Possible Cam\Tappet issue

[cerberusiam]

I just got my new cyl head.

What got messed up on your old head that you needed a new one?



Should have clarified my description a little better, I am talking about the distribution head and rotor on the IP.

 

[Greenleaf]

Oh, the dist. head... ... .



Yea, that sounds better. Was wondering how the fuel was passing from one cyl to another... ... ... ... ...

 

[NIsaacs]

Oh, the dist. head... ... .



Yea, that sounds better. Was wondering how the fuel was passing from one cyl to another... ... ... ... ...

Lol, yeah me too! I was afraid to say anything because the OP sounds like an awesome mechanic!



Nick

 

[jwinnie]

cerberusiam,



Just to clarify, you sent the pump to a shop to have it tested, they said it was ok, now you find you have a bad pump head??? #@$%!

 

[Greenleaf]

I have used a fuel injection pump test stand, and you measure the amount of fuel delivered from each port, so I don't know what the "test" would have included... ... ... ... ...

 

[cerberusiam]

cerberusiam,



Just to clarify, you sent the pump to a shop to have it tested, they said it was ok, now you find you have a bad pump head??? #@$%!

Imagine that, huh?



Pump checks out for flow and delivery pressures, but, AFAIK they are not checking for pressure spikes in all ports nor the timing of the injection event. Right Scott?



Not sure thats even possible, you would have to data log the pressures on all the ports in firing order to really see something like what I **think** is happening, then be able to log the timing of the event to see where it actually is firing in crank degrees.



On a CR where everything is electronic that can be tracked on a data logger as all the info is there, and its critical to get things to run correctly. On a mechanical pump its really tough cuz there is no way to log a lot of this data. You puts the pump together to spec, make sure it holds the pressures and flow, and it should work. Until some really strange thing comes up, then its head scratching time.



We talked to PDR and several other shops about the symptoms, possible causes, what we had done. Nobody has seen this exact problem, and everybody says its in the pump. The only thing we have not replaced with NEW is the case and distribtuion head. I dunno, its a head scratcher for sure.

 

[Greenleaf]

It would be worth the time to install a loaner/known good pump.

 

[cerberusiam]

It would be worth the time to install a loaner/known good pump.

If I had one or could put my hands on one that would be the optimal thing to do.



The only known good one I have is in service in GA. Getting it off and to WA is just not going to happen right now. :-laf

 

[Greenleaf]

Want to borrow mine?

 

[cerberusiam]

Want to borrow mine?

You have a spare or are the trucks still garaged for the winter?

 

[Greenleaf]

I have a known good spare that I had run some years back. I believe I had serviced it with a gov spring, new drive shaft seal and possibly a few other mods like a modified lever etc. etc.



I have not run it in some time and can't quite recall what all I had done with it, but it is a known good unit that performed quite well.



It is a replacement pump back when Mopar was recalling them in 1993. Still has that MOPAR tag.

 

[cerberusiam]

I have a known good spare that I had run some years back. I believe I had serviced it with a gov spring, new drive shaft seal and possibly a few other mods like a modified lever etc. etc.



I have not run it in some time and can't quite recall what all I had done with it, but it is a known good unit that performed quite well.



It is a replacement pump back when Mopar was recalling them in 1993. Still has that MOPAR tag.

Thank Scott, hold that thought until I check with my son and see where he is at with a different pump. He was at NHDRA event last weekend and had a line on one but haven't talked to him lately.



I am traveling today so will let you know later. Appreciate the offer.

 

[NIsaacs]

Is the pump in question the same pump as the one in your original post? The one you installed on a different engine with the injectors and it run fine? The one that had a problem with #3 and now #1 is the problem?



It's been quite a while since I worked on one. Is it possible to get the pump 180* out? The old Rosa Master pumps (simular to the VE) on Allis Chalmers diesel's would run that way but not right.



If the pump is good, injectors are good, the compression/cam timing is good maybe it still might be an injector line?



Nick

 

[cerberusiam]

Is the pump in question the same pump as the one in your original post? The one you installed on a different engine with the injectors and it run fine? The one that had a problem with #3 and now #1 is the problem?

Yes, the same pump and injectors moved to another truck and it ran without the problems of the first engine. The problem on the second truck (92) was it had no power and was extremely lazy. On the first truck (93) it was quite powerful and would light the duals on an on-ramp but rough idling and a definite drop in a cylinder firing pattern. On the second truck it was a struggle to get it to 70 mph but it was relatively smooth with none of the rough exhaust tone or miss.



Checked everything over and it all looked good so bumped the timing gear 1 tooth and all the power came back, but, now we have a problem with a cylinder firing when the exhaust valve is open. It was better than the first truck but still an issue when we timed it correctly. Different than the problems on the first truck but still an issue.



Further information, pulled the guts out the DV on #1 cylinder on the 92 engine and now the exhaust fire is gone and the idle smoothed out. Hmmmm??? Power is good, will make 38 psi on an HE351VE set to about 14 cm, but, once you hit higher rpms things get rough and engine starts sounding unhappy.



He did a full bore WOT run and when it hit the top of the rpm band the truck just nosed over, started back firing and blowing white smoke. Pretty sure its draining the fuel and is running short with that test, but, still getting some weird engine reactions when you do a hard pull up to around 2800 rpms.



SOMETHING is not right with that head and rotor even though they mic out good. SOMETHING is different between that 92 and 93 engine also, time them the same put the same pump and injectors on them and they react totally different.

 

[NIsaacs]

One other thing I just remembered is the fuel return. If there is any restriction on the system they will cause problems. Is that a possibility? I can't remember if the little brass screen is in the pump or in the line next to the pump. If it is in the line of the truck that runs bad maybe it is plugged?



Nick

 

[cerberusiam]

One other thing I just remembered is the fuel return. If there is any restriction on the system they will cause problems. Is that a possibility? I can't remember if the little brass screen is in the pump or in the line next to the pump. If it is in the line of the truck that runs bad maybe it is plugged?



Nick

Checked that all and the pump\injector return seems to be fine. I THINK my son checked it all the way to the tank but will ask him again.