Hey guys, <br><br>Ordered my two Dakota digital gauges today. I can't wait to see how my CTD is actually doing.<br><br>Here's my next question. I just got back from Montana this afternoon and my mileage was only 9.5-10.5 mpg. (Total trip was 1000 miles) I consistantly kept my speed to 65 mph. I was in 5Th most of the time unless I needed to goto 4Th for a real steep hill. (Don't forget I was carrying my 4700# camper ontop) Does this milage seem reasonable to you? <br>I read a few posts about the Cat being plugged. A few more about the timing being off. The other weird symptom was that when RPM's (and in 5TH) were about 2500 and only near sea level, I got pinging!! I know what I heard and I am sure that the altitude was pivital. Valves were adjusted by dealer two weeks ago. What gives? Why the lousy gas mileage?:P

 

Well it has room for inmprovement I'll give ya that!

You didn't say whether or not you have 4.10's or 3.54's but being a dually I'm gonna guess 4.10's. Well with 4.10's you won't get MUCH better put you can improve it some.

You cat could possibly be plugged if in fact you have a cat and not a resinator. Take it your local muffler shop and have them check it out. If its a resinator then have them chop off that 55 gal. drum you have as and OE muffler and install either a straight pipe ;D or a better diesel muffler (i.e. NO FLOWMASTERS)

If you really wanna see an improvement in your mileage find a DTR member in your area or a good diesel shop with a timing kit and have you injection pump timed to 16* BTDC. That alone gave me 1.5 better MPG at the pump. ;D
With 160K miles on your truck I will swear to it that your factory timing has slipped. My 97 had 134K on it when I did the timing and it had slipped from factory (13.5 BTDC) all the way down too 10 or 11 BTDC!

If you do those 2 things I say you'll see a nice improvement in mileage, but not a dramatic improvement.

 

Thanks Got smoke?,<br><br>I updated my profile. As happy that having a 4.10 rear makes my truck attack the hills....I hate the poor fuel economy.<br><br>I too am thinking the timing is retarded a bit. I thought the pining is a real clue.<br><br>I didn't know that a CTD could have a reasonator versus a muffler. Now you have me thinking.....<br><br>I am going to a Diesel specialty shop tomorrow. I will pay to have him adjust the timing to 16 degrees.<br><br>Thanks.

 

Hi Dually,<br>Pinging that you talked about could be a sign of an internal leak in your injection pump. Mine did that and it was still under warranty,took to the dealer,they sent it out and all anyone could tell me was that a nylon bushing had worn out and was replaced with a bronze part. I was told I would never have that problem again. Probably was the overflow valve,you may want to remove yours to check it.<br> Tony

 

Thats a darn good idea. I would suspect that my mileage would suffer as a result of that overflow valve too. It looks like I may have more than one problem.<br><br>1. Timing needs adjusted anywaty<br>2. Overflow valve----How do I replace this valve? If I remember, this is the the one atop the pump. <br><br>TJ

 

UPDATE,.......<br><br>Today I went ahead and replaced the fuel overflow valve. What A difference. No more ticking! <br>I also found out that a bolt on the driver's side of the center/rear of the engine had been removed. The hole was allowing exhast gasses to escape! It was totally affecting my boost. The bolt looked like a 3/8's or so. <br>Now I know why my engine would cut out after about 2500 rpm's and loose power. <br>Next week, gauges and timing to 15.5 degrees. ;D ;D<br><br>Thanks guys for your suggestions!<br><br>TJ

 

[quote author=97Dually link=board=16;threadid=9561;start=0#92223 date=1042608198]<br>UPDATE,.......<br><br>Today I went ahead and replaced the fuel overflow valve. What A difference. No more ticking! <br>I also found out that a bolt on the driver's side of the center/rear of the engine had been removed. The hole was allowing exhast gasses to escape! It was totally affecting my boost. The bolt looked like a 3/8's or so. <br>Now I know why my engine would cut out after about 2500 rpm's and loose power. <br>Next week, gauges and timing to 15.5 degrees. ;D ;D<br><br>Thanks guys for your suggestions!<br><br>TJ<br>[/quote]<br><br>Go to 16*, may not make much difference but I got my 1.5mpg better @ 16*

 

97Dually, When you get the work done on your timing, please post where<br>you had it done, and how you liked the service. I am looking for someplace<br>to do mine, also. I haven't ever towed or hauled anything, but I usually get<br>between 18 and 19, driving about 60 miles back and forth to work on back<br>roads and freeways.<br><br>Thanks...