Lightning Rodder banner
1 - 8 of 8 Posts

·
Registered
Joined
·
202 Posts
Discussion Starter · #1 ·
The first 800 miles I drove my lightning, it ran fine. Stock with K&N fipk and a Diablo chip. Then it suddenly started throwing a cyl 6 misfire code along with P0172/175 rich codes.

I replaced the plugs with TR-6s, and the coil on cyl 6. I also cleaned the MAF. It ran better for about 100 miles, then threw the rich codes again.

I removed the Diablo chip, unhooked the battery for an hour, then tried it again. It ran correctly again for a couple days then the rich codes came back.

I threw a wideband in and it will peg to 9.0 AFR under WOT. This is with a stock MAF, and no chip.

I suspected the MAF may have been bad, so I installed a BA2600 that I had on the shelf, along with SCTs Xcal3 and 93 octane tune with the transfer function for a BA2600 loaded into it. I took the truck out and it ran like never before. It pulled great through the gears and definetly had more power.

However, now 2 weeks later and about 100 miles of driving, the rich codes are back and its running like crap. You can obviously feel that its rich.

I am loosing my mind with this thing. I know it has to be something simple, but I have no idea what to check next. I don't see how it could run great, then a few miles later, it runs like crap. Any ideas before I drop a match in the tank?
 

·
Divergent
Joined
·
13,541 Posts
before you drop a match in the tank feel free to send me the keys. Ill pm you my address. Ill give you a grand for your trouble and we can call it a day. :bigtu

but in all seriousness...good luck finding the culprit. Hopefully someone will chime in with a quick solution for ya.
 

·
Premium Member
Joined
·
14,841 Posts
You need to get it figured before you totally ruin your cylinders with fuel wash down...When you log the truck what kind of readings are you seeing on your o2 sensors?...Is the idle of the truck erratic like there could be a vacuum leak?...Have you checked the PCV lines at the back of the the lower intake?
 

·
Senior Member
Joined
·
333 Posts
Just need to ask a few more question:
1. What fuel pumps/fuel system changes have you made...ever?
2. What tune...stock or professional and when was it tuned...conditions... temp/pa?

Here are a few suggestions but keep in mind that without the above questions answered its a shot in the dark. If you have upgraded your pumps to say 255's then there could be a problem with them over running the stock fuel pressure regulator. If you installed and aftermarket fuel system and didn't change the tune you could be tuned for a much lower fuel pressure than what you have now. If you had a very conservative tune done in say 30 degree weather and now its 100 degrees that could be a problem too. Mine runs rich in the summer. Simply put....in order to be rich....your tune is either pumpin too much gas or not metering enough air. Check your TPS resistance...there is a how too here on the forum. I am sure this evening you will get plenty more suggestions from other members.... So don't take mine to heart...
 

·
Fat Bastad
Joined
·
2,756 Posts
From how you describe it I suspect that something is fouling your mass air sensor and your MAF counts are off.

I also cleaned the MAF. It ran better for about 100 miles

I suspected the MAF may have been bad, so I installed a BA2600 that I had on the shelf, along with SCTs Xcal3 and 93 octane tune with the transfer function for a BA2600 loaded into it. I took the truck out and it ran like never before.

However, now 2 weeks later and about 100 miles of driving, the rich codes are back and its running like crap.

It makes sense that it would take a bit longer for the brand new sensor to become fouled.

Clean your MAF once again and see if it doesn't temporarily clear things up. Or better yet change your air filter with one that isn't oil soaked at the same time you clean your MAF. The K&N filters use oil to help remove dirt from the air. That oil can foul your sensor. I suspect that's what's going on.


Roach
 

·
Divergent
Joined
·
13,541 Posts
From how you describe it I suspect that something is fouling your mass air sensor and your MAF counts are off.

Or better yet change your air filter with one that isn't oil soaked at the same time you clean your MAF. The K&N filters use oil to help remove dirt from the air. That oil can foul your sensor. I suspect that's what's going on.


