misfire and hesitation in open or closed loop... no o2 voltages

[xploder98]

Well its that time of the year I guess. Dropped the girl off at work, when I started it up to leave it started sputtering and stumbling and even died a couple times as I was tryin to keep it alive at like 200 rpms! Now it idles by itself fine. but wether its warm or cold, open or closed loop I have a rough idle and a terrible hesitation during acceleration. Vacuum is great, fuel psi is good, pretty sure there's no intake leaks. Idk wuts wrong. I've had the p0171 and 0174 for a couple months now. Since the last time I changed injectors o rings, coil, intake o rings and gaskets, fuel rail gasket and egr gasket and egr tube o ring, o2 sensors, both. I do have one.of the worst gas tanks u ever seen. Could my problem be a clogged injector(s)? Just changed plugs and wires. This kinda happened instantly and does it in closed or open loop. That makes me think its not a sensor used in only a single mode, open or closed loop. Gonna check all sensors tomorrow with multimeter for the heck of it. Gettin new gas tank Monday and gonna take injectors and fuel rail to a buddys house for ultrasonic cleaning then get injectors flow tested. Before I do all this, anyone got any other ideas? I've got some freeze frame data and a failed on board monitor test. Will post the pics of the data in another posting in a sec. Sorry such a long post. Just tryin to give details

 

[xploder98]

Havin a lil trouble posting pics. Will have em up in the mornin. Basically long and short term FT's are -100% and all my o2 sensors have 0 voltage

Here's my on board monitor test that I failed. Still learning how to read these.

On board monitor test
Test $10 data
Component id: 33
Module: $ 10
Test value: 65535
Min limit: ----
Max limit: 51
Status: fail

 

[budwich]

forget the ft values and o2 values.... a few posts ago someone posted similar results for 98..... basically "bad programming" between your reader and odbii interface.... "known issue" on some units.

clean the maf... check for air leaks using the spray technique.

 

[xploder98]

I've used almost a whole can checking for leaks and I know where to look. I wouldn't think bad programming would happen out of nowhere. Not sayin its impossible. I've replaced and cleaned the maf with no luck. I pulled my computer and took it apart to inspect after hearing about melting and leaking capacitors but everything looks good. When i unplug the maf with engine running i can tell its going into open loop but its still missing and hesitating. I guess just because fuel psi is good doesn't mean the injectors are doing there job. And with The crud in my tank I can see a chunk plugging an injectors. And that can happen right away and will do the same thing wether its in closed or open loop. This sound plausible? Like I said I got one of The worst tanks ever. It sat for about 4 years with gas in the tank. A year and a half ago I cleaned the tank as best I could but I'm sure there's still crud in there. I put Rebuilt heads and block and so far have only 9k on em.

 

[2000StreetRod]

defective scanner

Which scanner are you using to read the fuel trims? What budwich was trying to explain is that certain scanners are unable to read the 1998 Explorer fuel trims and report -100%.

What were your fuel pressure readings at idle with the fuel pressure regulator vacuum line connected and disconnected?

 

[xploder98]

Sorry. I realized that, as I hit the submit button the scanner I'm using is the Creader V. Fuel psi is 29-30, 39 with the regulator/damper Vac disconnected. I did get it to drop to about 23 for a split second while revving it.

 

[xploder98]

Your right about the FT's and the o2 sensor voltage readings during live data view but what's weird is, when I clear the codes and the code pops back up I get freeze frame data. And on that freeze frame data it gives me fuel trims... Correct ones. Here's my freeze frame data for my p0171 and 0174

Trouble code: p0171
Fuel sys. sta b1: CL/ Using Ho2's
Fuel sys. sta b2: ----
Calc Load: 32.15%
Coolant temp: 70 degrees celsius
St Ft b1: 14.83%
Lt Ft b1: 29.67%
St Ft b2: 29.67%
Lt Ft b2: 29.67%

 

[2000StreetRod]

compatible car makers

I found this:

Car Maker: Audi, Benz, BMW, Chrysler, Citroen, Honda, Hyundai, Nissan, Porsche, Renault, Seat, Skoda, VW

P0171 System too Lean (Bank 1) passenger side

Lean condition procedure

 

[budwich]

based on my "readings", those values appear to indicate a significant air leakage somewhere or an "out of whack" maf. What is the input air reading? The temp reading seems a bit low... almost like a bad thermostat (stuck open)... or the engine hasn't warmed up yet.

