Fuel pressure reg issues
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Joined: Mar 2011
Posts: 9,175
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ok some data....its running rich at idle and ok at high rpm
its not a fuel pump
-does this have a flex fuel sensor...if yes, reset the sensor as if its askew it will effect trim.
-any aftermarket parts on this truck...list it all no matter how non-related it seems.
-since the issue is on both banks...look to thing that effect both banks...map, maf, iac
-does this vehicle use a iac or does it have drive by wire throttle control?
-if it uses iac what does the scan tool says the counts are at idle.
if it was both 02 sensors (rare that both would go bad at the same time)...02 data is ignored until closed loop operation so you wouldn't see an issue until it goes into closed loop
its not a fuel pump
-does this have a flex fuel sensor...if yes, reset the sensor as if its askew it will effect trim.
-any aftermarket parts on this truck...list it all no matter how non-related it seems.
-since the issue is on both banks...look to thing that effect both banks...map, maf, iac
-does this vehicle use a iac or does it have drive by wire throttle control?
-if it uses iac what does the scan tool says the counts are at idle.
if it was both 02 sensors (rare that both would go bad at the same time)...02 data is ignored until closed loop operation so you wouldn't see an issue until it goes into closed loop
Last edited by tech2; Nov 5, 2017 at 5:33 PM.
Thread Starter
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Joined: Nov 2017
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ok some data....its running rich at idle and ok at high rpm
its not a fuel pump
-does this have a flex fuel sensor...if yes, reset the sensor as if its askew it will effect trim.
-any aftermarket parts on this truck...list it all no matter how non-related it seems.
-since the issue is on both banks...look to thing that effect both banks...map, maf, iac
-does this vehicle use a iac or does it have drive by wire throttle control?
-if it uses iac what does the scan tool says the counts are at idle.
if it was both 02 sensors (rare that both would go bad at the same time)...02 data is ignored until closed loop operation so you wouldn't see an issue until it goes into closed loop
its not a fuel pump
-does this have a flex fuel sensor...if yes, reset the sensor as if its askew it will effect trim.
-any aftermarket parts on this truck...list it all no matter how non-related it seems.
-since the issue is on both banks...look to thing that effect both banks...map, maf, iac
-does this vehicle use a iac or does it have drive by wire throttle control?
-if it uses iac what does the scan tool says the counts are at idle.
if it was both 02 sensors (rare that both would go bad at the same time)...02 data is ignored until closed loop operation so you wouldn't see an issue until it goes into closed loop
So...
I don't think this has a flex fuel sensor, nothing mentioned in the service manual.
Aftermarket - I'd assume a lot at this point. I've only had it a short while, so not sure what all has been replaced. I think the MAF was replaced, the coil, beyond that I'm not sure. Its definitely been torn apart before! I've only replaced - clutch, brakes, ac pump and condenser, radiator, blower motor, thermostat, I think that's all that I've done.
Relooking at the mode6 (pasted below), 2 codes were for the MAF actually. Amazing how much I forget in 2 weeks, sorry. I cleaned the MAF but no change (didn't look dirty, appears normal as far as I can tell), prior to tearing apart. The other mode6 code was downstream O2 sensor, figured I'd just go ahead and replace them so that I can pass inspection, and figure if 1 is going the others may not be far behind (wan't optimistic it would change much but figured it wouldn't hurt).
The MAP is located under the plenum, so I think I may just replace this now to prevent potentially pulling this again soon. Sound logical?
This also has an IAC (still has a couple wire strands going to throttle body as well). I removed, cleaned, and reinstalled the IAC when I cleaned up the body. Had a decent amount of carbon build up. On my scan tool, I don't see anything around the IAC nor counts, not sure if mine isn't fancy enough or I'm missing it. Either way I have to get it put back together first to get this data anyway.
At this point I'd be inclined to replace the MAP, get running, run the OBD again and see how it looks. Replacing the MAF or IAC will be very easy in relation to what I've done so far. Does this sound like a decent plan to you, or ?
Probably at least a week until I get it running again. They sent me a different set of injectors than what I ordered with an elec adapter, and that adapter added too much height and not the plenum won't seat. Uhg.
Thanks yet again!!!
Super Moderator
Joined: Mar 2011
Posts: 9,175
Likes: 521
cleaning mafs sensor never works. cheap aftermarket air filters or oiled filters are a problem contaminating them. I only use factory air filters...aftermarket junk and performance filters do not meet filtering standards....usually the filter is clean and the maf screen is black with soot...the $10 people saved on the filter cost them a $200 maf.
