Engine/Transmission (1998.5 - 2002) No Power - can it be the turbo?

[draymorris]

I'm back on TDR after about a year as a Chevy driver. Now I have a 99 I bought a few weeks ago. It has been abused! Along with the front end problems, the truck has a "no power problem".



I have already installed a fuel pressure guage, which made me also install a lift pump (closer to the tank of course) - and the fuel pressure is fine.



I don't see any other indications of problems that would rob my power. The turbo "sounds" fine to me.



Can the turbo go out without going out?

 

[tippytoes]

have you checked your intercooler boots/hose?



my 2000 slowly lost power, and the boost pres wasn't quite where is should be. turned out to be leaky innercooler boots. put a new set of bad boys on there, and problem was solved.





t

 

[BLMills]

I second the boost leak possibility. I replaced my dead VP44 and lift pump in September. It ran great for 2 weeks then just really seemed to not have any power and loud, like it was really working hard. Couldn't figure it out until this past weekend after I finally got around to making one of the "boost pressure tester" out of 4"to 3" black sewer pipe coupler, 3" PVC end cap and a male air hose fitting. Found two of my intercooler boots leaking under the band clamps. Adjusted, tightened down and the truck drives like new again. Best $10 I've spent in a long time. Who ever figure this DIY test out should get some kind of ingenuity award. Do a search and you should be able find a few threads. Good luck.



Gunny

 

[draymorris]

I will check into the boost this weekend. Thanks

 

[draymorris]

Update:

Just finished checking for leaks. Found a leak at the intercooler inlet. Tightened the clamp and it quit. With soap, I found a leak under the engine air heater - very small - if were a tire it would take a week to lose 10 lbs, is the best way I can explain it. Torqued the bolts - no change. All this was done at 20 PSI.

Blocked the waste gate while I was there.

Noticed oil residue in clean side of turbo.

A friend says that any play at all in the turbo blade is bad. Says he had a dump truck that the only indication was low power - no turbo noise. They sent the turbo out for repair and it fixed the problem.



Should I look in to turbo repair?

Should I consider a non - stock turbo - maybe used from a TDR member?



Thanks for the help.

 

[bmoeller]

I know the fuel pressure is OK, but how old is the fuel filter?

How much boost are you making?

Be careful about getting used parts. TDR members or not. I'm 1 for 2 on getting a good one from 2 different TDR members. The guy that sent me the bad one dropped off of the face of the planet. The bearings were junk. Compressor wheel was touching the housing.

Some side to side shaft movement is OK. It is oil clearance for the bearings. If there is enough for the wheel(s) to touch the housing, then it needs rebuilt.

For a Holset, there shouldn't be any noticeable end play. The aftermarket turbos allow for more end play clearance.

How much oil in the compressor housing? If it just light residue, there won't be problem necessarily. A tiny bit is OK. Just don't want a puddle, or more than just a slight residue. Too much, and the engine could run away on you.

 

[draymorris]

Oil in the housing is just a residue but more than I expected. It is gummy. No puddling.

I can't get this truck to smoke for any reason - lugging or rompin on it - I mean none!

Don't have my guages on yet - maybe before the week is over. I have a temp fuel guage so I am sure that I have enough fuel - or at least I believe I do.



New theory - plugged up exhuast slowing turbo - reducing boost.



Play in the turbo does not seem excessive to me - oil bearings need some gap. Blades do not touch turbo housing.



I have also been told of a man who changed his turbo for similar reasons on a 2nd gen 12 valve and he gained his power back.



Thanks again. Keep the replies coming.

 

[PC12Driver]

If this truck is stock you'd have a hard time getting it to smoke, so don't use that as much of a guide. Your turbo is probably fine. A little play is normal, as is a little oil. As long as the blades aren't scraping. Maybe check your wastegate to make sure it isn't stuck open or the actuator rod isn't binding. A plugged exhaust is VERY unlikely, unless there is an actual crease in it.



