should i check? My workshop said it's not a problem, if there are not fault codes the values are within parameters which could make sense, but in the past i had other problems but no error codes...

Hi! The emissions are above the limits as expected, but the test was done with all the 4 lambda and the minicats/lambda faker (those that sells alfisti.net), so can't tell the difference. I don't understand if you are saying that this values are normal for the jts, but what AFR corresponds to 600 mv of the wideband lambda? About the power, i hadn't time to do some repeatable tests, but as can i see i've lost from 10 to 20 kg/h of airflow at high rpm from when i had the valves full of carbon buildup! If this is not MAF related (new maf after the rebuild) i think there is something wrong with this engine.

Ok i finally had time to fit the post cats lambda and run some test. Note that i didn't use the original ones but the twins spark version (with 2 meters long cable) and 2 small minicats (can't tell if they are really useful). I performed an ecu reset with multiecuscan and after some days logged some data. I can see car seem to run a bit better, not a lot of petrol smell on exhaust like before except at idle because now i have some missfire, like when i had the cats. Voltage readings on the post cats lamba are like when there were the cats, maybe they were almost dead? Pre cats lambda readings are changed, in comparison with no lamda, a bit on the rich side in on average(but the same when i had the cats) but as i said earlier doesn't seem the case since the much less smell of petrol on the exhaust, unless i had not reported missfires. At idle it looks leaner at 2.4-2.5 volts instead of 2.2 v, but i have some missfire expecially when water temperature gauge is around 70° celsius (same with cats). What bother me are the readings at high rmp, the lambda had made no difference, i still have very low voltage, as low as 500 mv, don't know what afr is but i think it is too rich. Here is an image with some values, in the column B are the pre cat lambda 1, in column C pre cat lambda 2, in C are rpm and in D airflow: If i remember correctly it's not normal. Would still be a problem caused by the mismatched lamba and minicats? But all the other reading had similar values when there where the cats. Rebuild hadn't gone well? Exhaust isn't as good as stated? Any suggestion?

Hi, i need some info for the stock cams of the 2.0 jts. Do somebody knows the timings and lift of these cams? I also need the diameter of the base circle and the maximum "recovery" of the lifter, because i saw some aftermarket cams and have a smaller base circle then the stock cams (to allow higher lift) and i would be sure that are not out of tolerance. Finally, the part code of the camlocks would be useful, since i have red that were changed after the recall of the intake camshaft of the firsts engines produced and would be sure to get the correct ones to check if the timing is correct. Thank you!

Ok, 'im working on it Some days and the lamba will be refitted Thank you!

But are you talking about the post cat lambda? The values i've reported are for the wideband pre cat lambda, if i remember correcly a datasheet i red years ago, in the jts they should have approximately 1.5v for stoichiometric AFR, 2.2v in lean burn mode 20:1 AFR, 4.2v when fuel cuts off (off throttle over 1500 and under 4500 rpm), and 1.0v when rich (12:1 AFR?).

The intak Is All stock, air filter included. I'm using Alfaobd demo for Android Because it's more practical but i'll check with MES, so I Can also log More Then 4 sensors. Shouldn't be the max value of the lambas 4.5v when no fuel is injected?

Thank you again smaky! I will do it as soon as possible (so, will not be soon...). What do you think about lambda 2 at 3.5v when off throttle and why only the second? Is it part of the limp mode or maybe it's a faulty lambda or connector? By the way, after the test with the manifold disconnected i had some effects. The idle is less lumpy then before, the lambda readings are around 2.2v (maf reading 16kg/h, more stable then before that was between 15-17 kg/h), it's worse when the temperature gauge reads 70°C but it was always worse then usual at that temperature. I have less "go down to 500 rpm" when clutch is pressed and i can also have less problem to maintain in neutral costant rpm below 1500, before it started to go up and down from 1800 to 500 rpm. I have had this problem since i bought the car (not new), now it didn't disappear but when engine is at working temperature rarely happen. Am i hoping for nothing and it's a coincidence?

