EGT Problems (too low)

I noticed that my pyro was reading lower than normal. I would cool down to 200° After idling up the driveway to park. This struck me as ood so I went driving and couldn't manage to get the pyro up to 1000 even with a hot chip & stock injectors, I've hit 1300+ with them so I knew something was wrong. I came back home and started "testing" even running 3000RPM in park the pryo wouldn't go above 325° So with an IR thermometer I compared the manifold to what I was getting on the pyro. They were reasonably close. I pulled out the propane torch and heated the pyro probe up and the guage showed the increase and could be pegged but the response was rather sluggish. The pyro and probe are still under warranty so I called the vendor (GOS racing) described the problem and he said well I'll send you a new pyro and probe figure out which is the problem and I'll issue a call tag for the leftover good pieces.

The new pieces showed up today and with any combo of the new pieces and old pieces with the truck in park I still can't get the pyro to go over 325° So I've got a problem.

Since I bought the truck I've had a lope at idle when I start the truck but it goes away after a couple seconds. In the timespan I've been testing the truck to figure this out I have developed a miss that isn't really noticeable at idle but shows w/ great hood vibrations @ 1500. I've pulled out the IR thermometer again and tested the temps on the manifold next to the different cylinders. The front cyl on the driver's side (side w/ probe) is 15° cooler than the coolest of the rest of the cylinders on that side. Testing the passenger's side there is no difference (2-3°) between any of the cylinders. So I pulled the valve covers off figuring that when I replaced the VC gaskets and some of the UVC harnesses & GPs I didn't get that injector cliped back good but it's connected and squirting oil. I've started disconnecting individual injectors and can't hear a noticable difference between one and the other being disconnected at idle or up to 1500 RPM.

So any suggestions for soloutions to the problem for diagnosis of what I'm going to guess is an injector that is failing and not delivering the full fuel load to that cylinder. And unfortunately upgrading injectors isn't really in the wallet right now other wise I'd be all over that.

Thanks
Brandon

It really sounds like you have plugged injectors, maybe Bean will chime in here and shed some light on this one.......... At 325°F pyro temp and 3000 RPM (close to WOT) you should have crazy white smoke, thats just not enough combustion chamber temp to burn the fuel you should be injecting.

If in fact you do have a bum (several bum) injectors, you can replace all 8 with Beans Stage I's or a Baby Swamp cheaper than you can go for reman's from Ford. That is assuming you have more than two injectors not delivering properly which is what it sounds like to me.

Smoke or no smoke? wont get over 325 at all? Even WOT on the road? Where is your probe? Make sure you gauge has a good ground.

WOT on the road I can get it up to 600

No black smoke in the driveway I'm getting some blue smoke and it turns to a white smoke but it's only a light haze.

It's been suggested to check the poppet valve screw they weren't loose.

Pyro is mounted @ the end of the driver's manifold, drill & tap into the manifold. Ground is good.

BJS said:

he said well I'll send you a new pyro and probe figure out which is the problem

Click to expand...

What about the wire between them? I have had problems with pyro's on big trucks many times and more often than not it is the wire close to where it is attached to the probe pigtail. The engine vibration seems to work the solid wire a little until it breaks.

Crumm I did try a new wire too he sent me the probe, guage, & extension wire

I think I've figured out the problem and it comes down to injector o-rings i had 2 that had gaps in the 2 part o-ring since these were still the factory '95 o-rings and they hadn't been update I'm hoping that was the problem, of the 8 injectors the middle o-ring showed problems on 5 of the injectors though since I didn't want to replace o-rings and then turn around and pull the injectors later this year to upgrade them I decided to drop them in a box to bean so we'll find out if there was a deeper problem with the injectors or if it was just o-rings when he gets them next week.

I'm sure BDP Stage1's will help fix having low EGT's

Just to update this thread since my problem is solved now for the future when someone is searching and finds a similar problem.

I pulled the injectors and sent them to BDP to upgrade them to his stage 1 injectors and to check to find out if there was any internal problems with the injectors. What they found was a couple broken springs, poppet valves that were out of clearance, and a couple scored plunger & barrel assemblies. I got them back and installed them and found that there wasn't any increase in the EGT in the brief drive I took w/o chip (somewhere in the diagnosis process the chip came out) so the next thing I began thinking was a lack of fuel so I checked fuel pressure and it was about 68 PSI @ idle but dropped off when I reved the motor up in neutral . With a mirror I checked the weep holes on the pump and found that they were leaking so I replaced the fuel pump and all of the fuel hoses burried in the valley.

While the fuel housing was out I decided that I would install the IPR o-rings that I had bought. I swapped them out and found one to be almost gone so definately worth the time. I attempted to clean the IPR while I had it out. Once I got it back together I had a problem with throwing CEL (code unknown) and loosing almost all power. then It went to a complete no start situation so I rigged a HP Oil guage and found no pressure at while trying to start with a full reservior. I suspected the IPR was damaged more than likely from when I tried to clean it out So I went to the local ford dealership to get a quote of $500 something, International cut the price to $194. I remembered a PSD in the junkyard near the house that had a cracked block from the wreck the truck was in so I decided I'd try to get the IPR out of it and see it that solved the problem so I picked up another set of o-rings from the international dealer. FWIW there is only one IPR no matter what the serial number of the engine.

Trip to the junkard gave me another IPR and I picked up the ICP just for kicks for the bargain price of $20. Went home and when the darn rain stopped I swapped out the IPR and the truck started right up. Ran with quite a good bit of white smoke (it got rid of the mosquitoes ) the smoke cleared up after quite a bit of driving (about 50) miles. EGT's returned to a normal level after the white smoke cleared up. I'm not certian what exactly caused the smoke, other than the standard answer for what causes white smoke.

In the end the answer was either the Injectors (internal parts or external o-rings) IPR (o-rings or mechanisim??) or the fuel pump. or possibly a combination of all of the above.

If the truck RUNS and has white smoke, it usually means AIR in the fuel. And since you had your fuel pump apart, and changed hoses, thats sounds reasonable.

If the truck WONT start, and has white smoke, then its usually glowplugs.

BJS thanks for Sharing... Great info......

That was good reading,glad you got your rig going.