|
|
Post by rockacello on Oct 12, 2018 10:38:26 GMT -5
Ok, now I have some weird sputtering from 1000 rpm - 2500 rpm, at WOT it runs great but partial throttle in that rpm range, it's complete dog and feels like it is running out fuel. It seems to be intermittent and it gets worse as the engine gets to temp. My plan is to check the following:
-TPS
-Fuel Pressure
-Grounds
-VAM
Is there anything else I should add to this list that is easy to check?
|
|
|
|
Post by Stinger on Oct 12, 2018 10:44:57 GMT -5
Scan for codes.
|
|
|
|
Post by rockacello on Oct 14, 2018 22:46:52 GMT -5
No codes, VAM and TPS showed normal values. Grounds were fine. I couldn't check fuel pressure.
Prior to my original post for this thread, the car had been sitting for roughly 8-9 months. Could sputtering be due to bad/old gas?
|
|
|
|
Post by Stinger on Oct 14, 2018 23:08:16 GMT -5
It's likely lean which is why it feels like it's running out of fuel/lacks power under those conditions. Since it's temp dependent it could be the ECT sensor, or it could be something that is ignored during the warmup / open loop process and only effects closed loop operation.
I suppose it "could" be old gas but I've never had it act that way. Normally old gas just loses its octane rating and effects WOT operation unless it's so old it's clogged up parts of the fuel system.
|
|
|
|
Post by rockacello on Oct 15, 2018 0:20:34 GMT -5
Seems like a simple thing to replace. I forgot to mention that when testing the TPS, the DMM would read open circuit between 3.5v and 4v when doing the sweep in a swift motion. When doing the sweep slowly, I didn't encounter any such open circuit reading.
|
|
|
|
Post by Stinger on Oct 15, 2018 2:44:27 GMT -5
That certainly doesn't sound right but I can't come up with any possible way for it to do that from a failure standpoint.
|
|
|
|
Post by rockacello on Oct 30, 2018 9:50:50 GMT -5
I replaced the TPS after spending a week to hunt down the right one. Unfortunately that had now effect. I was able to recreate the issue in the driveway and record it:
Next thing on my list is checking the fuel pressure as I've found the correct adapters to install the pressure transducer.
|
|
|
|
Post by Stinger on Oct 30, 2018 13:35:13 GMT -5
So the new TPS didn't fix the open circuit issue or it didn't fix the bogging/surging issue?
|
|
|
|
Post by rockacello on Oct 30, 2018 13:41:15 GMT -5
So the new TPS didn't fix the open circuit issue or it didn't fix the bogging/surging issue? It fixed the open circuit issue that I saw when measuring the voltage on the TPS while the car was KOEO. It did not fix the surging/bogging issue as shown in the video. It's an odd issue because if I slowly increase throttle to 2k rpm, it doesn't bog/surge/pulsate but if I stab the throttle to 2k rpm, it will do it. |
|
|
|
Post by Stinger on Oct 30, 2018 14:23:30 GMT -5
If the problem doesn't exist at higher RPM then fuel pump won't be the culprit.
|
|
|
|
Post by rockacello on Oct 31, 2018 1:49:07 GMT -5
That's what I've been thinking. I'm at a loss on what else it could be. Could it be an injector that is failing? It feels very similar to the start of an KOER test when the ECU pulses half of the cylinders...
|
|
|
|
Post by Stinger on Oct 31, 2018 9:35:23 GMT -5
Injectors don't "start" to fail, they either work or they are stuck open or stuck closed.
Without being able to see the sensor readings when it's happening compared to when it's not it's difficult to definitively say what it is. If I were to guess I'd say the problem is related to a lean condition and the VAM has the most control over fueling so maybe it's got a dead spot in the sweep of that sensor?
|
|
|
|
Post by rockacello on Nov 4, 2018 20:18:45 GMT -5
I checked the VAM thoroughly again and there are no dead spots when I sweep the sensor. The temp side read about 3.02v at 67*. I proceeded to clean it thoroughly with electric parts cleaner but no change. If anything, it idles and revs a bit smoother while the engine is cold. Though the bogging issue at 2000 rpm while the engine is warm remains. (It is easier to replicate as the engine gets warmer and warmer.)
Could this be a TFI issue at all? Also is it worth posting this issue at TurboFord?
|
|
|
|
Post by Stinger on Nov 4, 2018 20:39:37 GMT -5
TFI fails completely when hot if it's bad and you just lose spark.
You can certainly post it on TF if you want, it's possible someone's had the same problem or something.
|
|
|
|
Post by rockacello on Nov 12, 2018 12:50:14 GMT -5
FWIW, I was able to trace the issue to the EGR system. The EGR valve was oscillating on and off, I think I may have mixed up the vacuum lines at the junction fitting between the EGR solenoid and the signal line to the EGR valve. I'll have to mess with it come emissions time but for now I've just disconnected the EGR system and it appears to be running great.
|
|