Thank you very much Smaky! They didn't do full head rebuild, i've checked exactly what was done, on the top end they only cleaned all the valves, valve guides and seals are the original... the piston where cleaned and fitted new rings, they changed the rod bearings but didn't changed the big end bearins (i told to do also them! f***!). And the injectors are new, i forgot to mention. On sunday i've done some testing with the manifold disconnected (unplugged the electrical contact) and didn't notice remarkable differences, but i had very little time testing and could't do before vs after test consecutively, but when i reconnected the plug, with the engine off and the keys in my pocked, i've heard an hissing sound and something moved, don't know if it's normal but i think it's a sign that the solenoid works. Another strange thing i've seen, and is not related to the manifold disconnected or not, is that when i'm off throttle and the fuol cut-off should engage, only the voltage of the lambda 1 raises to 4.0v, the lambda 2 is at 3.5-3.6v. As for the maf reading, before the rebuild (or the semi-rebuild) the reading weren't erratic on high revs, maybe the new maf is faulty? I will put the missing lambda, but the exhaust has only one hole. Is possible to split the signal cables of this lambda to the other connector and use the other lambda only for the heater resistance? Will it temporary solve the overfueling problem before i do the remap? I will stay down with rpm for the moment :Big Grin: Or should i put one of those mini cats on the lambda to foul the ecu?

I've seen that the only 2.0 JTS expert in the world is here, hope you can help! Engine is a 2004 2.0 JTS (i know, why did i bought it? ) with 88k miles, engine rebuild, intake valves cleaned, changed almost all sensors (upstream lambdas, maf, map, phase sensor, ecc...), spark plugs, alternator, new belts and tensioners. Trashed the cats and put a decat exhaust, no downstream lambas, light flywheel. Didn't remap yet. The problem is that the ingine doesn't go well, low torque is non existent until 2800 rpm (or very close to that...), the exhaust was blamed but reading on the internet should't shouldn't be the case with this exhaust. Then at this rpm there is a surge in torque and engine seems to go well until 5200 rpm (or close...). At this rpms then the lambda readings are way too rich, starting from 0.9-0.8v at 5200 to 0.5v at 5800 rpm (or close). After that all of a sudden they return to 1.0v. The maf readings are low (lower than before the rebuild, with the intake valves full of carbon buildup) and strange, as if the airflow is irregular while the rpm goes up, for example you can read something like this: ... 330 kg/h 340 kg/h 320 kh/h 350 kg/h 360 kg/h 340 kg/h 370 kg/h ... and the maximum was 390-400 kg/h at 6500 rpm (didn't reach 7000 rpm while testing), but before the rebuild I remember 410-420 kg/h. Idle is not very regular but not very bad, but sometimes there is a drop to 500rpm while pressing the clutch pedal, and if coasting in neutral rpm goes up and down around 850 rpm few times. Before the rebuild i've had the same problem but much worse and with some engine stall. The lambda voltage at idle are 2.3-2.4v instead of 2.2v (misfires? intake leak?), i've had these readings even before and never saw 2.2v but for few days some years ago, without changing nothing. There is a small oil leak around the variator solenoid, the variator doen't rattle, engine oil is 10w60 shell elix ultra. So, since there seems to be a coincidence between the rpm i've problems and the rpm where the intake manifold should engage/disengage, is it possible that it would stick to the long position? I've red that it is spring loaded and if damaged it will stay to the short position, so i should have midrage lack of torque instead. Is there a way to test it? Or maybe the oil leak on the variable solenoid seal would cause the problem? Or what is happening to this poor engine? Wrong cam locks used for the cambelt change? What else can i check? I've a full version of multiecuscan if needed. For the mechanic it's just fine, if it's fine for a 2.0 to have less power and less low down torque than a 1.6... please help! Thank you!

Hi! I've come here very often from google search and i've found very precius informations, one of the few places where you can find real solutions to problems! Now I hope you can help me!