'93 7.3 EGT issues

Frisbee650

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Hi all. First time poster, but I have searched and used the forum any time I am working on something. A little about me, I am a Ford and diesel fan, I have a ’93 F-250 IDI with 160,000 miles and an ’01 F-250 Power Stroke with 340,000 miles. As the title states, I am having an EGT issue with my ’93, and was hoping for some help and input. I am not a mechanic by any means but am able to get things done with the help of the web.

This is going to be a long post, hopefully I am trying to supply all the necessary information for some help.

I bought the pick up last November with the intentions of turning it into a camping rig I could use for quick trips, due to life and other issues it took me until May to put a complete tank through it. The truck came with receipts for a bunch of recent work including a new injection pump 3 years and 12,000 miles ago. I started using it a little more this summer and noticed on trips into the hills with nothing in it besides me, my daughters, a dog a cooler and some chairs that it was blowing black smoke on the grades we were driving up. Started doing a little research and became worried that the fuel had been turned up by the previous owner. The truck wasn’t smoking like some of the kids you see around town, but I could make it blow pretty good if I got on it. I installed a Pyrometer per the following web site, I used the exact gauge and installed the probe in the same location they did.

http://www.dieselhub.com/performance/idi-pyro-install.html

Once the installation was done I took the truck on a test drive completely empty on the interstate where there is a grade with the cruise set at 70 MPH the EGT’s immediately went to 1,100 degrees and stayed there until I topped the grade. I then turned the fuel down one flat and repeated the same test; the EGT’s dropped about 150 degrees and the smoke was completely gone. Even though this didn’t seem like it was enough of a reduction I hooked a 12x6 enclosed trailer with a washer and dryer in it and headed for the hills to pull some grades. Before I could even get to the grades I hit 1,200 degrees on the little hills going out across the desert, I never saw smoke. I began to wonder if something else was wrong so I started doing more reading and research. The only other item I could find that would affect EGT’s was the CDR valve. I removed mine and cleaned it, it was full of oil and there was evidence of oil getting into the intake. In the end I ordered a new one and installed it. Last night I hooked the same trailer up and headed up the same route as last time. I got across the desert under 1,200 degrees, but as soon as I hit the grade I had to left off and shift down.

There have been several weeks in between each of these drives, I don’t know how much the conditions outside are affecting the temps.

I am not sure where to go now, I am thinking I need to turn the fuel down again, with the fact the smoke is gone, and I have no idea if the fuel was actually turned up, I am not sure that is the right thing to do. Can you hurt anything by turning the fuel down to much? Anyone have any suggestions or advice? I would like to drive this truck on a 2,400 mile road trip next week, but won’t unless I am comfortable it is good to go.

My ’01 was being used by someone else for a while this summer; I almost started using the ’93 to pull my 26’ camp trailer before I installed the pyrometer. I am sure glad I didn’t.
 

Thewespaul

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The only thing I see you hurting is performance, but if you dont have any smoke lets start on some other things.

High EGTs are caused not only by unburned fuel passing through the engine, but also unnecessary restriction on the exhaust and intake. This inhibits your the gasses that enter and exit your engine to flow freely. This causes unnecessary preasure in the system which create heat, your EGT problem. Usually if their is a big restriction on the intake you get big smoke but this is unlikely since you dont have smoke anymore. However, it is possible you did at some time have a large restriction on your intake causing the smoke even though the IP is stock calibration. To fix this is quite simple, you need to de-restrict your exhaust and intake.

The most popular option with the exhuast is to straight pipe through where the muffler is located, upon removing the muffler completely. This is what I have done and although it is loud it has a nice tone and the increase in performance was noticeable. For the intake I would make sure that your air filter is clean. If it is then I would consider ditching the factory air assembly and making a cold air intake. There are plenty of threads available for your instruction on this

After freeing your engine your EGTs SHOULD drop noticeably, I personally would turn the IP back up until their is little to no smoke and you will be gravy!
 

IDIoit

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does this truck have a turbo on it?
i would free up the intake and the exhaust as stated above.
adding more are (turbo) will drop your EGT's too
 

Frisbee650

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The truck does not have a turbo. It does have straight through exhaust already, forgot to mention that. The intake appears to be stock and severely restricted by design with a hose going from the filter housing to a plastic fitting mounted above the drivers side battery, it is clear, one of the first things I investigated. Would removing the hose and letting the intake pull unrestricted air from the engine bay be a good test? It appears to have an aftermarket K&N type air filter that appears fairly clean. I will clean or replace to see if that helps. I have read a little bit about cold air intakes added to these trucks. From what I have seen cowl induction looks fairly easy but not the most desirable. Under the hood looks more complicated, will have to start studying posts.

Thanks for the replies.
 

fsmyth

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Those numbers are somewhat in line with mine.
Really was an eye-opener to see how fast the temps climbed when
you started loading it (speed or weight).,
Mine is N/A, no mods, factory air cleaner open to engine compartment.
Took the factory duct that was on top of the radiator cross-member off
because it looked like so damned little intake area. Didn't seem to change
EGT's or performance.
Stock exhaust with muffler. No smoke, exc. on start.
 

FarmerFrank

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With straight pipes and a factory intake hitting those numbers I point the finger straight at timing.

Look at where you injection pump bolts to the injection pump gear housing. On the pump and housing is a scribes line. See if those are lined up. If so loosen your pump and give it a 1/16 of an inch bump one way or the other and see which way helps the most.

Does your truck rattle like the power stroke or does it seem to be very smooth? You want just a hair of rattle but no where near power stroke.

Ideally you want to find someone with a timing meter to properly time it.
 

Frisbee650

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I misspoke in my previous thread the truck does not have straight pipe exhaust. The timing mark on the injection pump is about a 1/16 to the right of the timing mark on the housing. I think the first thing I will do is eliminate the muffler and go from there.
 

sjwelds

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There's also the factory crossover/y-pipe to consider. Where it comes across from the driver's side and joins to the passenger side there are some quite restrictive areas. On mine (before I turbo'd it) I actually fabbed my own junction to where the two pipes fed into one 3" or 3-1/2" pipe much more smoothly than factory. I don't know what my EGT's were before/after as I didn't install a pyro until I did the turbo. I also installed a Hypermax cowl induction tube to help the intake side of things, but there again, no data to compare.

Cowl induction: http://www.gohypermax.com/ProductDisplay.aspx?ID=498d3ee6-44a5-427d-9e97-bf310348184d

JM2CW
 

riotwarrior

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Cowel induction for cooler air

Less restrictive exhaust

TIMING plenty of threads here on timing to read up

Turbo

JM2CW
 

FordGuy100

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Downshift and see what they do. Timing and injectors will play a role. I always like to say add a turbo, but for most thats not possible.
 

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