Roach
Sure enough. Thats what messed mine up...it threw different codes so I didnt connect the dots to what your experiencing. Its probably too much oil on the K&N.

But wouldn't the oil get all over the MAF on the 1st WOT...hes talking a couple hundred miles before it starts acting up?
 

·
Registered
Joined
·
202 Posts
Discussion Starter · #7 ·
You need to get it figured before you totally ruin your cylinders with fuel wash down...When you log the truck what kind of readings are you seeing on your o2 sensors?...Is the idle of the truck erratic like there could be a vacuum leak?...Have you checked the PCV lines at the back of the the lower intake?
Washing the cylinders has me worried. Especially since I KNOW its going less than 9.0 at WOT. I lifted the ringlands on my turbo 4.6 mustang when fuel pressure spiked and went rich.

Idle is fine, and I have checked for leaks using propane as well as visually inspecting all of the lines.

Just need to ask a few more question:
1. What fuel pumps/fuel system changes have you made...ever?
2. What tune...stock or professional and when was it tuned...conditions... temp/pa?

Here are a few suggestions but keep in mind that without the above questions answered its a shot in the dark. If you have upgraded your pumps to say 255's then there could be a problem with them over running the stock fuel pressure regulator. If you installed and aftermarket fuel system and didn't change the tune you could be tuned for a much lower fuel pressure than what you have now. If you had a very conservative tune done in say 30 degree weather and now its 100 degrees that could be a problem too. Mine runs rich in the summer. Simply put....in order to be rich....your tune is either pumpin too much gas or not metering enough air. Check your TPS resistance...there is a how too here on the forum. I am sure this evening you will get plenty more suggestions from other members.... So don't take mine to heart...
The truck is stock, fuel system is stock. That is why its so wierd, it does it with everything stock. The Diablo chip was their canned tune, and with the stock MAF and SCT canned tune, it went rich as well. Then with the BA2600 and transfer overlayed into SCTs tune, it still did it.

From how you describe it I suspect that something is fouling your mass air sensor and your MAF counts are off.

I also cleaned the MAF. It ran better for about 100 miles

I suspected the MAF may have been bad, so I installed a BA2600 that I had on the shelf, along with SCTs Xcal3 and 93 octane tune with the transfer function for a BA2600 loaded into it. I took the truck out and it ran like never before.

However, now 2 weeks later and about 100 miles of driving, the rich codes are back and its running like crap.

It makes sense that it would take a bit longer for the brand new sensor to become fouled.

Clean your MAF once again and see if it doesn't temporarily clear things up. Or better yet change your air filter with one that isn't oil soaked at the same time you clean your MAF. The K&N filters use oil to help remove dirt from the air. That oil can foul your sensor. I suspect that's what's going on.


Roach
I have saw issues with K&N filters in the past and know all too well about the oil. This one has not been cleaned recently (still clean enough to flow) and has no excess oil on it.
 

·
Fat Bastad
Joined
·
2,756 Posts
Sure enough. Thats what messed mine up...it threw different codes so I didnt connect the dots to what your experiencing. Its probably too much oil on the K&N.

But wouldn't the oil get all over the MAF on the 1st WOT...hes talking a couple hundred miles before it starts acting up?
It's hard to say really. It might live through a number of WOT blasts before acting up. So far as a couple of hundred miles he indicated that was after he put the new one on which it would make sense that a new one would take a bit longer to accumulate enough crud on it to begin causing problems.

To the OP....Try a clean filter.

I still say try it without the K&N filter on it and see if that helps. You've indicated that the truck ran good after each time you cleaned the mass air sensor. The question is why does it keep requiring having to be cleaned in order for the truck to run right. You've cleaned it twice now and it improved. Clean it a third time and see if it doesn't improve. If it does then your goal is to figure out why it keeps getting fouled to begin with....I highly suspect it's the K&N. Maybe not but if you don't wish to rule that out then I am at a loss of where to go on this...:smt102
Have you cleaned your IAT lately?

Roach
 
1 - 8 of 8 Posts
Top