mylilgt

Has anyone else had their car backfire through the exhaust at WOT? I installed a tune from Alternative Automotive and the car ran great with no problems for a month then one night filled the car up and got this missfire. I took the car in and they stress tested the coil packs and replaced cyl 6&7 then returned the car to me. Took it to work and on the way home tried it out to see if the problem was fixed. At WOT the cars power fell off and the miss returned by the time I got to the house the CEL was blinking so I went in and hooked up the preditor to get the code. The damn thing didn't show a code! so I left the tuner plugged in and took the car for a short but hard drive and finally got the code for missfire on cyl 8. I returned the car to the dealership and got all the remaining coil packs replaced along with the plugs. I then tried this again going to work and the problem returned so back to the dealership. One of the techs is super sharp so I took him for a drive and what we came up with is four possibilites 1) lean condition caused by a fuel injector sticking, 2) a weak valve spring, 3) the butter fly plate between the manifold/head has one or more blades malfunctioning, or 4) worst case a bad head. I've removed the tune and replaced the CAI with the factory to build up a data base because they are having a engineer come check the car in two weeks. Without looking at the car he told the tech he believed that he knew what the culprit was but would know for sure when he got there he strongly thinks it is one of the blades in the plate between head/manifold. So has anyone else had a similar problem?

mylilgt

Just needed to add this it wasn't the tune Alternative checked the program out and its fine so I wanted to remove any possible thought it was the tune . The guys at Alternative have treated me very well and their tune was dead on for the car so I'm looking forward to getting this problem fixed so I can get it back in the car and enjoy myself again.

Daniel60

I have gotten check engine light for a misfire when I got my car the first week and that was before I installed the CAI. They reset the check engine light and asked me if it ran bad and I said no. Then a few weeks ago I had it happen again. They checked it and sent me on the way when I went down the interstate ***** to the wall and was down shifting and seen the check engine light blink and the engine went into a limp mode. This means that the engine operates on like several cylinders. Anyway I went to the speed shop where I had my pullys installed weeks earlier thinking it was something to do with that and they said I need more octane then the normal 87. So I ran the 93 octane and kept the tune on 87 and noticed a big difference and haven't suffered any more check engine lights. By the way the ford place received the check engine lights but the coils were always fine. But if this means anything when I first got my car I noticed it ping on 87 octane though thats what they recommended. My car doesn't ping on the 93 octane and runs better. Also know that Brenspeed has worked with me on this offering to take some timing out of my 87 octane tune and when I mention to them it pinged when I rode her hard before I got the tune and CAI they recommended against it. Anyway try the higher octane and see what happens. Today I switched to 89 octane tune with the hightest gas and I'm going to see how she runs. One thing I will tell you I'm not running 87 octane no more because the pinging can cause the car to do a misfire. The local speed shop told me that when you buy the 87 octane with these CAI and tunes that it needs more octane and I think he is right. Also don't put any cheap gas in your car use major brands like Sunco or hess, not those fly by night gases that you have no idea what it is. If someone reads this and thinks I'm full of *hit please let me know.