Edelbrock e-force hesitation:fuel pump?

[BLAKE]

So I just picked up this car, and it's great, but I do have a bit of a stumble at WOT. I haven't verified this, but I think it's reasonable to assume that I'm rolling with the stock fuel pump.

I've read something about using a GT500 unit, or a kit that wires in and tells the stock pump to quit being a bitch and step up. This is my first forced induction car so I'm a bit ignorant on the subject. Anyone have any thought on what could be causing this and what my best fix might be? In the mean time I'm going to try and keep my foot out of it so I don't lean this thing out too much.

Thanks in advance for any help you can throw my way.

 

[stkjock]

what tune is in the car?

 

[BLAKE]

what tune is in the car?

Hard to know for sure. Got it from a dealer that knows nothing about the car. My assumption is that it's the canned Edelbrock tune.

Do you think I'm going about it the wrong way wanting to throw parts at it? Maybe it's better to get it to a shop to diagnose and/or dyno tune?

If possible, I'd like to avoid throwing $600-800 at it for that, but it'd be cheaper than bending rods.

 

[stkjock]

I would first try to find out who owned the car to get more details.


I'm guessing it came without a handheld tuner?

you need to investigate more what's in the car before anyone will be able to give you good info.


did you search Eforce issues on the site? I have a vague recollection of there being a similar issue with a member or two.

 

[BLAKE]

I would first try to find out who owned the car to get more details.

Yeah I'm workin' on that.

I'm guessing it came without a handheld tuner?

That is correct.

you need to investigate more what's in the car before anyone will be able to give you good info.

I will do my best.

did you search Eforce issues on the site? I have a vague recollection of there being a similar issue with a member or two.

I did. Didn't find anything that seemed similar, but that could be my search skills or lack thereof.

Thanks a lot for your help!

 

[doogie]

Does the car have a CAI or the stock air box? If it has the stock air box, the tune is more than likely from Edelbrock.

The 2 issues I had with an early Edelbrock tune was stumbling when transitioning off idle (fixed with replacement TB) and it was running lean (updated tune).

What RPM does it stumble?

 

[weather man]

I wouldn't fool around with that stumble. Get it to a good shop who can get it on a dyno, or pick up a tuner and contact LITO on here.

What year car?

 

[skwerl]

Please don't throw parts at it without diagnosing the issue first. Odds are you won't fix it and may easily compound your issues. Then when (if) you get the original issue fixed you may not even know it.

Also, check for any vacuum leaks around the intake area. Basic maintenance items like cleaning the MAF won't hurt. Stumbling generally indicates lean so unmetered air entering the intake can cause a lean issue.

 

[BLAKE]

Really appreciate the feedback guys.

Stock air box, 2005 and I'm unsure of what RPM it's occurring. I only bumped into it once or twice and I'm doing my best to avoid a lean condition so I'm taking it easy.

I'm trying to track down the original owner without much luck so far.

So is that the consensus? Get it to a good shop and make it their problem? Hahah. I've always done my own hot rod work, but I'm out of my element with a blower.

 

[skwerl]

Unless you have a local tuner that specializes in Fords with power adders, you may be better off going with an email/remote tune. There are a couple Nationally known vendors who deal with the E-Force. I'm not sure but Brenspeed might be one? Doogie might have insight on that, or you could just use Lito.

Regardless, buying a handheld tuner device and datalogging for an email tuner or going with a dyno tune will both end up costing a few bucks. And you will have to buy a handheld for a dyno tune anyway. Check the classifieds for used SCT3 or SCT4 units.

 

[BLAKE]

Man, more fantastic info. Thanks again. I'm in Dallas/Fort Worth, so I have a lot of performance shop options. With that said, if anybody has any recommendations, I'm listening.

 

[doogie]

Really appreciate the feedback guys.

Stock air box, 2005 and I'm unsure of what RPM it's occurring. I only bumped into it once or twice and I'm doing my best to avoid a lean condition so I'm taking it easy.

Your comments about "bumping into it" makes me wonder if you are simply hitting the rev limiter which is usually set to around 6.5k??

Brenspeed is a great option as they have done a lot of work creating their Eforce tunes. I actually am running an emailed one from them right now after fighting emission issues after a local dyno tune. And it is running good enough that I never bothered following up with a dyno session.

