Text only | Text with Images

Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: Carl on May 08, 2011, 02:49:31 PM

Title: Hesitation
Post by: Carl on May 08, 2011, 02:49:31 PM
I just installed a Walbro 255 on my Tbird because my stock pump was pretty much dead.  I am running 18 psi on the stock turbo and plugs are regapped to .28

The car loves to hit full boost on the interstate and stay there, but sometimes when I floor it on take off there is a hesitation and backfire either in first or second gear at about 16 psi.

Is this my injectors or timing?
Title: Hesitation
Post by: Carl on May 08, 2011, 07:31:13 PM
Just to clarify before I make anyone mad :)

Yes I checked other threads, and yes I have read that the stock injectors can handle 18 psi.

Was I misinformed?

Either way I am going to buy new injectors this week.  Up to what # injectors can a stock ECU handle, and where is the best place to buy them.

I was thinking Stinger, but if there is a better place please let me know.

Thanks!
Title: Hesitation
Post by: Carl on May 12, 2011, 05:31:53 PM
Ordered a Kirban FPR.  After some research I found out I need to raise the base fuel pressure to max out the stock injectors.  Hopefully this works, I will keep ya'll updated. :hick:
Title: Hesitation
Post by: mcb82gt on May 12, 2011, 06:37:06 PM
I was gonna ask what your base fuel pressure was.  Sounds like your already on the right track.
Title: Hesitation
Post by: 88turbo on May 13, 2011, 11:12:31 PM
have you dialed in your TPS to .97v-.99v?
Title: Hesitation
Post by: Carl on May 14, 2011, 02:03:21 AM
I haven't dialed in my TPS at all actually.  Not only that, but my IAC is broken so I leave it unplugged.

All my troubles were fixed with a full tank of gas, so I am about 99% sure it's a fuel pressure issue.
Title: Hesitation
Post by: 88turbo on May 14, 2011, 07:24:53 PM
Quote from: Carl;359878
I haven't dialed in my TPS at all actually.  Not only that, but my IAC is broken so I leave it unplugged.

All my troubles were fixed with a full tank of gas, so I am about 99% sure it's a fuel pressure issue.

that has nothing to do with your fuel pressure...  if your IAC is broken I have a handful of them cover shipping and I will send one your way, it is very important that it is plugged in.
Title: Hesitation
Post by: Carl on May 17, 2011, 04:28:55 PM
Quote from: 88turbo;359915
that has nothing to do with your fuel pressure...  if your IAC is broken I have a handful of them cover shipping and I will send one your way, it is very important that it is plugged in.

I will use one from my other bird as that one works.  I appreciate the offer!  Now I am curious why the problems only start once I get to about 1/4 fuel left in the tank?  If it's not fuel pressure, what could it be?  Do I need a sump or something?
Title: Hesitation
Post by: Carl on May 18, 2011, 03:41:45 AM
Ok, so I think I found the problem.

One of the tubes on my fuel sending unit was cracked.  It's the send tube, not the return tube.  It's actually cracked so bad it has almost broken free from the rest of the unit. 

I attached the new IAC sensor and the car revs at 2000 rpm at idle.  I am going to try to adjust the voltage of the TPS and see what happens.
Title: Hesitation
Post by: Carl on May 23, 2011, 12:00:37 AM
Does anyone know where I can buy a new fuel sending unit for a decent price?
Title: Hesitation
Post by: Carl on May 28, 2011, 06:03:01 AM
I have good news... I fixed the problem.  I just took the fuel sending unit out of my white bird and put it in my daily.  The hesitation has also stopped.  Also, I cut a door to the tank from the trunk for easy access.  Once I get it looking nice I will take pictures. :)
Text only | Text with Images