andyr354

tried to pressure test the IC tonight. Took the elbow off the turbo and rigged up a fitting in the first boost boot. Hooked up the air compressor and was putting lots of flow into it and not getting a bit of pressure. Thinking wow, must be a big hole in the IC.

Walk past the tailpipe and ....... hmmmm all the air is flowing out the tailpipe!

Am I hosed or what?

Truck didn't have any blowby last I checked. Valve way to tight, burned valve, Engine turning off in position with overlaping valves open, other???

I am gonna go take some pepto, this rig is driving me nuts!

Monty

Your fine, more than likely one of the cylinders are at overlap allowing air to come thru the open intake valve and out the open exhaust.

Bushy

I'll throw my hat in with Monty's thoughts.....use the alternator nut and rotate the engine backards a bit then re-test....remember that you will have some leakdown no matter what you do because not all valves are closed at the same time.
First make sure all your IC boots are good and the clamps tight then....
Just pressurize the sytem to about 20psi then shut off the air and initally watch the pressure gauge...if it moves downard slowly you should go hunting for the hissing sounds next.
Again you may have to rotate the engine a bit more to find the best 'closed' position for testing.

pb...

andyr354

That is what I hoped. After a drink of water I decied to go back out. Pulled the wire to the shut off solenoid and bumped it once. No more air out the pipe. I can't turn my engine with the alt. The belt just slips, even with a new belt and tensioner.

I built my rig with a regular automotive valve stem and it took a while to build pressure. I was getting a flow out the blowby I could feel and built decent pressure in a few seconds with my thumb over the hole (later with the rig running at 2K rpm there was very little flow at all)

Found one slightly loose band clamp. With it pressurized to around 15psi it took 30 seconds to get back down to zero, my guess is a good portion of it through the blowby. So it seems there is no large IC leak. With AC on this rig I can't get to the IC easily to spray soap on it (any tips?)
Maybe I will build one more plug and test the IC by itself.


Background on the reasons for this test:
Pulled through Colorado and had lots of EGT trouble. Couldn't use more than 1/2 throttle most of the time in 4th or 5th gear or let rpms get below 1800 or that was all she wrote. Egts forced me to 3rd several times where it would pull on the governor at 18psi and 1200deg constant.

Rig also just doesn't pull like it should in KS either IMHO. My 70 chevy C10 with an RV cam 350, th350, 3.42 gears will pull my 5K load easier than the dodge can.

In KS when pulling I get 18-19psi and an EGT of 1150 on a average hill, a long steeper hill will get me upto the red. This will be loosing some speed in 5th with all she's got, again pulling 5k lbs.

93 W250, BHAF, fuel screw against lock collar, AFC set to deep position, clean fuel filter, new boost boots, new o-ring and elbow at turbo, 18cm housing, getrag, 3.55 gears.

Bushy

If you're using the alternator nut to rotate the engine you want to turn in backwards...if the belt sqeals then you're tuning the wrong way bud....

pb...

flashgordon

When you egt's are high and you eng temp is high?......is your eng fan makiing noise?......is the ac or condencer full of bugs?

bgilbert

Were you spraying all boot connections, all 10mm intake cover bolts, AFC tube from head to injection pump etc etc? From the sounds of 15psi in 30 seconds, I'd say your charge air system is ok. Wannadiesel posted the spec of leakdown aways back, I don't recall, but I think you are ok.

andyr354

That was my thought, air system seems fairly tight. Guess my next low cost option on the list is to get the valves adjusted. What else should I try or look at? In my mind it is not a low pressure fuel delivery problem since I am getting high EGTs with my low power.

I don't know, maybe I am expecting to much from the oll girl. Just that soon I will be upgrading my trailer and pulling a heavier rig as well. Pulling 3-4k lbs more I will be driving 63mph in 4th on the gov with every hill.

What really burned my backside was the friend I was traveling with has a V10 excursion. Pulling 2K lbs more than me he left me miles behind in the mountains, no way I could keep up.

Andy

flashgordon

Pump timing?

andyr354

Gonna post a link to a thead on TDR:
http://www.tdr1.com/forums/showthrea...ighlight=bosch

I have had my truck do this on a hot day before. Pulled of the interstate and it would not idle. Would just die if you took your foot off the accelerator. Maybe it is that my inj pump is dying

BTW truck has 216K miles on it now.

jrussell

I bet he seemed happy tearing up those mountain roads with his V10. I bet he wasn't very happy at the next gas pump when he figured out he only got 4mpg!

andyr354

Actually he got 8mpg. I got 14.

jrussell

Sure...that's what he told you anyway!

andyr354

I am gonna try and get a valve adjustment done this weekend since I don't know when it was done last.

I talked to HTT about the turbo and they gave me a sideplay spec of no more than .015, will measure that as well. I think my turbo is quite a bit over that.

andyr354

Just for grins rigged up a psi guage to theck the lift pump. Get around 4.5psi at idle. Doing a few test runs at wot up hill never dropped below 3psi.

Good enough?

Also pulled the grille and powerwashed out the condensor/intercooler.