Any idears? Hard to start.

[pl4yboy]

I recently put LT's on my 08 and have noticed my truck is running very rich. I am in the process of getting a retune right now. The last couple of days my truck has turned over for 5-6 seconds before starting... and sometimes it doesn't even start then. It always starts on the second turn and I smell a lot of gas. There is a possibility that my plugs are semi fouled because I have noticed a decrease in mileage as well. I would assume that this would have started a week ago when I put my headers on if that was the issue. I'm thinking that this is tune or spark plug related. I thought it may have been a fuel pump at first (only 27k miles), but I tried priming it before starting and it actually made it worse. I have a feeling it is dumping too much fuel at start up. Any ideas?

[skeet]

personally wouldnt think the headers would be the culprit, not by dumping that much fuel, weeds out the fuel pump concidering youre getting to much fuel.. cant see a 08 model truck being that hard to start mine always starts on the first turn of the key, you running the stock injectors?

[pl4yboy]

Yes, stock injectors. I've had a 9.5 AFR at WOT for no telling how long. I just now got a wideband on it. With it dumping that much fuel at WOT, I can only imagine what it's doing at startup.

[skeet]

Yes, stock injectors. I've had a 9.5 AFR at WOT for no telling how long. I just now got a wideband on it. With it dumping that much fuel at WOT, I can only imagine what it's doing at startup.

ouch man!! thats filthy rich!! get it tuned!! 9.5 afr?

[pl4yboy]

Virgil tuned it... Someone else will be sending me a base tune in the next few days.

[RedHeartbeat]

Corvette post-cat 02 sensors usually help with correcting the AFR after installing long tubes.

[pl4yboy]

Greg, can you get them at parts stores or will I have to order them? Dealership? Summit?

[RedHeartbeat]

I buy them off Ebay but you can get them anywhere that sell 02 sensors. I always buy the Delphi sensors. They will have the wrong connectors on them, just splice them into your old connector with heat shrink type crimp connnectors.

[pl4yboy]

I'll wait until my tuner takes a look before I do anything. Expect a PM within the next week. I'll let you know how things go.

[RedHeartbeat]

when I had the tune in my truck with the 408 it was hard to start. I put the stock 4.8 tune in the truck after putting the factory 4.8 back in and it fires off first bump every time now. Weird.

Oh yeah, I even have the 42 lb lucas injectors on the 4.8L engine.