Ok I can't seem to figure out what the noise my engine makes. I just installed my edge comp box yesterday (Not wire tapped) to make sure everything was going to work properly when I do decide to tap the pump. Now when the engine is down in the lower rpms and i stab the throttle I get a slight loss of power, and a terrible "grunting" sound. To me it sounds like the timing is WAY off from what is should be, But as soon as I build a couple pounds of boost the horrible noise goes away and the power comes on instantly. I have no codes, smarty is set to stock, FP is 15wot 19idling. IP is 2 1/2 months old.  I thought I had read somewhere that if the MAP sensor voltage is way low it will change the timing, but I could be wrong. Any  thoughts?? Sorry for the paragraph I'm just baffled Thanks in advance

If that was not an electronic pump...meaning any of the old mechanical engines.

I would say you have a broken /damaged injector and actual combustion pressure is going back to the tank.

I am not sure its possible with this style pump.

Its not good either way.

With your white exhaust and now this situation, I would be thinking about pulling the injectors.

Nothing but your time and a few O-rings at best. At worst you need injectors.

Regards Chris  

The exhaust clears up if I drive it a little ways and it warms up. There is a "cough" sometimes when it starts, but never missing while it runs. Either way it does clear up, which makes me lean against a broken injector, but I should probably pull them and have them tested anyways ( 174, 055 miles ). I have spring break next week and I will be home to pull some things apart... As for now this is my dd so it can't sit. Keep the ideas coming guys I really appreciate your time!

maybe put a clear line some where in your return line so you can look at it.

Be carefull of a nasty splash.

Chris

I have heard of a plugged vent causing a vacuum on the tank, but nothing that would cause pressure like that. I dont think there is supposed to be pressure in it though. Maybe try leaving the cap loose and driving around. See if there is a difference.

My vote from descriptions is an injector issue, just dumb luck it coincided with the EZ install, nothing I know of an EZ can do to cause this issue.

kinda  wonder if  he  had   an  injector  that  was  *almost*  cooked off,  and  adding the  EZ   (and  playing around)  finished it off??

Leaving the cap loose seems to have fixed the issue, but I won't know for sure until tomorrow. As to how the pressure built up I think it was the drastic change in temperature. We went from below freezing to the 60's. When I have the cap off and the engine running there isn't any "blow by" coming out of the hole so I believe my injectors are OK.   Thank you guys for your input! 

so did the white smoke go away with the cap off?

Thanks for the suggestions guys. I just pulled the cap off my fuel tank for the hell of it and there was enough pressure to blow it out of my hand... Like a ridiculous amount of pressure. Could that be causing anything??

 

 

Did it "blow" out of your hand……….or did it get "sucked" out of your hand???  Serious question.

Did it "blow" out of your hand……….or did it get "sucked" out of your hand???  Serious question.

 

Blew it out of my hand as in pressure inside the tank not a vacuum 

 

so did the white smoke go away with the cap off?

I will report back in a couple hours after I go start it......

With the cap left loose it starts with zero problems! No white smoke even at 30deg. After starting I tightened down the fuel cap and drove to school. I had pressure built up in the tank by the time I got to school (6miles). The outside temp was increasing pretty quickly, but I didn't think quick enough to cause pressure that fast?? Any thoughts as to why I get pressure in the tank built up so quickly?

Bad copper sealing washer or injector o ring letting combustion gas in the return rail maybe? Just thinking out loud here.

I concur.

 

Ed

Yep. Something funky with the injectors letting compression back to the tank via the return line. I have also heard that a cracked head could do the same thing. Worst case scenario though and unlikely.

Thanks for the tips guys. I will be looking into it this next week. Does anyone know how the tank is supposed to vent, and what part I would need to at least fix my venting problem?

I think the fuel cap should do some of the venting. There is also supposed to be a vent on the top of the tank somewhere. They are common to plug up with dirt and what not. I think a lot of people actually make their own vents because of the plugging up issues with the stock one. I am not sure about that stuff though as I have not yet had a vent issue with my tank.

It would be a good thing to fix the vent on the tank, but you really need to fix the main problem.

I think the fuel cap should do some of the venting. There is also supposed to be a vent on the top of the tank somewhere. They are common to plug up with dirt and what not. I think a lot of people actually make their own vents because of the plugging up issues with the stock one. I am not sure about that stuff though as I have not yet had a vent issue with my tank.

 

Tanks vents are designed to vent the vacuum off but not pressure. This is a safety issue for emergency responders like fire dept to have a fuel tank gain pressure from heat or fire and have it start venting liquid fuel like at a vehicle accident. All fuel tanks should hold pressure to a point just a safety design.

So should it vent after a certain psi, or should it hold all pressure no matter what?

The vent on the fuel cap is like a check valve. It only relieves vacuum, not vice versa. If your building pressure, it will not be relieved. This is a safety feature built into the fuel cap. If the vehicle rolls-over, the valve is shut preventing fuel from leaking out of the tank.

 

Look for the vent port on the tank:

 

http://i642.photobucket.com/albums/uu142/illflem/TankTop.jpg

 

Make sure this vent is not plugged with debris.

Is there an easy way to test if air or compression is being pumped into the tank? Will pulling the return life off while the engine is running and letting it pour into a bucket show if there is any aeration from an injector seal? Right now I have to drive around with my fuel cap loose so that I don't build tons of pressure inside the tank. Thanks again for all the help!