 

[07 Boss]

is the traction control off? Losing traction will result in cutting the fuel to control power. If you romp on it and the tires spin the engine will bog out for a second or two.

 

[bcb06gt]

Does it to this "stumble" all the time? I would data log fuel pressure. My 2006 GT had a hit and miss "stumble" after my Saleen SC install. The 2005/2006 OEM fuel pump was the issue. I replaced it with a stock 2008 fuel pump. This was in 2009.

My fuel pressure would dip slightly to sometimes 10 psi. Car would literally "buck" like someone learning how to drive a manual transmission, but the buck would be while accelerating in the same gear.

Bottom line...don't throw parts on. I would start with a data log.

 

[BLAKE]

Your comments about "bumping into it" makes me wonder if you are simply hitting the rev limiter which is usually set to around 6.5k??

Brenspeed is a great option as they have done a lot of work creating their Eforce tunes. I actually am running an emailed one from them right now after fighting emission issues after a local dyno tune. And it is running good enough that I never bothered following up with a dyno session.

Not hitting the rev limiter. This probably happened around 4500 RPM. Good to know about the Brenspeed tune. I'll keep that in mind.

is the traction control off? Losing traction will result in cutting the fuel to control power. If you romp on it and the tires spin the engine will bog out for a second or two.

You know, that's a good point. I did not turn the traction control off, so this could be it, but it didn't feel like it was close to losing traction. Still, it's a possibility.

Does it to this "stumble" all the time? I would data log fuel pressure. My 2006 GT had a hit and miss "stumble" after my Saleen SC install. The 2005/2006 OEM fuel pump was the issue. I replaced it with a stock 2008 fuel pump. This was in 2009.

My fuel pressure would dip slightly to sometimes 10 psi. Car would literally "buck" like someone learning how to drive a manual transmission, but the buck would be while accelerating in the same gear.

Bottom line...don't throw parts on. I would start with a data log.

Noted. Thanks for that.

In other news, damn thing wouldn't start this morning. Tried to crank initially then I got a click. (solenoid?) It then displayed "engine fail safe mode". Thought the battery might be weak so I threw it on the charger and checked it after it was done. Full charge, so that ain't it.

It ran great last night and I was just cruising on the highway so I'm sure it's not hurt. Now I just have electrical or sensor gremlins to chase down I think. Sad face.

Anyone want to bet on a TPS?

 

[JimIII@JDM]

What kind of spark plugs are in the car, what is the gap set to? The GT500 fuel pump upgrade isn't all that bad of an install and highly recommended for your setup.

 

[BLAKE]

What kind of spark plugs are in the car, what is the gap set to? The GT500 fuel pump upgrade isn't all that bad of an install and highly recommended for your setup.

Good question. I was told NGK plugs but if I had to guess, the gap was not adjusted from what was in the box. This is from a small independent dealer that changed the oil and plugs, detailed it and flipped it.

 

[skwerl]

What kind of spark plugs are in the car, what is the gap set to? The GT500 fuel pump upgrade isn't all that bad of an install and highly recommended for your setup.

Sorry but I'm going to have to strongly disagree here. With a $35 wiring upgrade (reduces duty cycles by a real 10-15%) and a BAP the stock fuel pump is plenty strong for 500hp. At 425 you have tons of capacity to spare.

On the other hand if you plan on forging the engine and bumping it up a notch then the GT500 fuel pumps are great. I put them in my Bullitt when I went from 505hp to 600+.

 

[BLAKE]

Codes have been cleared and it started right up. Apparently it's a Throttle Body issue. I may have to see about getting a new one from Edelbrock.

 

[BruceH]

One thing that will cause a failsafe is if the predicted airflow doesn't match measured airflow by more than a 10% error. This can be the tb itself or it can be the tune. There are a whole lot of maps for airflow and they are fairly tricky to tune for unless you are using something that Ford or Ford Racing provided a value file for.

The Edelbrock supercharger was known for having tb issues when it first came out but afaik they figured it out and fixed everything. It's possible that the tune is causing the failsafe condition.

The best advice you can follow right now is to invest in an sct x3 or x4 and a quality tune. Do your research prior to selecting a tuner. Anyone can buy a dyno and sct license but it doesn't make them capable of tuning your car for driveability. I'd contact Manuel Pazo who goes by lito on this forum for tuning a 3v motor.

IMO your first order of business would be the tune. You may still need other things but you have to know the tune is correct first.