'95 PSD, 162, XXX, no chips or tuner, A/E scan failed inj. buzz test and Cyl. contribution test. Buzz test # 3 high low circuit fault. This is inj. that one year ago had broken poppet screw and was visibly an odd inj. I went and changed inj. still missed. A/E scan read failed buzz test # 3and # 4 ( different sides of engine, right?) This seemed crazy, just like a friends '97 when the dealer said bad IDM. I changed out the 120 volt IDM with '95 stock and it passed the buzz test 3 different times but failed on #3 contribution again. Wiring harnesses were burned and changed, all 4 connectors and gaskets last Nov.-Dec. I plan to go look at them with magnifier and ohm out. I'm kind of lost.

 

What CPS do you have? If you're only issue is now a failed CCT on #3, there's a chance it's related to the "new and improved" CPS from Ford or some after market model. What happens if you swap #3 and #5 injectors and run the CCT again?

 

No, please, tell me it ain't possible. It has a AutoXXXX CPS in it. I had one for a back up ( they owed me some credit), I have a Standard (?) for back up now, have to go look at the box. I Assumed, and we know what happens there, that it was the odd ball inj. that was giving me problems. The poppet screw had been broken and the Torx heads were stripped on two and had been slotted with hacksaw (?) to use flat screw driver. I can go try to swap them to see if it changes. I have the engine back together now, much easier to swap CPS than anything else. I put this one on when I purchased truck last fall, the original was really loose fitting in it's bracket, actually fell out.

 

Switched out gray CPS, put in black, no change still miss, says "passed" on buzz test though 3 sounds weak. Before replacing 120 volt IDM, both 3+4 failed buzz test. Now passes buzz but Cyl. Cont. test fails/fault continues. Will start early looking for burned pins and ohming wires.

 

Did you replace the solenoids as well ? ...

Did you ohm the wiring ?... a Cps won't cause your symptoms

Oh wait , since Chris is here , you won't need help from any of the rest of us ...

 

Replaced the solenoid with the inj. #3 as a unit. Like I tried to say earlier the solenoid looked pathetic. I just knew it was bad when the A/E said it failed both the buzz and contribution test. The one I installed was a rebuilt one. I will ohm in the morning. Thanks for chiming in, I really didn't think the CPS would do this, but had not put away my tools yet.

 

Cyl. 1+3 ohm out through gasket @ 3.4 and the same unhooked from gasket. Still pass buzz test with #3 sounding weak. Truck misses, Fails contribution test. With buzz test sounding different I'm inclined to think electrical. Thoughts? I have only driven aprox. 50 miles since installing inj. would this be the problem? Air?

 

How bad is your miss? I took your first post to say that you only had issues with the buzz test and CCT. Air is a possibility at 50 miles, but that would be more of a rough idle, not a miss. Was the miss there before the injector swap? Did it change any? I'd suggest pulling the valve cover back off and see if #3 is spitting oil with the engine running or maybe unplug #3 and see if the miss changes or stays the same. Where did you get the rebuilt injector?

Did the new CPS fit in there better than the one that fell out? Was the old one just missing the o-ring or something?

 

Removed valve cover earlier today, #3 seems to be flowing oil same as #1 and #5, #7 seems to flow more. Miss was present and reason for swapping oddball inj. when it failed both buzz and Contribution test I figured get rid or it. Also unplugged #3 and it really ran rough. Just drove it 102 miles and it really seems to have more power than before swapping inj. ( maybe my meds?) but there is still a rough running to it. I bought the inj. from a reputable company and they said that even with one inj. removed you need to run it 150-200 mile to purge air, I'm real close to 150. I thought I had ran it enough. But the buzz test issues are electrical not hydraulic right? But serious, it runs rough/miss but has more power than before swap.

 

This is the hard part about diagnosing things across the internet. We need to figure out what you're calling a miss is what some of us would call a rough idle. Some possibilities for a rough idle could be CPS issues, oil needing a change or improper additives, air still in the system, or maybe worn injectors. A miss could be mechanical or injector related as well.

When I've started a truck with one injector unplugged, it had what I would describe as a slight miss. Since unplugging #3 made your miss much more severe, then either you have more of what I would consider a rough idle or you have another cylinder where the miss is located and disabling the 2nd cylinder made it that much worse.

I'd suggest you don't get too hung up on what AE is telling you, just use it as a tool. There are several things that AE cannot tell you, so keep your mind open. How is the oil and is it due for a change? Got any other injector solenoids that look like they've had a hacksaw taken to them? Have you checked 2-4-6-8 to see if they're spitting oil? Does the miss get better, worse, or stay the same from a cold engine to fully warmed up? Is it still getting better the more you drive it? Is the miss only noticeable at idle, or when driving too? Do you have all your power back or is it down on power?

 

I guess i depended on the A/E and there is a bit more to do. Truck is little over 3k in oil mileage, I try to change all the diesels 3000 if working hard to 5000 if being used as grocery getter. No additives. Only owned this truck 11 months/10k miles. I picked up a compression tester and the plan is to take it back apart, check all inj. by unplugging and doing a comp. test on all driver bank cyl. I now have 212 miles since installing inj. truck has a little more power than before change but is still lagging and has a miss/shudder to it. None of the other inj. look like this oddball one I changed out. I will go back through each one, both sides and look for anything, loose poppet etc. hopefully next post will have more data and hopefully answer. Thanks.

 

Removed valve covers, unhooking inj. one at a time with bad miss when each one disconnected. Removed pass side, #4 ( that is the second one back right?) NO CHANGE. The poppet screw had backed out. This was like this about 10 months ago. I replaced with one that is an Allen type head, socket head screw. Question, why if this one is #4 did A/E tell me #3 was failing contribution test? I tested fuel pressure and had 60#. I am happy I found it, not happy about the process. I plan to check each inj. poppet screws before reassemble.

 

Yes #4 is the 2nd one back. I can't tell you why #4 didn't show up on the CCT. That's why I was saying not to put too much faith in AE. It's a great tool, but it doesn't always have all the answers. Sometimes we have to figure it out for ourselves.

In the beginning you did have issues with #3 & #4. The #3 failure you continued to see may go back to the CPS issue. The new ones don't like #3 and often times #8 for some reason.

The good news is we're at least making progress on this. Since you're having so many injector issues, it may be a good idea to just pull them all and send them to Jim to get them all fixed right. Might save some future headaches.

 

Sorry double post.

 

Well, actually #4 didn't show up at all till after I changed out the goofy looking inj. and then only on the buzz test. After I changed the IDM then 3+4 passed with others on buzz test but CCT continued to fail on #3. I guess it's possible I did not completely clear stored codes (as in from previous tests). There were 0 stored codes for inj. related issues. I will unhook batteries, touch cables together and leave unhooked over night. Not able to pull inj. right now, but 7 will definitely need to be addressed soon.
I'm used to cracking lines to see what's messing up. Thanks again All.