1995 coachmen catalina

[jac730]

w/460 fi I have replaced the fuel pump and filters,when idling step an the gas it revs then backfires also when driving it loses power,backfires.it will idle but when I try to accelerate it bogs out, any advice would be helpful

[Donlock]

Mass Air Flow Sensor??

[subford]

You do not have a "Mass Air Flow Sensor" yours has a MAP sensor.

First you should run the EEC Self-Test and see if you have any errors with the electrical with the KOEO self-test. Then check for codes in the CM.
If you get a 111 on both then run the KOER self-test and lets us know what codes you have.
Get a $30.00 code reader to do the test that reads out the numbers and dose not flash a LED form a auto parts store or Amazon.
Here is the best one to get from either place and comes with a book on how to use it:
Amazon.com: Equus 3145 Ford Digital Code Reader: Automotive

For a fuel problem check:
Leave the dog house off and hook up a fuel pressure gauge to the fuel rail.
Take it for a rid and see if the fuel pressure holds while it loses power & backfires.
I would think you would be at WOT when this happens so the fuel pressure should be about 40 PSI on the gauge.
If it is less than 35 PSI try changing the fuel filter.
If that does not fix it change the fuel pump with the new type fuel pump from ford for this problem as in the TSB.
Normal fuel pressure should be 32-34 PSI at idle, 40 PSI WOT and 45 PSI if you pull the vacuum hose off the Fuel Pressure Regulator (FPR) while at idle.
If you pull the vacuum hose off the FPR and you see any fuel at all the FPR is bad.
All fuel pressure checks should be done with a cold engine and have a fire bottle at the ready.

Also check all vacuum lines and fix any bad ones.

[jac730]

no codes but it seems to be running really rich the exhaust fumes are strong

[jac730]

ok I messed up on the eec iv test scan and code 311 thermactor air system inoperative i checked the hoses comming from the pump and around the valves and they seem to be getting air but its a pulsating like pressure. but when you raise the rpms its like the pressure drops instead of getting stronger,should it be a steady air pressure.there are no leaks in the lines,im just grasping at straws maybe a bad pump,and i tried to find the 1 and 2 air bypass valves everywhere even on the net no luck,hopefully someone knows something about this

[subford]

Did you get the 311 during the Key On Engine Running (KOER) self-test or with the engine not running with the Key On Engine Off (KOEO) self-test or Continuous Memory (CM) read out?

Did you use a code reader or count the flashes of the MIL on the dash?
If you got the 311 on anything but the KOER then you did not get the code right as it only applies during the KOER self-test.

That said a DTC 311 indicate the Secondary Air Injection system is inoperative.
Possible causes:
Vacuum hoses damaged.
AIRB/AIRD valve inoperative.
Air Pump inoperative.
AIRB/AIRD solenoids damaged.

Visually inspect vacuum lines for disconnects in the AIR system.
Visually inspect for proper vacuum line routing. Refer to VECI decal.
Visually inspect Air Pump for broken or loose Air Pump Belt.

You would not happen to know your calibration code for the F53 do you?
With this code I could look up the part numbers for your A.I.R. parts.

[jac730]

I bought a good code reader that gives you the code number read out and i had to do the koeo it read code 111 then i did the koer and then it read code 311 managed thermactor air system inoperable I checked everything for leaks nothing seems to be visually wrong,I ran it felt the hoses and i could feel the pressure pulsating so im kind of stumped.I found a guy on the net who has the parts and he sent me a pic its the same type of setup but the air control valves look different im thinking of having him send them to me or maybe someone out there would know if they would work he said they are from the same year and engine size any suggestions would be greatly appreciated oh yea someone told me that it could be a possible problem with the upstream 02 sensor

[tderonne]

Not sure if the 460 has the same type fuel pressure regulator as other Fords of that era or not. But if it does, there's a good chance it's bad. The diaphragms rupture and let fuel flow via the vacuum line into the intake. Fuel pressure control also suffers.

Your symptoms don't match 100%, but depending how bad the regulator may be, the symptoms can change a bit.

It's easy to check. There shouldn't be fuel in the vacuum line at the regulator. Be careful, fuel can come spraying out.

[jac730]

alright now I did it, I went and changed the fuel pressure regulator,when i started it I let it run to normal operating temperature and it still backfired on deceleration so I figure wtf I will scan for codes again the koeo came back 111 normal when I started it to run really rough and was blowing black exhaust this time I got code 126 map voltage above spec so tomorrow Im going to change the map sensor, this is really pissing me off but I am determined

[tderonne]

Could be a vacuum line to the MAP sensor...

[gary peterso]

What did you find out?

[jac730]

havent had a chance to check it

[jac730]

does anyone know where the map sensor is on a 1995 coachmen catalina 7.5 litre I cant find it

[RLS7201]

Quote:

Originally Posted by jac730 does anyone know where the map sensor is on a 1995 coachmen catalina 7.5 litre I cant find it

Inside the left side of the dog house, adjacent to the gas pedal. Or just follow the plastic vacuum line from the back of the throttle body.

Richard