Low Power, Fuel Mileage Drop - Help Please
 

I have a 92 Dodge D250 with no modifications other than an Air Dog Fuel Pump and all of a sudden I have no power and fuel mileage went from 19-20 miles to the gallon to 8 miles to the gallon.....I have to put the pedal to the floor just to get up a slight incline. Does this sound like a Turbocharger? Not sure what would effect me so dramatically like this..

If it is a Turbo and I need to change, any recommendations for replacement? Can I troubleshoot myself? :humm:

What's the engine doing (or not, as the case may be) when it is floored going up a slight incline? Miss, sputtering? Smoke? What color? Unusual noises or smells?

Gonna need alot more information to figure this out...

Clouds of black smoke.....even on a straight level road I still have some smoke with no load...

check your air filter

So it's getting plenty of fuel, but not enough air - major boost leak? Torn intercooler connector?

Don't push it too hard like that - EGT will be through the roof.

Air Filter
 

Replaced Air and Fuel Filters when it started....

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No turn connectors, don't know about a boost leak but is the turbo is no working at all that would be the same? Don't know what a "EGT" is but I was on a trip back to my home and had to drive 8 hours straight in this condition...couldn't get over 65 miles an hour on the level, about 55 mph on a grade blowing black smoke the whole time...

Well, yeah - if there's no boost to leak in the first place, that would give pretty much the same result.

Have you actually inspected the turbo itself yet?

EGT=exhaust gas temperature, I agree on a possible boost leak. Look all the rubber boots over real good and check to make sure none look as if they have moved on the piping I"ve seen the clamps fail. If there are no obvious leaks do an either check. Why do you suspect the turbo, is it making extra noise or some squealing sound which could also be a boost leak? Most turbo failures on stockish engines are oil leaks and not complete turbo failure. :rocking:Rocky

i agree with them it has to be a boost leak the stock boots tend to dry and split

Boost
 

I can't find any evidence of a boost leak....I took the hose off of the intake and revved the engine and the pressure was enough it was hard to put my hand over it.....not sure how I would actually check the boost since it is a 2" line. Not sure how I would take a pressure reading to get exact measurements.??

Checked all of the boots (at Turbo, both sides of Radiator and at the intake).

Basically my theory that the turbo might be bad seemed to be false so I have no idea what to check next.

There is a rubber gasket between the compressor of the turbo and the metal neck that mounts to the first boot you can check there you would have to take that clamp off. Have you also just to see, take the air box hose loose from the turbo and look at the comppressor wheel? See if it spins freely by hand. I have had one build up rust on the exhaust side and just not turn had to take the turbo apart and free the exhaust wheel to get it to work.

Turbo Check
 

The turbo was free and smooth, had taken the air box hose off just an hour ago.....will check the rubber gasket at the compressor...

When you set up a boost gauge where does it get connected at or how do you set it up to take a pressure reading?

With the eigine at idle speed and the intake piping to the air cleaner all in place, take a can of starting fluid (either) and spray all the intake piping, intercooler and intake side of the engine including the plates in the head where the last aluminum cast elbow is, if there is a leak the engine will rev due to the either.:rocking:Rocky

There is a port on the manifold right below the intake neck its hard to see but look there its probably in the sticky note about hooking up a boost guage.

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1arock has a good method there it will tell you where its at

ether test
 

I wondered what you meant about the ether before, now it makes sense, thanks, will have to hit the store for a can....thanks

Is your air dog working correctly? low fuel pressure (flow) can cause this. hopefully you have not hurt the engine driving it so far smoking like that. possible to burn a valve or piston like that. A way to check that is a compression test. First check your fuel pressure, flow and then check your boost. on a stock truck I believe 15 to 20psi. is pretty norm... Well have to be under load to show any boost.

Fuel Pressure
 

I did finally figure out a way to test the fuel pressure, I was at 15lbs so I think it was OK....Don't get me started on the Air Dog....worst purchase of my life.:td: All I could do was hold a rubber hose connected to the fuel pressure gauge at the output line off of the injector pump as tight as I could because there is no way to install a fuel pressure gauge and/or install a fitting to even measure the fuel pressure...

I hope you are not right but after the trip I started the truck for the first time this morning... At first it didn't want to start at all and then I had a weird clacking or noise I couldn't figure out that was not there before. That's all I need now.

