check engine light cut out in boost

[John DeCampli]

my has had a check engine light on since i bought it i replaced the turbo and a few little things this is the last thing wrong and i cannot figure it out the light is for (fuel pressure up solenoid) code-p1105 my car cuts out in middle of boost like stutters im guessing these two are linked and i already replaced what i believed to be the problem

this part was just replaced
2CarPros Search Results for automo 6886 FPS 1

 

[Chicken Patty]

Did you reset the ECU after you put the new solenoid in?

Also, check the wiring and make sure the wiring is good. Any problem to the wiring could cause the code to be thrown and you can replace as many FPS's as you like, but it won't fix it. Use some electrical cleaner and clean the connector.

Also, what spark plugs are you running and what are they gapped to? Seen a case where spark blowout was causing the ECU to think the FPS was bad for some reason. Guy replaced plugs, gapped them properly and reset the ECU. Code never came back on. Just something to ponder about.

 

[Chopstick88]

Maybe you aren't getting enough fuel pressure? What psi are you running?

 

[John DeCampli]

i considered this but how do i turn it up i noticed the solenoid turns does this adjust the pressure? and i am not sure what i am running

 

[Chicken Patty]

i considered this but how do i turn it up i noticed the solenoid turns does this adjust the pressure? and i am not sure what i am running

I never really ran my car with solenoids since with DSM Link you can delete them, and I don't remember, but I don't think there is anything you can do to the solenoid to raise fuel pressure.

You might have a faulty factory Fuel Pressure Regulator if you are indeed having low fuel pressure.

 

[4g63t]

It can not be adjusted. It only has a vac line to it. If I rememer right thease only are in use for the egr system.

 

[rlacasse1]

Did you replace it with a stock turbo? How much boost are you running? And have you done a BLT?

 

[John DeCampli]

i replaced it with another new stock one that only hits 14 lbs and whats that?

 

[Boost_freak_87]

Replace the stock fpr. I'm sure that will fix your problem.

 

[Diamond Star Werks]

i replaced it with another new stock one that only hits 14 lbs and whats that?

BLT is a boost leak test. Check to make sure all your clamps on the intercooler couplers are tight and the couples are on correctly and are not deteriated or cracked anywhere. If you want you can buy a boost leak tester. visit this address to get one and to learn about how to use them. TURBO BOOST LEAK TESTERS - Kits For All Turbo Charged Vehicles

 

[JusMX141]

Boost leak somewhere, possible fuel pressure issue linked to the solenoid code.

I'd bypass the solenoid for now- run a line straight from the intake manifold to the fuel pressure regulator, see if the problem goes away.

 

[John DeCampli]

thank you all very much i removed the plugs and they where not even gaped they where like triple what they should be and my problem seems to be fixed too much snow to tell for sure but i have no more code for the sensor and it seems to not be cutting out

 

[NHerron]

Does anyone know why the spark plug gap would cause that code to pop up?

 

[Chicken Patty]

Well naturally when you blow out spark (what was happening in his case) the misfires will cause the o2 reading to go leaner than usual because you are not burning the fuel due to the spark going out and misfiring. So I'm assuming that the ECU thinks that those lean spots from the misfires is lack of Fuel Pressure or something. Only thing I can think off.

 

[NHerron]

Do you mean rich? Because if I understand correctly, that would make sense being rich, and the ECU thinks the FPS is restricting the intake manifold pressure line to the regulator right?

Now that I remember, air is an insulator so as he hit boost, he started getting a crappier spark then finally, no spark at all.

 

[Lofty]

Check your battery terminals too. I've had my car jutter during pulls, it was loosing battery connection...

 

[John DeCampli]

Yeah I had a computer with my tune on my talon I sold and when a terminal got loose my while system would shut off and
reboot for a second

 

[Diamond Star Werks]

it could be throwing the temp sensor code due to the fact that with the big gap it not burning fuel properly and then finally as said it blows out the spark and since its running rich maybe the ecu thought the sensor staying cold. though it doesn't seem very solid that that would be why.

 

[knochgoon24]

Do you mean rich? Because if I understand correctly, that would make sense being rich, and the ECU thinks the FPS is restricting the intake manifold pressure line to the regulator right?

Now that I remember, air is an insulator so as he hit boost, he started getting a crappier spark then finally, no spark at all.

It actually reads leaner, not rich, due to a misfire.

The o2 sensor is measuring the amount of oxygen left in the air, and from that, inferring what the air to fuel ratio was. If it misfired and it didn't burn, all that fresh air is still left, giving you a lean reading.

Under boost, the car doesn't do much to adjust fueling like it would in closed loop. It only adds fuel when it detects knock. It does this by increasing the injector pulse width, not by changing the fuel pressure with the FPS. The FPS blocking flow would cause the car to run lean under boost and rich under vacuum.

 

[NHerron]

So what about lack of ground causing the car to have little fits? I have only two grounds from my battery, one to the starter bolt and one to the firewall. The firewall one broke and I didn't have another eyelet to put on so i cleaned it down to the metal behind where it went on and just tightened it down over the wire. Sometimes when I'm driving I can feel it hold back like jitter at times then pick back up. Sometimes on start-up the lights and gauge lights flicker, but I never have any charging problems and battery terminals are on good. Do I need to add more grounds?

Yeah I would say to hook up your ground again. I had the same exact issue. When I got my dsm, the lights were acting funny and that's when I found the cable wrapped with electrical tape. Underneath tape, the copper strands were all coming out of the eyelet and was not making a connection. I went to the junkyard and just got the new cable that attaches to the firewall. I also picked up a few extra grounding wires so I can replace any wires that break or just look too old.

It actually reads leaner, not rich, due to a misfire.

The o2 sensor is measuring the amount of oxygen left in the air, and from that, inferring what the air to fuel ratio was. If it misfired and it didn't burn, all that fresh air is still left, giving you a lean reading.

Thanks for clearing that up, I didn't realize that.