96 Bronco

[George Coleman]

I have a 96 Bronco 351, Starting after it has set for 30 min or so, it stumbels like staving for fuel but it smooths out in about 5 to 10 seconds. Feels like a heat soak problem, there are no codes or check eng. light in the winter time when cold no problem. Any ideas Thanks

 

[miesk5]

yo George

Without Codes, we'll need to go through the Fuel sys according to this chart by Charlie Probst;



Down bit is Vacuum leaks; does AC air flow work well? Such as AC air flow is not diverted from registers to defroster ducts on acceleration?

See my VAC Leak Test here @ http://broncozone.com/topic/22770-low-idle/

One sensor that may be an issue w/Out Codes is the Idle Air Control (IAC); also called, Idle Air Bypass (IAB), Idle Speed Control (ISC), Throttle Bypass Air, Idle Bypass, Inlet Air Controller, Inlet Air Bypass, Intake Air Bypass, Intake Air Control

provides additional air to maintain the proper engine idle speed under varying conditions when commanded to do so by the Powertrain Control Module.

Installation & Cleaning by Bobby (blue)









Testing & Cleaning Source: by Seattle FSB (SeattleFSB)

 

[George Coleman]

I have replaced the IAC and the temp sensor as well?? The AC works fine no leaks there! Could there be a fuelinjector leaking down or fuelpressure reg. be bad?

 

[miesk5]

I have replaced the IAC and the temp sensor as well?? The AC works fine no leaks there! Could there be a fuelinjector leaking down or fuelpressure reg. be bad?

Yo GEORGE;

fuel pressure reg (FPR) test; pull vac line off, any aroma of gas or gas in line; replace FPR bec diaphram is bad

fuel injector

Pintle Crack pic "...Here's what a mostly-cracked pintle cap looks like. Napa sells replacements, part 2-15018, for $0.39. It beats buying new injectors..."

Source: by Richard C (Bigric, Money Pit) at http://www.supermotors.net/registry/4584/16165

Fuel Charging Gasket Kits Depiction; This kit contains the necessary replacement gaskets and “O” rings for fuel rail, injector, pressure regulator and throttle body service. - 80.6 MB pdf

Source: by Ford at http://www.fordinstallersupport.com/files/catalogs/fes200.pdf

Exhaust Color Diagnosis; Smoke,

Black Smoke: Black exhaust smoke is an indication of rich fuel condition. These are possible causes:

Fuel Injectors: A leaking fuel injector will cause a rich fuel condition.

FUEL PRESSURE SPECIFICATIONS

Key ON

Engine OFF

35-45 psi

Pressure Test Gauge Overview & pic; "...To test the fuel pressure you’ll need this tool. You will need to ***** it onto the schrader valve on the top of the fuel rail, it looks like a tire air valve stem. After attaching the fuel pressure tester, run the fuel pump for 10 seconds. Check that the pressure is within specs, and it doesn’t leakdown more than 5PSI within 60 seconds after pump shutdown..."

Source: by Ryan M (Fireguy50) at http://oldfuelinjection.com/?p=12

 

[hoghappy]

I have a 96 Bronco 351, Starting after it has set for 30 min or so, it stumbels like staving for fuel but it smooths out in about 5 to 10 seconds. Feels like a heat soak problem, there are no codes or check eng. light in the winter time when cold no problem. Any ideas Thanks

I had those symptoms plus could smell gas...and engine was surging. Pulled vac line off top of fuel pressure regulator on my 93 5.8 and it had a little hint of gas in it. While motor was running I disconnected vac hose to the top of the regulator and could see gas coming out the tube when I placed connector close to where it connects.

A new one solved my issue. It took about an hour to replace....I could slap the engineer that designed the 3 upside down allen bolts. It took 30 minutes to get the back one that you can't see out. Other than that...it was a piece of cake.

I found a trick after about 15 minutes of trying to get the allen on that back bolt. I used a allen with the ball on the end once I got the bolt broke loose. I could then leave it in the bolt the rest of the way out. Worked great on getting it snugged back up too.