I think I have a stuck injector. Look at the info and let me know what you think. This is for the truck in my signature below.

Owned truck since new, drive for best milage occasionally open it up.
at idle, tach needle never stayed steady always had a little blip in it.
No trouble codes are in the computer.
60,000 miles my mpg dropped from 21 to 17 during a road trip.
truck would then on occasion puff out smoke on startup, (always starts good and quick,even to today).
could hear the turbo progressively spool at lower rpm than normal.
70,000 miles bought smarty, and gauges (egt, boost, fuel pressure).
fuel pressure was bad, so I put on factory replacement lift pump.
milage got better with smarty timing advance, not quite back to normal though.
checked for boot leaks on intercooler, all is ok.
put new MBRP 4" exhaust on and tip quickly got covered with heavy wet soot.
fuel pressure was still low with new pump, installed airdog.
turbo started running boost at 55mph on flat and level road (never did this before).
Fuel pressure would occasionaly twitch (mechanical gauge).
fuel pressure then went haywire, 3 to 15 back and forth, boost building almost continously, horible milage, egt's climbing higher than ever have (normally always under 1100, now will shoot towards 1300).
fuel tank is full, so its not sucking air.

I think I have a stuck injector (or more) and have ordered a new set of Mach4 injectors and have parked it. It seems like there is raw fuel being dumped into the engine (i assume from a bad injector) Please let me know what everyone thinks, does this seem like I am looking in the right dirrection? Thanks.

 

if its making oil you could have a leak in one of the injector connecting tubes also my 01 makes about 5psi boost at 55 on flat ground. also check the map sensor .all wire connections and grounds worst case VP. not all of them will throw a code some have had them go dead with out ever a code

 

guess I missed some info,
IAT and map were changed when I replaced the fuel pump.
oil level does not climb between changes.
I have 3.55 gears and when it was new you wouldnt hear the turbo spool until 1700 to 2000 rpm. and that rpm kept droping after 60,000 miles until I am where I am now.

 

when it starts to puff smoke at startup and mpgs start to decline its a sure sign of a dying vp, but it could live that way for a few years. if your oil level was rising then u could have a bad injector, or cross tube.imo i would sell the living vp now for some $$ to offset the cost of a new one.

 

I actually put on about 30,000 miles since it started to puff smoke on startup(89,000 on odometer now). Like everyone with a 24v engine I know a new vp is in my future and I am watching for the signs. Tap of the key is all it ever takes to start truck (warm or cold). I cant see a bad VP adding extra fuel, but bad timing could cause the fuel not to have time burn. Can a bad VP keep running good but mess up the timing?
One more sympton I forgot to mention.
when I installed the smarty, the 3 cylinder high idle came with it.
3 cyl idle worked good for a while.
but when the fuel pressure went haywire and the 3 cylinder high idle kicked in, the engine would start to knock like crazy. If you touched the throtle and kicked it out everything smoothed out and quieted down. this was not normal 3cyl high idle noise (i know what that sounds like), it sounded more like pre ignition or rod knock style noise.

 

Who's going to buy a used VP-44?
Sorry, just struck me as very funny to even think someone would consider buying one.

RJ

 

yes thats what happens slip in timing..Rowj ive seen plenty on ebay...and here in the classifieds..even as a core its worth $300

 

UBEAST- you can try to put some TCW3 2 stroke oil into the fuel- IMO a mixture of approx 500-800 parts diesel to one part TCW3 gives good results.

The tach doing a little vibrating without the engine changing sound seems to be a slight problem on some of the 24Vs- when I changed the instrument cluster it went away on one that had the problem (in that case the cluster had other damage that made it necessary to go for a new one)

The higher boost comes from the higher EGTs, and they usually come from retarded injection timing. The cold weather warmup uses rather late timing to get the temps up quickly, and also to run EGTs high enough to avoid buildup on the exhaust valves.
With the airdog's pressure fluctuations I'd look into a plugged suction line from the tank or a plugged prefilter (I don't know the airdog system..) and for good electric contact on it's supply.
The other thing that made me mad with a customer's truck that had almost the same symptoms were bad engine grounds and corrosion in the ECM connector.
Cleaned up and the truck had it's fuel mileage back.

HTH

AlpineRAM

 

If he buys a new one, What will he use for a core? I couldn't look a guy in the eye and say, ya it's a good one.

 

AlpineRAM,
thanks for the good suggestions. I actually have been running a little two stroke oil for the last 5 fill ups. That's good to know about the tach, it always sounded like it idled even so I didnt really worry about it. I wonder if my fuel may have gelled up on me, It warmed up to 45 f (had been in the 20s) so I started it up and it doesnt have that eratic drop any more. When I put the Jake Brake on (6 months ago)I had to hook a ground on to the engine and the ground wire was like new, no corosion. I also had to hook a pin into the computer and had the connector off for that and it was also clean with no corosion (i think it was also covered with dielectric grease).

 

I think you made a fine investment in Mach 4s but I also think that, while that will make the truck better overall, the main issue is the VP.

 

I hope I made a good choice. How long has it taken other people to get their f1 Mach injectors? When I ordered mine from performancedieselwarehouse 23 days ago they said f1 was backed up and it may take a couple weeks and they would give me a date that they will ship, then no reply. They did charge my credit card the second I ordered them. I waited a week and emailed them, They keep telling me they will check and let me know when they should ship, and then I hear nothing from them. I wait another week and email them again, last email they acted annoyed that I would even ask (but still gave me no info). If it takes too long for me to get them, I think I may loose any protection offered by using a credit card for payment.

 

I would call other F-1 dealers to see who has what you want, in stock! If you find them...cancel your order. I have heard F-1 is backed up a bit but your experience is, IMO, unacceptable.
I have bgt two sets of Mach's, over the last 4 yrs, from Rip at Source Automotive and both were in stock.
http://www.f1diesel.com/contacts.html

RJ

 

I took the advice and it looks like I am SOL . No one has any and they said they got a email saying F1 wouldn't be takeing orders for a couple weeks. Bob W said he would check on my order since Cory at PDW never gave me any info. Cory said Don called him mad and because of that my order is now canceled. All I wanted to do was spend lots of money on some shiney new parts. I guess after a month waiting, I will have to end up cleaning up the stock injectors and have them tested. The wife is getting sick of driving me to work.