Is this on hot starts? if so it's likely the fuel is too hot in the rails. I used to rarely get this but only when its extremely hot and there is no cool down period like when pumping gas. Since I went with spacers this has not happened anymore
It’s usually on cold starts. I have not had the issue on hot starts. Once the car is hot the start is strong and normal. Once the car starts there’s zero issues at all. But it’s always a weak cold start sometimes dipping below 500rpm and rarely not strengthening and it just stops, requiring me to hit the push start again. Even more rare maybe 2 times. We’ve looked at the blowers bypass valve and it definitely opens delayed. Which does cause this Issue. Then there’s always the TB. Edelbrock has had TB issues in the past and that 103mm size is wacky.
Sounds like the bypass is not receiving enough vacuum at times to open it. Could be the cam Phasing but that's a shot in the dark. You would think with 12 compression that wouldn't happen.
Yeah. We shall see. It’s going into the shop for a few weeks I’m sure and they will run through a bunch of tests. Obviously replacing the bypass valve should be a major thing to look into. The shop I go to is really the best and well known. Also are engine builders so it’s in very good hands. I’m confident we will eventually figure it out. It’s been nothing but issues with this blower though. Edelbrock sent me the wrong fuel rails instead of for this car for a 2010 camaro. The pulley was misaligned by 1/100ths of an inch causing a terrible tensioner like chirp and needed to be fixed by my shop. And then this. Makes me wonder if maybe I should’ve just gotten a whipple and been like everyone else. It’s becoming quite annoying and seems like a legit QC issue with Edelbrock. Hoping everything works out but I’m beyond annoyed at this point.
On the S650 I will likely go turbo especially of top mount kits make more sense in the engine bay.i haven't had a whole lot of problems with my 2650 other than the stupid rails that could have been designed a whole lot better.
Excellent.
Yes, same problem with my Stage 2 . Spent a lot of time with Tony A on EB tech support reflashing and datalogging with no joy. Replaced the EB throttlebody and the MAF. Still no joy. I put my foot on the pedal when I start it. At least I don't have to pump the pedal like the four-barrel 351 Cleveland on my 70 Torino on every startup... LOL Good luck.
My issue occurs every maybe 15-30 cold starts. Otherwise it’s a weak start that shoots right back up. only occurs with cold starts. From what it seems is this is a bypass valve issue More than a TB issue. But lets see. I am in the process of having the bypass valve replaced. Lastly Edelbrock knows there’s an issue with the TB. Being the size. It’s very hard to tune for. 103mm is wacky. They are making a 108mm from what I’ve heard which should be much easier to tune for andwill probably fix many issues. you have a 17 and it’s a little different. That kit is known to have TB issues. Mine is an 18 and supposedly those issues with the TB are fixed. Who knows.
I don’t use an Edelbrock tune. Their tunes are known to be terrible. Im on a custom tune and have over 50 hours of revisions in it. I also don’t think The issue is tune related imho. It’s more mechanical. The fact that we have similar issues and different tunes proves that part I believe. And if you watch the bypass valve on start up it’s a delayed response. It does not open and close when it should and causes the stall. This issue combined with the awkward TB size I believe is what is creating the issue. It’s absolutely a vacuum issue. My shop installed an air restrictor in the bypass valve to control vacuum better and it did help a little along with freeing up about 2lbs of boost but still needs a little more. If I was to say how “perfect” my tune is it’s probably in the 90% but there’s still that issue here and there that drives me nuts. And my car definitely never stalls when left alone. Make sure the feature to automatically shut the car off after a certain amount of time isn’t on, on the actual mustang. And yes it’s crazy that Edelbrock hasn’t updated something to improve this. They are definitely aware of the issue. My car is going back to dial in the tune a little bit more from my shop. If any place can do it I know they can.
I believe when actually measured ithe inner diameter of the intake tube is closer to 107 or some weird number. It’s not actually 103mm. It’s slightly larger and is awkward in regards to tuning for that particular size.
