New TB and CAI - Stumbling / Small Backfire - HELP

[Ninety3Coupe]

I just bought a 70mm Accufab and a Black Out Series CAI from BBK. I put this on after installing a Edelbrock Performer two weeks before. I had driven the car with the Edelbrock only for about 2 weeks and all was perfect.

As soon as I pulled out of the driveway after putting on the TB and CAI the car would idle fine, but stumble (especially when cold, but all the time) around 2500-3500rpm under full throttle and then pull like a bat outta hell. It would still sound great while stumbling, but just not pull at all. :shrug:

I thought it was a vacuum leak so I looked high and low and did find one of those little hard plastic lines was busted (a white one- what the hell are those anyway?) and I patched that up with new hose. I took it out just now and it had what sounded like a small backfire this time, along with the stumbling. :fm:

I had disconnected the battery during install and took it for a 20 minute drive after the install to let it relearn anything it needed to.

Any ideas? Again, it drove perfect after the manifold, but the CAI and TB is what made it start to drive poorly. It's parked until I can get a hold of the issue. Thanks all!

 

[wheelhopper]

I don't see and adjustable fuel pressure regulator in your sig. Get one and try raising your fuel pressure a little.

I would also adjust your TPS.

 

[Ninety3Coupe]

Thanks for the idea WH. I have been thinking about the regulator, this may be the tipping point that makes me do it.

And it's time to find that article about the TPS again, I know I read it before on how to adjust it... Ya really think that could have something to do with it, huh?

 

[jamessims]

Ya I had the same issue if u order a regulator make sure u order the the pressure gauge for ur fuel line to adjust it perfectly it's cheap no worries...and it's a good quick reference for future upgrades proper fuel adjustment is key to survival so don't neglect to purchase the gauge...


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I am here: http://maps.google.com/maps?ll=29.044397,-95.452330

 

[Ninety3Coupe]

Great, thanks James. Do you have a recommendation? I have been striving to buy only the best with this car. I waited 21 years to get my high school dream car, I won't let a hundred bucks here and there prevent me from doing stuff right now!

Sure sounds like people think this is the issue... That would be great! With hyper pistons I am concerned I will pop one. No bueno! I pray this is the problem.

 

[wheelhopper]

Most any FPR you get will be good. I got mine and the gauge with the adaptor to fit from Late Model Restoration Supply. I just kept bumping the fuel pressure up until my hesitation issue went away.

 

[Ninety3Coupe]

Well, thanks yet again to you sir. I wound up buying this:

Aeromotive Adjustable Fuel Regulator
Aeromotive 13103 - Aeromotive Ford Fuel Pressure Regulators - Overview - SummitRacing.com

And I got this as well to assist with setting the number:

Crappy Summit Fuel Rail Pressure Gauge
Summit Racing SUM-800160 - Summit Racing® Chrome Plated Fuel Pressure Gauges - Overview - SummitRacing.com

I will get a fancy-smancy gauge for inside at some point, just want to save some cash in the meantime for other things.

Anyone think one way or the other about this purchase? I imagine it will fit without the need for some sort of adapter as it is meant for the car (I hope).

God willing this'll fix the issue. I miss driving it already!

 

[jamessims]

Looks good buddy


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I am here: http://maps.google.com/maps?ll=30.251605,-98.265581

 

[Knexo]

Wondering if this fixed your problem. I just ordered the same CIA, but got a 70mm BBK TB. I will also be replacing my cobra intake with a black TFS track heat intake. I also don't have a regulator, but the car has also been tuned. Please keep us upto date your problem getting fixed.

I'm up here in Mich with alot of salt on the roads, so the is sleeping for a couple more month before I can test my car.

Thanks,

 

[Ninety3Coupe]

UPS just delivered the regulator 10 minutes ago, are you watching? lol

I pray it does the trick. I have dropped a few grand in parts the past month, I am about out of Xmas Bonus money now... (read: Totally fricking out!)

I have to wait until this weekend most likely due to my work schedule. I will make sure and update this as soon as I know something.

 

[Knexo]

Thanks! I've got a bunch of money in mine this winter and hoping not to run into any surprises this spring.

 

[Ninety3Coupe]

Just got done installing the FPR and the gauge. Doesn't look like it fixed the issue completely however.

I set the pressure at a number of places with varied results. Right now it is at 55psi with the vacuum line attached. From what I've read that is way too high, right? It seems like it is a bit better but still not 100% right. I tried down to 35psi with the vacuum attached. 35 ran the worst by far. I finally set it at about 55psi with the vacuum attached and it has run the best so far, but still hesitates a little in the low end. It kinda feels like a car waiting to come on boost (obviously mine is N/A however).

Here is exactly what it does. If I roll into first gently and slowly and then early shift into 2nd and then floor it, it will start to go, then hesitate, and then when it hits close to 3000-4000 rpm it goes like a bat outta hell and all seems well.

It seems to idle a tiny bit smoother.

I checked and rechecked everything looking for a vacuum leak since I had to pull the TB again. I see everything connected and all is well. Everything was triple checked and torqued.

Any ideas guys? I am damn near outta the Xmas money now and I miss driving my car. I would love any and all input! My work car is a Prius for Christs sake, help!

 

[jamessims]

Make a video with ur phone an post it on tube and send us a link so we can try to help u troubleshoot...


