Ok so my 97 runs like crap, no power. sounds like it has a dead hole or two. I did a buzz test and had 2 injectors that didn't sound as strong as the other 6. I did however neglect to do a cylinder contribution test.

After the buzz test I ordered 2 reman injectors. I hooked the scan tool back up after the valve covers were off to make sure which two to replace. When I did this I know have 4 that sound weaker. 1,2,5,8.

I took one of my new ones and plugged it into the #1 spot, it did not sound any stronger than the one that was already there! I ordered the Injectors from Diesel Care out of Memphis TN.

So I guess what Im asking is, where should I go now. Throw the v/c's back on it and do a contribution test?

Does the intensity of the "buzz" mean good or bad. Or is just that fact that it buzzes they are good. Every time the buzz test was done the scan tool came back and said the test passed.

Thank In advance

Bill

 

A contribution test would be helpful. The intensity of the buzz is hard to diagnose over the internet. What are the temps where you're at?

I'd do several buzz tests in a row and see if any of the "weak" injectors get louder after repeated buzz cycles. If they do, that indicates sticking poppets and a good place to drop in the remans.

 

I ran a total of 8 buzz tests the intensity of the buzz didn't change at all during the testing. 3 4 6 7 were the loudest. I have the turbo off now for a rebuild, I think I'll do a contribution test after I get the turbo back on before I start pulling injectors

The temp today was low high 60s when I was doing it.

 

I see two problems here....

You replaced two injectors when you should have replaced them all if you think it's the actually injector. The others are not far behind.

The first thing I would check before pulling sticks is the valve cover gasket harness connection. I'm betting you have some sorched pins or melted pigtail.

Also you don't have to remove the turbo to do the injectors, but since you did I'd inspect the oil supply/drain o-ring and replace if it needs it.

How many miles?

 

8 buzz cycles should be enough to wake up a few sticking poppets. After you get the turbo back on, you might leave the valve covers off and watch for oil discharge out of the weak injectors and compare them to the good ones. That will give you something to do while the engine warms up for the CCT (unless you've got a resistor for the EOT handy).

 

I just hope I can get it run period. When I brought it to the house, I had to put it in 4lo to back up to the spot where I work.

 

Getting ready to click 300k I have yet to replace any injectors, I did glow plugs last winter along with new gaskets uvch's. The turbo was pulled because it motivated more oil in the intake tract than air.
Its freshly rebuilt now so that shouldn't be an issue.

I do agree the others aren't far off, but unfortunatly the budget doesn't allow for all 8 right now. I wish it did, but I'm working with all I can right now.

 

I thought you were exaggerating about the dead hole earlier. Check the blowby once you get the turbo back on. You shouldn't have to put it in 4 low to move the truck, even if you drop 4 injectors. We had an 02 at work that got a bad injector solenoid. The IDM shut down the entire bank. Truck ran like poop for the 30 miles it was limped back to the shop. One new injector later and the truck ran like new again.

I'll also second checking the UVCH & pins. Just because they were replaced does not mean there's an issue. I've got 309k on my stock sticks, so don't feel too bad, but if you really have a dead hole, then you'll need more than just injectors.

 

1) BUZZ TEST IS USELESS!!!!! Unless you're a mechanic with a decade of PSD experience to know what sound to listen for. Even then it's no where near as accurate as the CCT.

2) Cylinder Contribution Test is your friend. Put it back together and run the CCT.

3) I don't sell injectors one at a time (unless you want a new one) because if one has an issue the rest will drop one by one soon after. If you want to keep the truck, look into doing all 8. And if you want a performance upgrade think twice about Diesel Care injectors...

4) "8 buzz cycles should be enough to wake up a few sticking poppets." Sorry, but this makes no sense whatsoever. No such thing as a 'sticky Poppet'. ???

 

We put it back together tonight. Ran another buzz test, passed, started the truck. TOok about 3 trys to get it to start, then ran rough as a cob till it warmed up. When it was running rough it had no power at all. We did put fresh oil and filter. There is A LOT of blow by cold, it seems to ease up a bit as it warms up. When it finally comes up to temp it runs great. When cold it's a gutless shaking quivering pig.

What now?

 

When you say blowby, are you referring to smoke coming out of the oil fill tube, of can you feel the Puff, Puff, Puff pressure coming out of there? If you flip your oil cap upside down and place it on top of the fill tube with a cold engine, does the blow by shoot the cap off the tube, or does it just kind of vibrate itself off?

I know Jim doesn't like my referring to "sticking poppets", and the description may not be entirely accurate, but on some higher mileage trucks, especially those with a less than stellar maintenance history, cold thick oil can cause the poppets to not bounce off the upper and lower seat (the buzz noise) which can cause a very, very faint buzz noise. These "sticking" poppets often cause a hard / slow start issue and/or lack of power when cold but seem to improve when the engine warms up (EOT gets high enough to provide less resistance for the poppet movement allowing the injector to wake up.)

Sounds like you need to wire a resistor into your EOT circuit and run a CCT and watch the rotational velocity numbers on a cold engine to see what's acting up.

While I don't believe it's really mandatory, I will agree that with 300k on the injectors, if you need to replace one, you might as well do them all. When one of mine goes, I'll be putting 8 in.

 

When we got it warmed up last night I tried to run a CCT. The scan tool would go to a CCT it would sound as if the engine was going to die for a split second, then would pick back up, and I would get a code refering to the EOT sensor. Where is the EOT located and what size resistor do I need to wire in to fool it so I can run a CCT?

 

Blowby, A constant push of smoke coming from the dipstick tube. Looks like a fog machine out of the dipstick tube. flipped the oil cap, doesn't blow it off, just kinda vibrates there with the motor.

Yet again GUTLESS this morning till the temp came up. After the temp came up, it ran great.

Not plugged in last night started fairly easy, one heat of the glow plugs, started up, ran rough with a grey smoke that cleared up quickly.

Any Ideas?

 

Unplug the EBPV on the turbo and see if that changes your gutless issue.

Jim is right though.
Replacing 1 or 2 injectors isn't a good idea. I had 3 remans in my truck when i replaced all 8, and 2 of the remans had leaky o-rings on them, and 1 was carbon'd above the lower fuel o-ring. They probably came out of the place you purchased your injectors, seeing as my truck is from Polaski Tenn.

Try cleaning your Doghouse on top of the drivers side valve cover and see if that helps with the smoke problem.
Mine does it also, its just part of high compression engines and high mileage.

 

That's actually a neat idea I never thought of. You have to have oil temps to 160* to run a CCT test, and most times it will miss when cold and you have to warm it up to run the CCT, and by then the miss is gone.
I can't help with the resistor, but the EOT sensor is on the backside of the High Pressure Reservoir, driver's side. It's the only thing on the back of the HPOil res.