Without pyro numbers I'm only guessing, but I'd look at the MAP sensor. If it doesn't "see" boost, the ECM won't increase the fueling rate (this is to prevent smoke and high egts off-idle). And a faulty MAP sensor will only throw a code if its voltages are outside of the normal range. It could be stuck reporting a low pressure and still be within the "normal" range. So you could have a bad MAP reporting low boost numbers, preventing the ECM from reaching 100% fueling.



But without a boost gauge or a pyro, I'm only guessing. Airflow restrictions will have high egts and will probably cause smoke. Fueling restrictions would give low egts and no smoke. Remember, diesels get power from fuel, not boost.

 

[draymorris]

Need more help.

Now I have had a fuel injection shop tell me that I need 15 to 18 PSI for my VP44 to function properly.

He also said that if the turbo had a problem, the truck would smoke.

He also said that I needed to check my MAP sensor.



Questions:

What is the most logical way for me to read my MAP sensor?

What electric after market pump will acheive 15 to 18 PSI without spending $500.

Does anybody want to buy a 99 dodge or trade for a 2nd gen 12 valve?



It seems that by the time I get this truck running and driving right I will have 1500 in the steering, 1200 in a VP44, upto 500 for something like a fass, maybe a MAP sensor, maybe a small box to get nice power. New tires after the front end- where will it end?



Any input is appreciated.

 

[SnoKing]

Here is another little thing for everyone to check. Lift up on the throttle pedal and see how much free play there is there. If the pedal moves more than a 1/4 to 1/2 inch, then take some split fishing sinkers and sqweeze them on the cable to take up some of the slack. I was only getting about 3/4 to 7/8 full throttle. I noticed this because the cruise control had more power on hills then my right foot when towing the trailer.



Be sure to check this before dyno'ng a rig. My numbers where a little low on the dyno, and rightly so if you can not get full throttle.



SNOKING

 

[PC12Driver]

What is the most logical way for me to read my MAP sensor?

An OBD data reader would be easiest, if you have access to one. Otherwise run a pair of leads from it to a multimeter in the cab and check voltage vs. boost. Or take it out and make a test manifold out of PVC tubing or something similar (easy on the pressure). Do a search and you should be able to come up with the proper voltages or resistance.

Now I have had a fuel injection shop tell me that I need 15 to 18 PSI for my VP44 to function properly.

They're high. My stock LP supports 450hp and doesn't drop below 9 psi at full throttle (about 14 psi at idle). Anything above 6psi is considered "safe" by most. The key is to have surplus fuel. As long as you have something over 6 psi, look elsewhere for your problem.

 

[JTruelove]

I took min eto Lone Star Motorsports in Midllothian. Talk to Hal 214-499-2028.

 

[draymorris]

PC12 -

Thanks. We must have been replying at the same time according to the clock. Your info sounds very similar to what I was told by the injection service, except you have more explanation.



Snoking - I have about an inch of slack cable. Took up about 3/8 of it and cant feel a change. Should I take more slack.



Is there a box that I should look at buying to read codes and the MAP sensor?



Thanks

 

[draymorris]

Well, yall got me again. Replies before I can finish a reply.

Thanks again

 

[bmoeller]

Some auto parts stores like Autozone, NAPA, Carquest and sometimes WalMart sells code scanners. Make sure to read on the package to see if it will read a live data feed. That way you can see what is happening with the engine running or driving down the road.

The one I have will read live data. IIRC, it cost ~$170. Sometimes Autozone will let you use a scanner for free, or for a small refundable fee when you return the scanner.

Too bad I'm not down in San Antone visiting my brother. I'd bring the scanner along and check it out for ya, at least assuming you still weren't 6hrs away. TX is a BIG state.

 

[draymorris]

bmoeller

Thanks but I am about 5 hrs away from San Antonio. I think I located a scanner. Hopefully know more within the hour.

Are the MAP sensors a dealer only item?

I located one for $97 at a local dealer - is that normal price?



Thanks again

 

[aircop]

Make sure it has a clean air filter in it, because if its pluged it will make no power.

 

[PC12Driver]

I located one for $97 at a local dealer - is that normal price?