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I am here: http://maps.google.com/maps?ll=29.036618,-95.426710

 

[wheelhopper]

Looking at your sig, I am guessing you have the stock fuel pump. You should probably get a larger pump, and did you adjust the TPS?

 

[Ninety3Coupe]

I began by checking the TPS, it was a solid 1.00. Seemed close enough to me.

I do in fact have to stock fuel pump and was about to purchase a new one. I will either SC the car or do heads and a cam next, so I want a pump I can grow in to. I was thinking a Walbro 225lph (part number GSS 340). Anyone have a suggestion or know a better pump I should be buying?

Does this sound like the next logical step to anyone else? Since the condition improved with the additional pressure I figure the volume is the issue. IIRC when pressure goes up, volume goes down with all else being constant. If I increase the pumps ability to provide volume, then I can back down the pressure to a more normal level. This should give more volume at a higher pressure.

Or did I space out in science class and I am completely wrong?

See video. IMG_2091.MOV - YouTube

The video sucks and of course it wouldn't really do it while the camera was going. As soon as I turned the camera off it'd do it, I turn it back on and it would act nicely.

Sheesh.

In the video I have it floored from the moment I shift to second gear. Notice the lag and it not "getting down and going" until after 3500 or so. This is not an extreme case like it does normally, but an idea of what's going on. And I hate the whistle from the new TB btw!

Thanks guys!

 

[wheelhopper]

The way I see it is that you are not getting enough fuel. If you had a larger flowing fuel pump then the added pressure would take care of your problem. However, your stock old pump is not sending enough fuel to the injectors regardless of the increased pressure.

I have a 190lph fuel pump, I am staying NA, and so far have been very happy. I would say get a 255lph, that is the largest stock style in tank pump that I have seen. And see if that cures your issues. My guess is that it will. If you wanted to leave the pressure down and fix the problem you would have to install larger injectors.

 

[Ninety3Coupe]

I agree. I got this: eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

The place is right down the street and seems like a good place. The install video on BBK's site is EXCELLENT and seems like a pretty easy swap to do (or a lot easier than I would have thought anyway).

I just played with the pressure again and it really confirmed fuel as the issue for me. I unplugged the vacuum, set (lowered) it at 42 and then attached the vacuum. The car idled VERY poorly and then when I tried to drive it the problem was 100X worse. The car wouldn't move out of it's own way, but had the same symptoms as before - just a lot worse.

So fuel does seem to be the culprit. Based on the calculations I have seen, the injectors should be more than adequate for my HP levels (even at the optimistic 250+ Flywheel HP range which I figure I am under). Once I replace the pump I figure that should cover my in the fuel department for a while...

Updates when I install. Any and all input still welcome! Thanks guys!

 

[Ninety3Coupe]

Ok guys, still having an issue after installing a Walbro 255 pump. FP is set to 45 with vacuum disconnected.

Another wrinkle came back as well and it may be related. I have put thousands of miles on the car and it gets fresh gas constantly, but I smell bad gas when idling or driving slowly for any amount of time once warm. Last night when I stopped at 7-11 to buy beer for my friend to help with the pump (and after sitting in stop and go traffic) the car would not start in the parking lot.

I had been smelling the bad gas smell on the drive just prior, and this had happened once before (1 month ago) with a fellow SVTP member in the car. We were cruising a commercial area very slowly looking for a business - almost idling for about 5 minutes and it smelled like bad gas and wouldn't start after we shut it down to go inside the place. 20 minutes later it started right up, fine. Hasn't happened again until last night.

Just for fun I opened the gas cap last night during the no-start issue and heard no noise - vacuum or otherwise, if that matters.

Once I got going again last night (another 20 minute wait fixed it) I dropped the tank and looked very carefully inside. The gas tank looks perfect, clean, clear, nice and pretty. Smells fine like normal gas inside too. The gas in the tank is not bad.

I have a new vacuum line running from under the manifold to the charcoal canister, which I have read can be an issue. Still smells like bad gas, still stumbles when stomping on it with low rpm's then goes like hell after 4000-ish... I'm at a loss.

On Feb 11th I have a dyno day and the ricers I work with are talking smack. This is obviously unacceptable and I must destroy them. We gotta get this fixed by then guys!

 

[wheelhopper]

What is your timing set at. If your timing is advanced real far, it can be hard to restart a hot motored 5.0, even if your not geting detonation. I have my timing set at 15 degrees advanced and after I come off track and turn the car off, I can't restart it for about 20 minutes, until it cools. Try setting the timing at 12 degrees advanced.

If you are still running the 19lb injectors, try increasing your fuel pressure to near 50psi.

 

[Ninety3Coupe]

Timing is set to 12 degrees. I will try bumping pressure, but I would have thought 45 would be enough. I do still have my 19# injectors.

Any thoughts on the bad gas smell anyone? I ma not trying to bombard this one post with 50 questions, but they may be related so I mention it. I keep reading about the charcoal canister and the rotten lines (my lines appear very clean and crack free), the valve associated with it, etc. The problem is the dozens of threads I see with kinda similar problems always just end without anyone saying what the solution was.

People have thrown a million parts at these symptoms and no says what the answer is.

Thanks again WheelHopper, and others, please read my last posting on here for more info on the latest issues.