 

[xploder98]

It doesn't go over 1.0 b/m unless I get on the throttle. Intake temp isn't high. Coolant ten is at lowest 177 at highest 207

 

[budwich]

70 c is like 160f which is pretty cool if the engine had some run time already at the time of the cel hitting. Its too bad your interface doesn't give accurate run data at idle for trims... that would be helpful additional information.

guess i would be interested in someone understanding of the "balance" on the trims. I would have expected them to be some what similar IF all things were operating correctly (ie. air intake, injector times, etc), such that there wouldn't be a big difference between the sides. That might be another clue that the is a leak on the side with the greater trims... my guess... or perhaps a cylinder issue on that side in terms of combustion (ie. lower compression ratio perhaps).

 

[xploder98]

Ignition coil primary resistance is from 0.3-1.0 ohms. All three were 1.6 ohms
Ignition coil secondary resistance from 6.5k-11.5k ohms. Mine were 13.28, 13.20 & 13.38

You guys think this is too much resistance?

 

[2000StreetRod]

typical coil pack

Ignition coil primary resistance is from 0.3-1.0 ohms. All three were 1.6 ohms
Ignition coil secondary resistance from 6.5k-11.5k ohms. Mine were 13.28, 13.20 & 13.38

You guys think this is too much resistance?

I doubt that your coil pack is the source of your problem:
coil specifications?

 

[xploder98]

Me to. Took another freeze frame shot...

Trouble code: p0174
Fuel sys. sta b1: CL/ using h02s
Fuel sys. sta b2: ----
Calc load: 35.68%
Coolant temp: 158.24 degrees f
S.t ft b1: 42.17%
L.t ft b1: 2.33%
S.t ft b2: 42.17%
L.t ft b2: 2.33%
Rpm: 1831.75

About ten min after words I wrote down some live data

Intake temp: 87.8 degrees f
Maf: 0.64lb/m
Throttle position: 18.03%
Engine speed: 793.25 rpm
Coolant temp: 181.39 degrees f
Calc load: 41.96%
Timing: 10 degrees


This live data was taken at idle. Notice i have a 41% load at idle, and 18% throttle. this sound right? What about maf? Does that look right for idle?

 

[xploder98]

Once again I cleared the codes and took another freeze frame. Not the 2 banks have different trims again. Idk wuts going on. Think im onto something when I single out injectors and or fuel?
Here's the results

Trouble code: p0174
Fuel sys. B1: CL/ using h02s
Calc load: 26.66%
Coolant temp: 194 degrees f
S.t ft b1: 31.23%
L.t ft b2: 18.73%
S.t ft b1: 35.14%
L.t ft b2: 24.98%
Engine speed: 2029rpm

Anybody? I'm hopeless

 

[2000StreetRod]

MAF Sensor Test Procedure

MAF Sensor Test Procedure

Your MAF at idle seems reasonable.

Your spark advance at idle should be around 20 degrees instead of 10.

Did you replace your fuel tank? Do you have rust in the tank? If so, they are almost impossible to clean for reliable operation. Stalled '99 4.0 SOHC Explorer.

 

[xploder98]

The new tank'll be here today. Gonna take injectors and possibly fuel rail to a buddys for an ultrasonic cleaning. Then find somebody around me that flow test injectors. I'd also like to find somewhere close by to get a smoke test done. My buddy used to have a smoke machine. I don't know Wut he did with it.

 

[xploder98]

I wish I only had rust in the tank. I have some god awful unearthly substance in mine definately ready for the new

 

[budwich]

I went out on my 96 and ran a few minutes just to compare things.

My advance was at 10 for some of idle then after a bit of run time and also some throttling to bring up rpm to 2k (of which the advance went to 20), it would hang around at 14-15 for a bit but eventually dropped back down to 10 at idle. Not sure if that is OK or not... just reporting.

My concern is still your fuel trims. Mine appear to hang around at "0ish" at idle and 2k while the short terms move to 5-7% ish.

Your trims seem high and out of whack ("unbalanced") especially during the cel event. My guess is inadequate fueling because of pressure issue from clogged filter or clogged pump intake. IF you had a injector issue, I would think you would be seeing misfiring ids for a given cylinder.

 

[xploder98]

The weird thing is i can feel a constant missfire, from injector(s). My pressure is good but im more than sure the pump screen/net is caked with crud. Just changed fuel filter day before yesterday.