Low Power, Fuel Mileage Drop - Help Please
 

Could have blown a tip off of an injector. Poor atomization will cause low power while pouring black smoke. Ether sounds like a good idea but from my experience even at idle if you take the plug out of the head air flows from the hole, meaning the head and piping is all under positive pressure at all times. Kind of hard to pull ether thru a hole when the system doesn't ever run under a vacuum. It'd have to be a pretty substantial hole for it to work as intended. Lots if soapy water.


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a good idea but from my experience even at idle if you take the plug out of the head air flows from the hole, meaning the head and piping is all under positive pressure at all times. Kind of hard to pull ether thru a hole when the system doesn't ever run under a vacuum
Ok pull the clamp from the turbo outlet and turn the elbow away from it first, it will work I've done it.:rocking:Rocky

Diesels don't make vacuum. That's why the older ones have vacuum pumps and the newer ones are all hydraulic/electric.

:argh: WHAT lol All 4 stroke piston engines create vacuum. diesels may not create much vacuum unlike a gas engines that create more vacuum. The only reason for the vacuum pump is to supply enough vacuum for brakes and vent doors in the heat and ac system.

OK then, maybe you'd care to explain how an AD working not working "correctly," supplying "low fuel pressure" will cause excessive amounts of black smoke:

Low Power, Fuel Mileage Drop - Help Please
 

With no throttle plates to restrict air flow there's no way to create vacuum in a diesel, no point in having throttle plates when they'd serve no purpose in a diesel. Diesels with out a turbo will create areas of lower pressure than atmosphere for atmospheric pressure to rush into the cylinder but still not technically a vacuum, diesels with a turbo create pressure greater than atmospheric even at idle... Otherwise you are correct in the aspect that with out a pump diesels wouldn't stand a chance at producing enough vacuum for any type of vacuum actuation.


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If you not getting correct amount of fuel to the injector pump it can cause the injector pump to also not have enough fuel pressure to atomize the fuel. Injector will dribble and cause black smoke. And lose of power due to not burning all the fuel.

Nice Try, No Cigar:
 

The mechanically popped injectors in these trucks go at around 8,500psi, IIRC. Whether or not fuel atomizes is all up to the injector after that. That's why I was liking the broken tip idea, but nothing to do with fuel supply or IP, no matter how you slice it.

Low Power, Fuel Mileage Drop - Help Please
 

I think they're a little lower than 8500. I think the 2nd gens are around 8800. Low injector pump fuel supply pressure (especially in the VE) will cause delayed injection or basically retarded injection timing. If pop pressure is 6500 psi that injector isn't going to open until pressure peaks at around 6600. Simply; injector will atomize like clock work. Depending on supply pressure Pump may not deliver enough fuel to rapidly build line pressure and inject fuel as intended, when intended... Which will result in white smoke (unburnt fuel) or in essence severely retarded timing. Pair that with the VE which has a dynamic advance reliant on fuel pressure, no matter how low your fuel pressure you're going to end up with white smoke before black and more than likely popping from the delayed injection.


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Exactly
 

Thanks for that. Sometines I just don't verbalize properly. :c:

you 2 can have a pissing contest all you want. my lift pump went out and blow BLACK smoke low rpm's. white smoke at HIGH 3000 rpm's. and lost power. And retarded time well cause black smoke, high egt's, and high boost. Don't believe me retard your pump 1/4 or more and see what happens. It will even smoke at idle. retarded that far. And pop pressure is around 3550 psi for injectors.

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And back to the question asked.

"Poor performance, black smoke or low power. Improper fuel, Air in fuel system, intercooler internally blocked or leaking, Restricted or blocked fuel injectorlines, Incorrect injection pump timing, Restricted or damaged injector nozzle, Clogged or restricted air filter, Air fuel control tube leaking or broken, Low manifold pressure, Injector sequence does not correspond with firing order, Lower or uneven engine compression, Injection pump to engine timing, Fuel injection pump malfunction or not adjustable"

Funny You Didn't Mention That Before...
 

So it's really a timing issue, then?

http://dilbert.com/dyn/str_strip/000...rip.sunday.gif

Guessing's OK for the weird stuff, but A/F/Smoke is pretty basic. That's alot of guesses you got there! :rolleyes2:

That guessing you call it is from the Chrysler service manual smartass.

