Limp mode - 29F1 on start. Injectors? Sensors? HPFP?

langsbr

Captain
Apr 5, 2017
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07 335i 6MT e90
I just replaced my water pump. Went for a test drive, and a hose popped off during the test. I pulled over, let the car cool and limped it home (less than a 1/4 mile) never saw the temp get above 250.
Today, I reinstall the hose, confirm it's tight and bleed the system.
On first start, I now get a 29F1 - DME:fuel pressure plausibility code, and 2 shadow codes:
2FCA - Fuel high pressure bei Freigabe dr Einspritzung
2FDA - Crankshaft sensor, signal: Missing
It will go to limp mode within 30 seconds after cranking, and giving those codes. I did a datalog at idle and the Low pressure sensor is above 70, but the rail pressure is anywhere from 70 - 130 psi unless I rev it some.
1. Any chance this is related to the overheating issue?
2. Does this look like a HPFP issue?
A friend suggested that possibly the overheating made an/some injector(s) go bad and stick open, preventing the HPFP from building pressure. Wasn't sure how feasible/common that was, but it definitely sounds plausible.
I know people say to replace the high and low fuel pressure sensors but I hate doing something like that for no reason.

Any thoughts?
 

langsbr

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Apr 5, 2017
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It lost about half I'd guess. There was some spilled on the driveway and in the garage once I got it home, so it wasn't empty, and it only took about a gallon to get it to full.

I don't see exactly how they would be related but it's disconcerting that it happened so soon after, so my thought is that it has to be related somehow, and the injector premise makes a lot of sense.
 

langsbr

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Apr 5, 2017
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Also, forgot to mention that when the car is running - there is a terrible fuel smell, like it's dumping fuel.
 

langsbr

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Apr 5, 2017
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Update: I did the injector test and found one that was just pouring fuel. This picture is only with the battery just connected, and the fuel pump priming.
1617552342113.png


I replaced it with a spare index 8 I had from a previous troubleshooting issue (ended up not being injector related so this should be fine) and no more leaks. I replaced all the decouplers and teflon seals and re-installed. Car cranks up fine, no codes, and rail pressure is good. There is a slight stumble, but I think that plug is fouled.

Headed to get a new spark plug and some oil (don't want to risk using the oil with fuel in it) and then we'll let her rip.
 
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seb.apprenti

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Nov 28, 2018
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is it possible to control the injectors without removing them?
I received the codes 29E1 and 29F1
# 6 cylinder spark plugs stay black
I swapped the spark plugs and the coils, but the 6 blackened
 

langsbr

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Apr 5, 2017
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is it possible to control the injectors without removing them?
I received the codes 29E1 and 29F1
# 6 cylinder spark plugs stay black
I swapped the spark plugs and the coils, but the 6 blackened

I'm not sure I follow what you mean by control the injectors? If you're getting those 2 codes, I would definitely think you have an injector issue. the 29F1 indicates the HPFP, but if the injector is flowing continuously, the HPFP can't build pressure - that was the case with my car. If you don't remove the injector, you won't know for sure if it's spraying when it isn't supposed to.

Removing the injectors is a very easy job as long as you have the rigth tool. The precision raceworks tool is fantastic - it's a remover/installer, as well as a teflon seal installer tool. If you do remove the injectors - ALWAYS replace the seals and decouplers when re-installing. I removed all 6, tested, and re-installed all in about an hour and I was going slow and taking my time. You might save yourself some time if you get a spare injector of the same index to have so you can replace it on the fly.
 
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langsbr

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Apr 5, 2017
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Removal and install also should be done with the right tool. You don't want to risk ovaling the injector hole.
 

seb.apprenti

Corporal
Nov 28, 2018
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I will follow your advice
I have three index7 injectors and three index9
I think I will in any case replace them with index12
I will do a quote at bmw and I look on google for the tool
 

langsbr

Captain
Apr 5, 2017
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BMW will be highway robbery for injectors. FCP Euro is the best choice if you want a lifetime warranty - but they are still 1400 bucks. I think OEMBimmerparts is the cheapest I've seen a set - at $800 but you don't get a lifetime warranty.

There are also some people here selling index 12s I think.
 
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seb.apprenti

Corporal
Nov 28, 2018
204
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reunion island
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I do not know
but for example ... the island of REUNION is a French island but 8100 miles from France
my family sometimes sends me parcels, i rarely get taxed but it happens
you have to declare its content and value (you have to cheat on the value)
I know someone at BMW, I hope he can give me a price
otherwise if someone you trust sells here, we can do business
 

BEASTN54

New Member
Dec 29, 2021
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I'm not sure I follow what you mean by control the injectors? If you're getting those 2 codes, I would definitely think you have an injector issue. the 29F1 indicates the HPFP, but if the injector is flowing continuously, the HPFP can't build pressure - that was the case with my car. If you don't remove the injector, you won't know for sure if it's spraying when it isn't supposed to.

Removing the injectors is a very easy job as long as you have the rigth tool. The precision raceworks tool is fantastic - it's a remover/installer, as well as a teflon seal installer tool. If you do remove the injectors - ALWAYS replace the seals and decouplers when re-installing. I removed all 6, tested, and re-installed all in about an hour and I was going slow and taking my time. You might save yourself some time if you get a spare injector of the same index to have so you can replace it on the fly.
YES I COULD AGREE .. BUT. i chanced the hpfp, lpf sensor no resolve i changed the 02 sensor after cats bank 2 problem solved. after weeks of looking for it. 29f1 no were to be seen ......and no more limp mode. and the hpfp is now pumping.