Thanks again

I'd try to track one down from a Cummins dealer. I picked up one from Hoesli Diesel for about $50.

 

[draymorris]

Thanks again, to everyone trying to help me.

Here's the latest:

Hooked up to a Snap On scanner - MAP shows 0 psi, rev it a little gets 7 psi - rev it hard gets 15 psi - nothing in between 15 - 7 - 0. I think the scanner in reading to slow.

I feel that this shows the sensor is working - or at least working some. How can I be sure without having prior experience with the scanner.

Should I just replace the MAP? If I can find one for $50 I probably will ASAP.



I never could find a test procedure for the MAP sensor in the thread searches I did last night. I anyone can direct me to the procedure, I would give it a try.



New symptoms:

I drove about 150 miles today in a mix of hwy and in-town driving. Seems that the more I drive the worse the idle got. In the mornings, the engine idle is smooth, the warmer the engine - the worse the idle.

The idle is not too bad, just seems like a gasser with an old carburator on it - kind of a light sputter in no specific pattern.



I feel like I am headed toward an new VP44 fast - ouch!



I also talked to a performance shop yesterday. They feel that I need a min of 12 psi lift fuel at idle. The man at the injector service who claims to be one of the five in TX that can rebuild the VP44 ( I am assuming he has the test stand) I need a min of 14 at idle and min of 9 at any time. He also told me to replace my lift pump with a factory lift pump, but from what I have heard, factory pumps are mounted in the wrong location(which I do believe), they are overpriced Carter pumps(which I do believe because it looks just like the Carter I mounted on the frame a few weeks ago) and they won't do 14 and 9 WOT even new(I don't have enough experience to believe this or not).



I would like to make a few points - I don't understand 2 things about this lift pump scenarios and discussions.

1. I know this has probably been one of the most discussed issues, and I have read many threads about LP's - I mean nothing offensive to anyone - Why does the VP44 need anything more than positive pressure? I understand that in a 2 stage pump system, inlet pressure at the second stage can help determine the final pressure. But here we're talking about a pump that takes, let's say 12 psi and compresses it well over 10,000 psi. I understand that air/cavitation is a very bad thing - thus the FASS type systems were introduced. But if you maintain 1 psi of non-aerated fuel on the inlet, how does a fuel starvation occur. If there was a need for more, would the pressure not show a vacuum? Wouldn't the pump have to attempt to take more than you were giving it, which means you should see zero on the guage?



2. Why is it that the number for minimum lift pressure varies from person to person. Is there a Bosch (not Cummins, not Dodge) spec, in writing anywhere. A little engeering data would also be helpful in explaining the need for ?? psi. If the pump had to have ??psi, why didn't Bosch build in a piggy-back pumps to insure a certain inlet pressure.



Again, no offense intended to anyone.

 

[PC12Driver]

If you're having idling problems I think that would pretty much eliminate the MAP (or any of the sensors for that matter) and point to the VP44. I don't suppose the scanner pulled any codes?



The surplus fuel is for cooling. The extra fuel passing through the VP44 keeps its internal electronics cool. Most of the fuel supplied by the lift pump is bypassed and returned to the fuel tank, effectively turning the tank into a heat sink. So if you don't have the surplus fuel, the guts of the VP44 will overheat and fail. It's not so much the PSI, but the extra flow that results from having surplus PSI.



As far as the "correct" pressure, it all depends on who's doing the talking at the time. If you do a search you'll find all sorts of answers. Basically, high pressures (~18+psi) may cause hard starting and could possibly cause premature wear to the internal valving, and low pressures (~6 psi or less) won't supply the surplus "cooling" fuel the VP44 and may cause excessive wear/overheat. I think about 15 psi at idle is the goal for most with a psi or two in either direction. The key is not going below 5-6 psi under load.



And of course, pressures are sort of subjective, since they can vary due to friction loss and the relationship of the placement of the pump and pressure sensor in the fuel system. But I think the numbers I listed above are safe for the majority of our fuel system layouts and needs.