Repost: power loss issue

[nativetexan]

Any takers? Vile, Your thoughts are always appreciated sir.

[Irish_Alley]

one is a vent the other is return. would it be possible to check the signal to the pump while its doing the pressure drop. to see if the pump is getting a signal to stop pumping or its on the pump side thats causing the problem

[nativetexan]

Is there something that will do that? I thought it was just a constant 12v to the pump when the ignition is on...I will see if I can check volt while it is dropping. Thanks

[VileZambonie]

OK Captain obvious here but you do have ample fuel in the tank right?

After that, inspect for kinked/collapsed hoses. Is it dual tank?

The idle is too high even if it's cold. Check for vacuum leaks.

[nativetexan]

OK Captain obvious here but you do have ample fuel in the tank right?

After that, inspect for kinked/collapsed hoses. Is it dual tank?

The idle is too high even if it's cold. Check for vacuum leaks.

I'll check hoses, its a single tank. And I will revisit the vacuum leak theory. Is there a way to visualy see vacuum leaks? Soapy water?

[nativetexan]

So, I bought a set of caps for the open ports... I think that was the culprit. It is running a lot better. One thing I notice is that when I do a quick acceleration, it stays at 45mph until I let off the pedal and then it will speed up. Any ideas about that issue? I think it might be the OD on the 700R4 that I had rebuilt.

[nativetexan]

Well I swear, as soon as I say its fixed it slaps me in the face. Started it up today and its doing it again. Back to the drawing board...

[Irish_Alley]

did it get any better or still the same old problems as before?

[nativetexan]

Nope. Not really. I started it up and rev'd it a few times. Same dang thing as before.

[nativetexan]

No kinked hoses. any other ideas. I think I might take it in and let the pros take care of it. I just dont know what it is. What can cause a significant fuel pressure drop while gauged behind the fuel filter???

[rsandusky]

I think you should take the advice that was suggested earlier and replace the fuel pressure regulator. It sounds to me as if the spring in it is broken/weak and is unable to regulate the pressure when the vacuum decreases. It should maintain 13-15 psi regardless of throttle position or engine load. Have you put a vacuum guage on it while revving it and idling? Checked for collapsed or plugged exhaust? There are so many possibilities for why it is lacking power..If you're willing to do the leg work we can get to the bottom of it.

[nativetexan]

Checked the timing just now. Its good. I even revd it while adjusting the timing to different setpoints. Do you think it could be the regulator if the guage was behind the fuel filter? Thats probably a dumb question.

[VileZambonie]

Pinch the return line hose and find out.

[nativetexan]

Ok so I took a hint and removed the injector assembly from the TBI. I am going to replace the regulator but, The fuel pressure regulator housing is questionable as well. Check out the pics below. The inlet looks weird. Is that what it should look like? Also, the little lever on the side is not moving. Is it suppose to?

[Captkaos]

There isn't an inlet on the regulator, that is the sealed off plug for the pressure setting, the arm in where it was adjusted to, it doesn't move, there is a spring behind it.
I could have swore I posted my TBI rebuild thread here but apparently not...  I will add that to the list.  But if you drill out that end and then slot it you can make the pressure adjustable.

Anyway, what did the gasket look like that came off?