Engine troubles - 3.0L SC V6 - possible multiple-injector failure

[scott schmerge]

Scott,

Maybe HPFP? I know there are two. I just don't remember if the each feed a bank, or if the work in series to push fuel. If the former, maybe a faulty HPFP would trigger misfire conditions by whatever logic is programmed into the computer.

good thought. But would the HPFP cause ignition issue with fuel flooding the cats and coming out tailpipe? Feel like that would be a result of lost spark or stuck open injector. Definitely please correct me if I’m wrong.

 

[Michael Gain]

good thought. But would the HPFP cause ignition issue with fuel flooding the cats and coming out tailpipe? Feel like that would be a result of lost spark or stuck open injector. Definitely please correct me if I’m wrong.

That I do not know. For the sake of discussion, I guess if some fault actually increased fuel pressure, it could overrun the injectors' ability to meter fuel, thereby keeping them open. To be honest, I have no idea how strong the mechanism is that stops the flow of fuel every pulse, but I picture increased pressure preventing the "gate" from closing.

Likewise, it could just be the injectors are past their time. I would think that they would not all go at the same time though.. either way, I pray that you're able to figure it out!

 

[Michael Gain]

Too much fuel could also prevent spark by gas fouling the plugs. I saw in the other thread that you were going to pull the spark plugs. Their condition may help figure out if it is spark or fuel related, but will not help narrow down which fuel/ ignition component is faulty.

 

[Michael Gain]

Sorry, I'm a slow thinker lately... also, might want to check your oil. If there is enough gas in the cylinder to exit through the exhaust valves, and out the tail pipe, there is enough to blow-by the piston rings into the crankcase..

 

[scott schmerge]

Too much fuel could also prevent spark by gas fouling the plugs. I saw in the other thread that you were going to pull the spark plugs. Their condition may help figure out if it is spark or fuel related, but will not help narrow down which fuel/ ignition component is faulty.

Yes. Agreed. Had already anticipated that I’ll give it an oil change. I’m gonna go ahead and do injectors and plugs and see where it gets me. Will report back.

good point on plugs revealing if it’s bad fuel. Had not thought of that.

 

[Fields Carlisle]

Never heard of Sheetz. They likely buy their fuel off the commodity market from several suppliers. While they are all 93 octane, the quality varies greatly. I have also heard, whether right or wrong, that the bottom of the supplier tank is sold at discount.

We’re in the fuel industry. All of the raw petroleum is transported to terminals from one central pipeline (for example, the Colonial Pipeline). Only at the terminal is the fuel then separated and a tiny fractional amount of additives put into the fuel. Sheetz is one of the larger East Coast gas chains. Their fuel comes out of the fuel terminal like everyone else’s. We used to own a fuel terminal.

 

[Fields Carlisle]

sorry, 2010 LR4 HSE LUX. I already have the passenger side pulled apart up to the fuel rail. It’s loosened and ready to come out while I wait for injectors to arrive (tomorrow). Slide hammer tool comes today. It’s not altogether that bad in the non supercharged 5.0. Also have plugs on order to knock that out at same time as they are also originals and should have been replaced by PO (I bought at 115k). The ignition issue could also be plug or fuel related (but I always run 93 from reputable stations). Since injectors and plugs are due, figured I’d start there.

If I had the 5.0L I would have done it myself, but I didn’t want to take the supercharger off myself. I really wish I would have had them do spark plugs and the supercharger isolator while they were working on it.

 

[scott schmerge]

If I had the 5.0L I would have done it myself, but I didn’t want to take the supercharger off myself. I really wish I would have had them do spark plugs and the supercharger isolator while they were working on it.

i know nothing about the SC engine, but I’m curious if you’d need to remove the SC to get to the plugs and injectors. I was able to do my injectors and plugs with my intake manifold still in position. I’d think the supercharger could stay in place as well.

All I had to remove were wire looms, coils, and fuel rails to get the job done.