OK,

Here goes..


I have a 92 Bronco with 5.8... About 135,000 miles..

Recently she started acting a little ill.. Out of no where, my Check Engine light will come one.. She will start to stall.. If I can get the throttle fast enough, she'll come up and run rough, acting somewhat like it is losing fuel..


My pump has been screaming in the tank for a while now, but I decided to run one of those do it yourself diagnostic tools on it..

What I came up with was a slew of codes, some indicating EGR Voltage low, Manifold Pressure, and Distributorless ignigtion system.

Has anyone out there had a similar problem, and if so, what was the outcome.. I hate bringing the older vehicles into the shop, they have a fantastic way of ensuring that they need about everything..


Thanks in advance.


Glenn May

 

Can you tell us the exact code numbers that you got? That will help in figuring out your problems better. Manifold pressure error might indicate you MAP sensor is bad. Egr voltage could be the egr valve position sensor.

 

The codes off of my reader (Which is not exactly a top quality) but they are as follows..

111
122
327
22
327


Thanks
Glenn

 

Sorry, Here are the breakdown

122 - Throttle position sensor below minimum voltage.
327 - EGR Valve Position Sensor Fault
22 - Map or Barrow sensor our of range...

G

 

122 is a tps circuit fault and probably means you need to replace the throttle position sensor. 327...again probably your egr valve position sensor. 22 is most likely the map sensor needs to be replaced. I would first check for loose wires at these components and if they are ok then I would go ahead and replace these parts.

 

Thanks for the reply. I have a dumb question for you then to reply to this.. I will check wires, but when I purchased the truck, I noticed that the exhaust system is slightly smaller than any other that I have seen.. by atleast 1/2 inch.. Could this be causing the failures of sensors, or is there a circuit that could be going bad on all of them.. Furthermore would those failures cause the truck to try and stall?


Sorry for being a pain.. Thanks again for your answers.


G

 

These sensors and devices just fail over the years from heat and regular use. Everyone eventually has to replace a lot of their sensors and other little components. The exhaust system being smaller wouldn't effect any sensors. Those few components that you supposedly have bad really affect the truck performance and they must be working right for your truck to run right.

 

Ok, there are three problems that I can see here so far.

FIRST, EEC-IV computers only generated either three-digit or two-digit codes. The Code 22 is out of place here.

The SECOND problem is that Code 111 is a "system pass" code meaning that no faults were present during the KOEO or the KOER.

The THIRD problem is that BOTH of the other three-digit codes are telling you that the voltage coming BACK to the computer from the sensor is too low. This leads me to believe that the "reference voltage" that the computer is SENDING may be too low to begin with. The reference voltage is +5 VDC (Volts Direct Current){Also referred to as VREF}.

It is possible that BOTH the EVP (EGR Valve Positioning) and TP (Throttle Positioning) sensors are bad however, its a simple voltage test to determine whether or not you need to spend a bunch of money on replacement sensors. Be sure to test the VREF at the connectors for the sensors. (Key must be "ON"). The BROWN/WHITE wire at each of these sensors is the 5VREF from the computer. You should get a + 5 VDC reading across this wire and ground with the key "ON". You can also check this voltage from the BROWN/WHITE wire at pin 26 of the ECA (EEC-IV computer) behind the passenger side kick panel. Some models may have an ORANGE/WHITE wire at pin 26 instead of the BROWN/WHITE one.


It should also be noted that the symptoms you described are perfectly consistant with the three-digit error codes generated.

 

Its the simple things that are overlooked sometimes. Start with the basics by checking fuel pressure, spark, battery connection/condition. Start with the simple-free things before buying new sensors. There are multiple problems so start with what you know. The fuel pump is screeming.

Good Times

 

The pump has been making noise since day one.. There are no codes indicating low fuel pressure.. Although that is certainly something to be concerned about..


Think I will go tap out all of the voltages, see if I can see something easy first..


Thanks to all.. I'll post my results.


Glenn May

 

Fordfuelinjection.com has a good article in regard to how to test TPS voltage. I had to do this just recently and found that the TPS was bad.

0.85 v at closed throttle and the most I could get at Wide Open Throttle (WOT) was 1.85 v. Should be closer to 5 volts at WOT.

 

Since you first put code 111 in the first list, the self test seems to have passed. the other codes are stored when driving and may have been there for years if the battery was never disconnected although Im not sure if memory codes get erased automaticaly after a certain time. You might want to clear the codes first and then do the tests again.