@chucktobias Hi; No I have not looked at live data yet. What am I looking for? thanks

@jack-d You're looking for any parameters that are out of whack. (Fuel trims, ignition timing, sensor outputs, system voltages, etc.)

@chucktobias Alright, thanks. I'll give her the live data look in the morning.

@chucktobias Update on my Ford Windstar 3.8L V6. I combed over the engine looking for vacuum leaks and elec connectors. I found 2 semi loose vac connections. One loose end of a short air line from intake manifold to the top of the fuel pressure regulator. and another loose end on an air line from behind the back 3 cylinders to the EGR valve. I ran the engine until warm with my scanner connected. The engine seemed to run even more rough than before. My Live Data looked consistent except for the value of SHRTFT B1 S2 showed N/A. No actual number shown for that sensor. I replaced both downstream O2 sensors 3 days ago. Thanks for your assistance. Jack

@chucktobias Update 2 I looked at live data again and found SHFT1 is bouncing around in negative ( -.06 to -15) The other 3 LTFT1, SHFT2 and LTFT2 look more in the normal range. Also a code pop up Misfire cyl 5. I had that code once before and replace cyl 5 plug. I checked #5 yesterday and it looked fine although a bit on the lean side

@jack-d Those are some decent clues. Short term fuel trim will bounce around but the -15 is saying too much fuel is being delivered. Possible leaky injectors. Check all plugs to see if one or more is getting carboned up from excess fuel. I would also expect to see a negative trim percentage on the corresponding long term trim, though not necessarily that high. Does upstream O2 sensor output look OK? When you replaced the O2 sensors did you use OEM parts?

You might also want to check compression on that cylinder #5 that's experiencing misfires. (There should be misfire counts for each cylinder in the live data assuming the ECU provides that level of data.)

@chucktobias Hi Chuck; I just finished putting new ignition module but that didn't help. Not much for the part but took quite a lot of time. I cleared the code "misfire cyl 5 and it has not popped a code yet.. I feel like the search is starting to point at bad injector(s)? I would think a bad injector would throw a code but the van is an 01 so maybe it has minimal info avail on the ECU?

@jack-d A code is not registered until a problem reaches a certain level and you may experience symptoms before that occurs. This is why "no codes" is not necessarily helpful in diagnosis. Injector problems will typically show up in fuel trims and also affects spark plug condition. You can "read" the plug's condition to get an idea of what's happening in the cylinder.

@chucktobias Hi; the engine is so obviously missing that it seems like it should throw a code? I have had a 'misfire' code twice in the last week. Both times it says Cyl #5. I am going to purchase one new injector and try that on Cyl 5 and see if it clears?. I have looked at that plug several times and it always has the light tan look of either running clean or maybe slightly lean. Thanks

@jack-d Before buying one why not swap the suspect injector with another cylinder and see if the misfire travels with it? If you do replace it be sure to use an OEM part.

@chucktobias Hi; Same problem exists today. I switched out #5 injector.not with OEM but close I hope. No change and I still have no value on shrtft B1S2 just an NA. I replaced that oxygen sensor. The old one was nearly white and powdery looking. Still no codes but I Had erased codes a day ago, so I still need to drive it until all the sensors come back on line. Thanks

@chucktobias The dead spot on B1S2 sensor is the side of the engine next to the firewall. So I will concentrate on that side today. Take the spark plugs out and read those first. I may find a dead plug? That would be nice because if it's a bad injector, that will prob be really hard to get to.

@chucktobias My best guess after seeing the B1 upstream O2 sensor covered with white powder and the spark plugs all showing signs of running LEAN, that it's not getting fuel properly on those 3 cylinders. I am not sure if this is a mechanical issue like plugged or failing fuel injector or an electronic sensing issue, or both? Any ideas? If I have to replace the 3 injectors on that firewall side of the engine, it will be a lot of work. I am going to try and drive the van enough to turn on the OBD sensors and see if there is a new CODE?

@jack-d If it were a fuel delivery problem I'd expect to see that reflected in the fuel trims. You might check your fuel pressure if you have not already done so just to make sure that's OK.

@chucktobias Yes the fuel pressure needs checking again. I did check it at first suspicious it was the fuel pump but I registered 32ps with pump running engine not running. Question: if the engine is off and setting for 8 hours, should the fuel pressure remain close to 30 psi? I have released the pressure twice recently and both times it has been very low, like a small spurt of gas and not a spray under pressure? Thanks

@jack-d There is supposed to be static pressure in the fuel system when the engine is off. You would have to look up the specification for how much pressure is supposed to be held. That's something which, if not working correctly, could make the engine harder to start after it's been sitting for a long time but it would not affect its operation otherwise.

You're having enough trouble with this thing that it probably would be a good idea to perform a compression test to make sure you're not battling an internal engine problem. (It is a nearly 1/4-century-old Ford after all.) You may be able to hear compression differences in the cylinders when cranking:

https://www.youtube.com/watch?v=bEmzih9MV7o&t=128s

You can also do a relative compression test with a scope by graphing current draw or battery voltage while cranking. (Of course a real mechanical compression test or leakdown test is best.)

@chucktobias Hi Chuck; I have a compression tester here. I was thinking maybe a borescope camera and look at the valves. It might be easier to take the valve covers off and run it to look for bad valves. I don't own a borescope. I guess the compression test would reveal bad valves in a cylinder? I'll give that a go. I just took a test drive to see if I can get a Chk Eng Lt to show up? I had my OBD scanner hooked up. It was missing bad and the Live Data showed consistent values except for SHRTFT B1S2 and SHRFT B2O2. B1 still registering N/A and B2 registering 99.2

@chucktobias Hi; Chuck; I have now replaced all 4 oxygen sensors. Here is a picture of how the tips looked on both banks 1 and 2 (upstream) sensors OK, I guess I can't upload a picture? Both sensors have a white powder looking color on the tip. I am guessing that means both sides are not getting enough fuel?

@chucktobias Evening friends; Update on the 2001 ford 3.8 v6. Still not running clean. I have tried checking the timing cams to see if they are off? Today I found a Utub video that explained how to check, set or replace and set the Cams via the CPS cam position sensor. He warned several times in the vid not to mess with the CPS until you have all the tools and info. Too damn complex for one, but I moved mine around several times thinking it adjusted like turning a distributor. I may be in deep doo doo? We'll see I'm hoping I didn't break internal parts? Dang!

@chucktobias Hi Chuck; I have worked the car half to death but the problem remains. Update on what I have done: I replaced the cam synchronizer, the cam position sensor and the crankshaft position sensor. I installed it per the instructions for this Ford 3.8L engine. It still is running rough. All 4 O2 sensors are replaced and I checked the resistance of all 6 fuel injectors. All 6 spark plugs are new. I could not check compression because I apparently do not have the correct cylinder fitting for a Ford? I can get the correct fitting but before I do that I have a specific question. I ran the engine today with my OBD2 scanner connected. It is not holding any codes but I have had to unhook the battery several times making the sensors mute right now. I did another Live Data specifically looking at the Short and Long Term Fuel Trims and the operation of the O2 sensors. All data points looked to be operating in the range EXCEPT the Short Term readings on both B1S2 and B2S2. One still reads N/A and the other one reads static 99.2. In your experience would that indicate that both Cat Conv. are not operating?? Thanks Jack D

Catalytic converters would not affect fuel trims. The only effect they're really have on how the engine runs would be if they are plugged up creating excessive back pressure.