View Full Version : Losing power in my SD33t... and other problems

07-24-2009, 12:58 PM
Just posted this in the tech. help section... sorry, its been a while and I never noticed the diesel tech forum :p, so here goes...

I recently got done re-building a lot of my 1980 terra and have been using it as a daily driver for about 2 weeks now. In the last few days I have noticed that I have been using a lot more fuel driving around town, I checked the turbo and it seems like the intake is sucking (excuse the pun :p) a lot less than it was when I first started driving it around.

Also, I had to replace the alternator with an after-market one, and in-order to get it to start charging I have to "rev the engine every time I start the car to excite the alternator", said the guy at the alternator/starter shop. Being new to diesel engines... I don't think thats very good for it. If I dont rev the engine way up, it runs really smooth... but I kill my battery; when I do rev it way up, the engine idols really really heavy and all sorts of other sounds start going, yet it still runs fine.

Any advice that anyone can give me would be greatly appreciated...

07-24-2009, 03:16 PM
What all have you done to it that constitutes a "rebuild" on the engine? I had mine completely rebuilt (new pistons, sleeves, bearings, gaskets, and new head) and it ran really rough for a couple hundred miles until it finally got used to running again (and I only got about 15-18 mpg for the first 800 miles). As far as the intake not sucking enough air, you might want to check your turbo and see if it's internal bearings are starting to go out. If you want, you can also take off the air filter and stick your hand over the intake while the engine is running. It should suck your hand down and start to stall out the engine if you don't pull away fast enough. If it doesn't start to stall out, you have leaks in your system and the air isn't coming from the intake like it's supposed to be. And for the alternator, that just sounds absurd. It should start charging the system as soon as you start the engine regardless of the engine RPM's. And yes, sudden changes in RPM's on diesels are never an extremely good idea. They're designed to run constantly at a given speed and not change from that for them to put out peak performance. I'd say take the alternator in for a bench check... there might be bad internals in it even if it is "new".

07-24-2009, 09:20 PM
lol, i guess i should clarify a little. I re-built a lot of stuff around the engine. when I got the truck i think it has less than 100k on it... i want to say around 85k... so for a diesel it should be basically new, minus the sitting around for a very long time. I did some general maintnence on the motor, flushed all the fluids and changed out some sensors and thermostat and such, but nothing big.

The turbo is still sucking air, just not nearly as strong as when i first got it running, and it did stall out when i put my hand over it. i checked the filter and such and it looked clean, or atleast almost as clean as the new ones i have sitting around; so i guess one of these weekends i should take a look at the bearings... and that alternator... thanks!

07-25-2009, 10:59 AM
No problem. And unfortunately, low mileage doesn't ALWAYS mean good engine. When I got mine it had around 110K on it, but didn't run worth a crap. Turns out the P.O. had run it hot and not let it cool down properly, and the #4 cylinder had over-expanded and almost seized up, and he had cracked the head in 8 different places. Also, you might want to check your injectors if the engine had been sitting for a while before you got it; mine sat for 6 years and all 6 of my injectors were shot.

08-27-2009, 04:16 PM
you can also check timing. it is very possable that it could have sliped

09-17-2009, 11:53 PM
Good advice!
What has happened on this? Any updates?

I would guess you have a self exciter (Also called a one-wire) alternator. They don't charge until they sense a little current out put. This is from residual magnetism so it will vary from alternator to alternator. I have two of the same model at home and one will almost start charging when I start the truck. The other has to hit about 1200 or 1500 rpm before it starts. I don't idle my engine vary long after start up so I just head down the road and the alternator will kick in. Once it is charging it should stay 'on' until you shut off the engine. Then the process starts all over again.

12-03-2009, 05:28 PM
If you're wondering about turbo health, try removing the intake ducting and try to wiggle the turbo impeller with your hand. If the thing is real shot, you can feel it move by hand. Mine did with only 89,000 original miles and I needed a cartridge (rebuild). The PO didn't observe proper cool down protocol after pulling the So Cal mountains where he lived.
You could always pull the injectors and have them tested by a diesel shop for pop pressure / spray pattern etc... be advised you'll want to replace the copper washers under the injectors when you do this and sometimes they're a bit stuck. I used an easy out on a small slide hammer on mine.

Good luck and remember that you can probably find a free replacement Scout on Craig's list if this one doesn't work out for you.

12-13-2009, 08:14 PM
Dear Rakesh,

This seems to be little bit critical project I can help you out in designing the project but not coding the project, BTW you forgot to mention that about the ecube algol how tha works as and what is o/p that it gives.


02-19-2010, 06:15 PM
I havent noticed any power loss with my car. But not everyone has the same problems. One of my problems was a blown ecu

You should try talking to Zuber Speed, he seems to know his stuff about the chipping

06-29-2010, 02:14 AM
OK I have the solution. You need to disable McAfee from protecting your computer. Once you do this you can re-install the game and play. This is a quick fix but you will not be protected any more. McAfee will need to correct this at some point.
Good Luck,