Welcome to www.cartaste.com !!!

CAT 3406E low boost has issues

Question:
Hi all
HELP!!!???
We have a 99 International with a 3406E engine, 550 hp. It's giving us some issues... low boost pressure, low power, doesn't seem to accelerate well, can't tell the fuel pressure but CAT set the injectoers and valves a few days ago, said all was reading fine, injectors were all good, boost was good, 1500 miles later it starts acting up again. He checked it all over, sensors etc. because it seemed like something loose in wiring as it was cutting in and out. Another dealership and they found high voltage code for sensor so they replace boost pressure sensor, and then it seemed fine. 10 miles down the road and Hubby said it started acting out again, wouldn't build past 15 lbs, replaced the fuel filter, that helped, then it got worse again. No boost better than 8 or 10 lbs and she'll barely haul herself much less a load. It's not showing any codes. It has a new turbo, new air to air, new throttle position sensor.... hmm among other stuff. Anyone have any ideas for me??
Crimson, one slightly desperate owner ops wife!!!!!

Answer:

Oh, and I forgot that my husband shut down for a while, and when he started running again, it seemed to work better for a while (until engine got warmed up??). Then boost pressure dropped again. Comes up a bit now and again, was up to 20 lbs for a bit but dropped back off.
This car's gonna make him bald.
Crimson

Answer:

It is old enough that it may have failing fuel lines. Bits of rubber from
the lines either fold over or stack up in the fittings. The inlet to the filter
is usually easy to disconnect to look for black bits and apply air back to the
tank to see that the pickup is clear. If it was parked for a while a check for
water in the bottom of the tank is another thing to do, there may be growth
at the top of the water. A siphon will remove any water and most other dirt
from the bottom of the tank
dl
It takes fuel to make boost.

Answer:

We are thinking it's not a sensor or wiring issue, more and more looking like fuel for sure. It all started the day he took it to Cat, he had repaired a wire at the boost sensor because it was chafed through. Which is why they've all benn concentrating on the boost sensor I guess. It almost acts like something is limiting or derating the engine? Cat is going to check it with the computer this morning....
3rd shop in a week, at least this guy wouldn't charge us yesterday and I quote him "I didn't fix anything yet" , and he got Cat to agree to put it on the computer for free.
Will definitely tell my huband when he gets up in a bit. Thats something thats simple for us to do..
Thanks
Crimson

Answer:

hmmm so today Cat put car on the computer, huge printout with no answers. They rechecked injectors. All good there. 4 shops in a week and every one of them are scratching their heads. Back to the local Cat man....... Pressure checked at the turbo, turbo is all good, air checked, no leaks all is good there. They checked the fuel pressure and the transfer pump, - all good there, checked fuel lines ....no leaks or anything ..... all good there... there are no fluids where there shouldn't be..... they swapped out some sensors.. nothing helped. Even swapped out the ECM just to see. No change.
Cat dealer wants to put it on the dyno. We already know it won't pull sh#t, hauling empty flatbed too much for her. We know that will be waste of time & money and they'll want to put all new injectors in it because they don't know what else to do.
We can't figure out what it could be. Really tearing our hair out on this one.... poor Kitty is minus balls and engine runs smooth. Any help would be appreciated.... please?
been a long week.
Crimson

Answer:

The formula is simple,
No fuel = no power
No boost = no fuel to make power, once you get past the basic mechanical inspection.
If you don't want to take the fuel lines apart to check, then hang a 5 gallon fuel can on the mirror
bracket and dip a short piece of hose from the can to the pump and one back for the return line.
Dad always kept a couple of 5's for people that tried to ween their equipment, since it was handy
it got used for other stuff, like troubleshooting. With the current cost at the shops it is cheaper to
buy the stuff and throw it away than to pay for people to use their particular hammer. When your tool is
a hammer everything seems to resemble a nail. The mechanic spent $5-10k on a diagnostic tool so
it is the first one a lot of them pull out of the box, thats the way the tool is justified
A wire was repaired and the ECM now tests as a happy camper - next problem.
If it has 1 or more moving parts it will need repair.
A car needs one trip to the dyno - when you buy it, after that it becomes a step in the disagreement if
the repair is not correct
If it is the fuel lines blowing air backwards into the tank will either stop the car or it will run well for
a little while, this is not a popular test because the fuel has to be reprimed and the problem will
come back
My sister spent $1200 on a sensor in the distributer that cost about $50 be cause the first 'mechanic' with
ten years operating a shop with 5 employes dropped the distributer in with the rotor pointed to #1 terminal,
the cam gears rotated it out of register and it ran rotten. His diagnosis ? ECM. Second opinion - same.
Off to a shop with over 250 years of mechanic experience on the floor - ECM. Sent the ECM infor rehab and
the rebuilder sent it back with a note and a bill for freight - this ECM is not broken. About 3 days later I came
through and we went and ransomed the Jeep and drug it home, I looked at the bills and lifted the dist cap
to check rotor registration and it was one cog off. They are not supposed to run when assembled this way
is the only excuse that I can imagine for the 3 shops that worked on the Jeep.
dl

