I have a 97 F-350 with the original set of injectors, the truck has 122,000 miles on it. I'm reading a lot about stage 1 injectors. I would like to know what real benefits a person would see if he changed from the stock injectors to these stage 1 injectors. Would you suffer a mpg loss, providing you kept you're foot out of it? Also, I have a problem and not sure what it is related to, other than the engine getting up to operating temperature. When the engine is cold the throttle response is like a gas engine, very quick and responsive to throttle, but once the engine temperature gets in the normal band the engine gets almost hestitant when the throttle is pushed down, any ideas of what to look at for a problem.

 

mine was the same way but yours might be another problem. I advanced my timing by adding a resistor in lint on the oil temp sensor I only added a 2.2k but I was told the 4.1k works the best, BUT!!!! Comes at a loss of exhaust temp which gives you less boost thats why I only did the 2.2k. Well enough about that tell us more about the truck what is done to it? Mods.? Fpr shim? Its worth it! 10K mod.? intake anything? someone esle will chime in with their knowledge soon too.

 

I don't think your problem would be the injectors, may have other sensor-related problems here... I'd wait for a couple other guys to chime in... If you swap out you injectors, and get a good custom burned ship with an economy tune anf keep your foot off the floor, fuel millage won't get worse. It's when you start pedaling that your millage goes down. I'd hold off for now and get your other issue solved first.

-Robb

 

Stroker: My 97 was doing the same thing and it drove me crazy. Bill (Madvan) helped me figure it out. It was the thermostat. I found the problem by plugging into the data port and found that my engine oil temp was mostly staying around 155-160 degrees. I got a 203 thermostat from Dieselsite and the problem was fixed. Dieselsite also has an aluminum thermostat housing that is worth getting if yours is rusted. It runs so good now that I love to keep my foot on it. Another symptom I had was that it would take off and try to run above 200 rpms. Also, on the Dieselsite page, you will see that Ford recommends replacing the thermostat every year.

It is cheap to try it out and I bet your thermostat is the original. If you can get your hands on something like an Edge tuner that allows you to read real time engine data, you will see that the new thermostat will make your EOT run in correlation with the water temp. It is also worth the 30 minutes it takes to install a good water temp gauge. Good luck and I hope this helps.

This is the link to the 203 thermostat:
http://www.dieselsite.com/index.asp?...ROD&ProdID=186

 

Sorry, I meant it tried to run good at 2000 rpms.

 

Thank you for the feed back guys, Knotwild I have actually replaced the thermostat but it was with a 192 degree thermostat. I suspected it being faulty, because the temperature never came into the middle of the gauge. Is there a way to purge air from the coolant system prior to start up, when you replace the thermostat? If I remember right, I think I had an air lock for a short period the last time. I think you may have a good idea, I'll give it a try. Hard to believe 8-11 degrees would make that much difference though. Thanks again, will post the results after I complete the replacement

 

My temperature also stayed low, in fact it never reached the the first letter in normal. If you can find something to read the data stream with then you can check your oil temps. The PCM uses the oil temp to set the timing. Mine is now running 200 or so degrees. I installed the thermostat and never purged anything. Gravity should keep the waterpump primed. Depending on where you got the thermostat, it might not even be the right one.

Once my truck warmed up some before the thermostat, it would almost make you think the engine was missing on at least one cylinder and the gearshift would even shake.

At any rate, I hope it helps and I look forward to hearing what the final fix is.

 

Remember guys, the stock gauges are pretty much pointless. Get a scanner or buy a cheap oil temp gauge to find out what the PCM is seeing for temps.

I've never heard of an air lock being a problem on our trucks. I guess it might be a problem is pressurized systems though.

 

Knotwild,
Just wanted to thank you for your input on my problem. The 203 degree thermostat did the trick. Man, how sweeeet it is. Throttle response is great, shake in the gear shift is gone and the idiot gauge reads slap in the middle. Took 15 minutes to replace, time well spent.

 

Great Job guys!! 1997stroker thanks for the update!! that is very important to this place!!

 

I am really glad to know that it helped Stroker. Bill (Madvan) was the one who knew the answer to this one. I think there are probably a lot of guys out there with a similar problem, but it might not be so evident in an automatic because it would just downshift and rev up.

 

Well done Knot!!!
Its the difference between a running PSD and a good running PSD.

stroker enjoy the new found cab heat and MPG.

On a WAG more than 50% of the PSD's on the road run to cold!!!

Bill

 

I had no idea it would make that much difference Bill. I wish everyone could have driven the truck before and after. You had the problem pegged from the beginning and if you hadn't helped me, I hate to think how much money I would have wasted and still had the problem!