Community Forums

jac730 · 06-22-2010, 08:45 PM

I own a 95 coachmen catalina with the 7.5 litre engine and i have posted about the managed thermactor system I have searched high and low for parts for it no luck does anyone know if I could interchange with a different model or a newer year

HotMech · 06-22-2010, 10:50 PM

If you can find the "Calibration code" It will look something like this:

95-E50-R10 not those numbers but that format. It will make it a lot easier.

I will do Some research from the shop tomorrow, and let you know what I find.

Kerry

subford · 06-23-2010, 08:13 AM

Is this a class "A" or "C" Motorhome?

The thermactor system will not cause the problem you are having.

Sounds more like the engine is running too lean. I would put a fuel gauge on it and see what you are getting (fuel pressure dropping) when this happens.

I know you said you replace the fuel pump and filters but maybe the fuel pump relay is bad or other wiring problem. The gauge will tell you it is in the fuel system or not.

Also was the engine timing set with the SPOUT still in, if so this may cause these problems also.

The SPOUT must be removed when setting the timing at 10 BTDC.
The fuel pressure should be 30-34 PSI at idle and 40 PSI at WOT or 40-45 PSI with the vacuum line removed from the Fuel Pressure Regulator or pin #6 of the Self-Test plug grounded and the key on and the engine not running.

jac730 · 06-23-2010, 06:16 PM

this is a 34 ft class A

jac730 · 06-23-2010, 07:34 PM

the calibration code i found is 5-98A-ROO

HotMech · 06-23-2010, 08:01 PM

Jac730, I will look into it first thing tomorrow morning.

I went back and read som of your posts about the '95.

I'll know more when I look up the calibration code, but it seems you may have more than one problem. doesn't sound major though.
Most thermactor A.I.R. failures are just broken vacuum lines.

What I get from some of your earlier posts, is that it is running rich.
Check the Red vacuum hose going to the Fuel pressure regulator, for fuel. Ford Has had a problem with those regulators failing and then fuel bieng drawn into the engine via that hose.
Some suggest that it may be running lean, and that could be the case. That too can cause a quite strong smell, very harsh and burns the nose a bit

subford · 06-23-2010, 08:19 PM

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subford · 06-23-2010, 08:38 PM

By the way just for curiosity where on the Motorhome did you find the calibration code?

jac730 · 06-24-2010, 02:59 PM

who ever owned it before me had it all in the owners manual that came with MH sorry its not much help considering the immense help you have been thank you so much

HotMech · 06-24-2010, 10:20 PM

My Ford guy was out today, go figure.
I'll check with him tomorrow.

However, I do agree with subford here. Bogging, loss of power and such is not caused by the Thermactor System. You have a fuel problem, be it to much or too little. the Thermactor system, if it has a problem, can and will "mess up" the readings on an emmission test, and may make it fail, but it will not have much of an effect on drivability. Without knowing specific tailpipe readings we are all just taking a stab in the dark. but bogging, and intake backfires, are usually resultant of lean mixtures.

FYI The 460ci or 7.5L Ford, is very receptive to added base timing. Ford calls for 10 deg. btdc. on all EEC IV opperated engines it built.

the 460 has a huge combustion chamber, with a very offset spark plug.
460's of the carburated age. would love 19-22 deg btdc todays EEC IV setups. can manage much better fuel economy and lower coolant temps with 15-18 deg. btdc
Higer altitudes can use even higher initial advance numbers. This by the way, is using regular grade fuel, 85 octane at altitude and 87 at sea level. And, if it has those damn "buggles" in the Air intake hoses, cut em out!