Answer:

Yep know it's a fuel issue-- only thing left in the equation LOL We even swapped out the ECM just to be sure.... finally my father looked up and saw the fuel heater/water seperator..... and wondered if it had a filter in it. Now dear hubby drains it but has never opened it... it has a "self- cleaning" filter in it, that is black and gunky and definitely not clean. Searched for a new filter and have to order one. So we cleaned it and put it back in. car ran crappy to my Dad's farm 3 miles down the road, they repaired a section of exhaust, then when he drove 3 miles back up here it ran fine. Boosting 25 lbs, little lower than that when he put a load to it.....Took it for a drive again, 3 miles down to the farm and it worked like crap. Drove back up the road.... and it ran fine, boost pressure up where it should be. Today picked up his new load and it's back to working like crap, boost down to 10 lbs and no pull.... So we are thinking has to be a fuel line collapsing or sucking air .... or he got a nasty batch of fuel, hmm have heard before of guys hauling bunker crude and forgetting to wash the trailer down before loading diesel etc. If that was the case would it take a while to purge the system of any contaminents?
We have only had this car about 9 months. The more we look, the more we find multiple little things that need repaired before they become huge things.... and we've already replaced the turbo, air to air, oil cooler, had the rad repared, replaced an air tank and lines, exhaust parts, broken spring, new U bolts, new throttle pos sensor, new boost pressure sensor, ....among lots of other minor things.
I appreciate all the input -- definitely getting alot of great info and advice!!!!
Crimson, the slowly-going-bald carer's wife....

Answer:

Well got the Cat running better, got it dyno'ed and found out that car was putting 575 hp to the crank but only 225 hp to the ground.
Somehow they tested fuel consumption and most of the fuel was going back the return line to the tanks, no wonder the fuel mileage was going UP.. like a 2 mpg increase?
Cat says 6 new injectors. Of course. But they wanted $7000 to do the injectors, and they were all booked for 3 weeks.
Weren't gonna let them do it anyway.
Off to our local mechanic who looks at all the printuts and says yeah we better do the injectors .... and gets it done for us for $3000 . One injector had broken spring .... and knowing the guy we bought the car from, and the guy who owned it orinally..... the injectors have NEVER been done. .
So car is running better now, boosting 22 lbs empty and has power.
Crimson Glory

Answer:

Its called MAINTENANCE , have it hooked up for the ECM to be checked on a regular basis then need to get it checked up on the DYNO a little more often than when you buy it or its next to DEAD.

Answer:

We know about MAINTAINENCE. This is our 5th car. We have only had this car a year(next month) and have come to the conclusion the previous owner didn't believe in MAINTAINENCE.
ECM has been hooked up and checked a half a dozen times since we bought it. The issue was the car was not showing any other symptoms of bad injectors, which left us scratching our heads. Along with the 4 shops that looked at it, 2 of them Cat dealership/shops.
Thanx

Answer:

GeeWiz dont get so SHORT TEMPERED , My POST was GENERALIZED about how many fail to get PROPER DIAGNOSTICS until its on its last legs, and was not totally directed at you.
Who cares if you have owned 5 cars or 500 cars , its this car you were having problems with and it seems that you found a shop that finally did a correct diagnostics , now next time its acting up you know where to go get it checked and then repaired someplace else for some $ savings which is smart business practice.

Answer:

I wasn't being short tempered at all, just emphasizing the maintainance part. The car had been on proper diagnostic equipment repeatedly and no one could figure it out.
My post was just to log what had resolved our issue.
I am sorry if I seem to be touchy on the maintainance issue...we are constantly maintaining our rig. And your post did not seem to be a general one.
Crimson

Answer:

The phrase I like that sums up these type of issues " keep it simple, stupid " I have spent 25 yrs in the euro sportscar repair, and I can say that when ever I have faced a problems that initailly customers suspect to be ECU / sensors etc, more often than not its just a basic mech' problem. Their a lot to be said for running pre common rail / mechanical diesels, except for mgp !
Copyright © 2007 - 2011 www.cartaste.com