Well, That Really Narrows It Down, Then!
 

Yeah, I'm guessing maybe somebody swapped the injector lines around while it was parked at the Dairy Queen. Yeah, that sounds like a good possibility. :ha:

Reading (or cutting and pasting from) a service manual and troubleshooting an engine problem are two possibly related, but quite different things.

Low Power, Fuel Mileage Drop - Help Please
 

Never tried turned it into a pissing match. Purpose of the site is to help and educate and discredit if needed .Feel privileged.... I'm paying my student loans and you're getting it for free, and don't even start the "bc I didnt go to college it must mean I don't know anything" rant. I know what I know bc I cared to listen and put my opinions aside when they were wrong... Btw he said he had 15psi fuel pressure awhile ago so arguing was pointless, was meerely trying to educate. But Black smoke high fuel pressure VS black smoke low fuel pressure, that's your statment in simple terms. If that's the case... Why pressure feed the injector pump at all... Must be the millions of dollars of diesel R&D was all wasted on nothing, bc you're pretty much saying a diesel doesn't operate the way the law of diesel physics states it should. Guess common rail technology is a bust too.


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EXACTLY! Lift pump went out... black smoke low rpms, white smoke high rpms. At high rpms your truck was using more fuel than the lift pump could supply... Sounds like low fuel pressure to me... Which you stated creating what color emissions again? White? Hmmm :humm: Btw educate me on what color smoke it is that's emitting for your pipe with 1/4" pump retard? At that level of retardation (no pun intended) Its smoking at idle bc it's unburnt fuel, injecting after peak cylinder temp ontop of decreasing burn time. That'd be RAW fuel with a white haze. Most of these old girls haze at idle even at stock timing levels lol. Just the nature of the VE. Oh and Watson... You've contradicted yourself and even proved yourself wrong with the random bits and pieces of logic intertwined with the :edit:

If anything low fuel pressure would cause retarded time with white smoke. Also if the tip was blown off an injector wouldn't that more likely cause white smoke since there is no way it could burn all the fuel being dumped into the cylinder

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Ok you have black smoke at all rpms right. Does it haze at idle if not then i would say most likely not fuel related. Im not ruling out the injector tip being blown off like tower of power said but typically an extreme excess or restriction of fuel will have whit smoke. Every time I have seen an injector tip blown off it pours white to a grayish smoke...but then again I have not seen everything.

Update on Issue
 

Just an update to what I have done so far...

Had replaced air filter and fuel filters, looked for boost but have not taken a boost reading...How much boost should I have for 1992 Dodge?

Fuel Pressure to Injector pump right at 15psi, can bring up to 20 psi if recommended...??

Removed Injectors - No Blown Tip, a little carbon on the tips of each one...Can I use a steel wool or something to clean the ends off without plugging the holes?

Have to get a compression gauge to check cylinder compression so won't have until tomorrow, couldn't find any part stores that loaned a compression gauge that went high enough for Diesel Engines. Hopefully no bad valves or pistons since I drove it so long this way....didn't have much choice at the time...

If I don't find anything after all that I may have to ask for more help....some of the troubleshooting was beyond my limited mechanical inclination at the moment.

Thanks to everyone helping so far...:hellox:

i know my truck stock only had at best 12-14 psi of boost, also you don't want the fuel pressure past where it is you could damage the injection pump

X2

Low Power, Fuel Mileage Drop - Help Please
 

You're right, was only taking the excessive black smoke into consideration at road speed, not idle. It does make sense for it to pour white smoke at idle with a blown tip. Ontop of a dead-ish cylinder. Should notice an off engine noise at the same time. All of which; hasn't been the complaint. If the injectors are out it could be worth your time to have the pop pressures tested and spray pattern observed.


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I would definitely have the injectors checked. Don't use steel wool. Use a brass brush and solvent. Steel wool could possibly mess up spray pattern

Sounds retarded. as in timing retarded. Check your regulator valve o rings in the pump. if they are blown. you will have no case pressure since regulator lets all vane pump fuel go out return = no pressure to barrel or timing piston and no advance= no power , more smoke, more EGT.

Look for any fuel on the pump, but it can also leak internally.

Fuel Pump Regulator
 

I hate to ask but is there someplace that shows how to check or test for the regulater valve o-ring? How do I know they are blown or not?