cylinder temps

[dds92780]

Okay i didnt know where to post this. Some of you may know that i have posted a few videos trying to get to the bottom of this

i popped the hood , set the throttle control at 1200 waited 5 mins, then let it back down after a min.

Here are my results starting with cylinder 6 first,

6 158

5 163

4 164

3 170

2 163

1 135

Bingo. so i know there is a misfire but what is it? I think its a stuck valve which might show why when we took the valve cover off a few months ago to do a valve adjustment and bridge work that it looked a lil dry. Compression in the cylinders should be okay. I am making plenty of power, i dont have blowby or even blow smoke nor can i smell any burning smoke. Sooooo experts, whats the next step? -Dustin-

Also, Injectors were rebuilt 3 months ago and pump was rebuilt and calibrated about 2 weeks ago too

[staxx]

Valves dont stick if they do they get bent , most likey problem is a defective injector nozzel need to pull them and pop test injectors . Cylinder temps dont really tell much unless you had a completely dead cylinder.

[theakerstwo]

I dont know which engine you have but i have a E6 i run ever day and i will share a problem with you that we had a discussion on a few months back.My engine started to shake when it was hot and pop thru the exhaust like a intake valve will do when it has excess lash.I changed injectors from a spare engine and set valves which it has a dnyitard brake.The pump was rebuilt two years ago and still same miss when hot. So i a few nights ago pulled and replaced the rockers from a different engine and bingo that was the problem. The dnyotard selnoid may have been leaking oil thru when hot. I have not seen that happen in years.

On another note some one ask about E6 and E7 rockers being the same. I used a set of rockers from a E7 engine having dynotard and its the same thing except the rock shaft stand brakets need reamed out a samll amount to use on the E6 engine which uses a larger bolt to hold down the rocker shaft stands. Which are 7/16 bolts.

[dds92780]

Good advice so far guys.

Staxx, a couple people have said it could be the injectors But i got them rebuilt 3 months ago. COULD one go bad that fast? Has this happened to you before? So you are saying if i had a stuck a valve or two they would get bent and make performance even worse? Do you think that maybe i just have permanant bent valves?

Theakers I think it could be my rockers too but the problem is that its not just when its hot, its at any temp. Almost feels like the camshaft has bad lobes on it and it doesnt like those rpm spots or seems like the cam is good but the valves are stuck and where the lobe is but i have zero knowledge on mechanics. I have been told that if i had bad lobes on my cam i would hear it more. I have posted a video of me doing 0 to 50 and it seems to make just as much power as a 427. So my question is, should i try fixing this or just use my truck as a money maker? Theakers, my engine is an e7 too e7 350 mechanical pump, 1995.

[staxx]

If your engine had a major issue it wouldnt be running so good , when cam lobe go down you get poping noise threw the air cleaner or exhaust because valve does not open if valves were bent you would have no compression on that cylinder so would be a dead cylinder . I have had brand new off the shelve injectors be defective many times and just think about how small the holes are on the injector tips if any debris got in fuel line or at injection pump its going to try to be forced threw the injector which will cause injector nozzel to stick open or closed slow to open bad spray pattern etc . Injectors also does not like water which when under psi acts like sand blasting notgood . Your rockershafts are most likely worn out because you sad it looks dry up there ,the oil passages in arms are blocked will crap you can remove rocker shafts and inspect also make sure you valve springs are ok not broken there are inner and outter springs . My bet would be a injector with bad spray pattern or sticking but you have good power I would drive it.

[dds92780]

Very well said! While i respect your knowledge and opinions, I called midwest injection yesterday and told them what the truck is still doing and asked if the injectors went bad is it covered under warranty? He said that they are. I even told him that i get 160-170 across the board on all my temps in cylinders except for 1 cylinder. he asked which cylinder. I told him it was cylinder number 1 which only got 135. He told me that isnt even something he would blink about or worry about because according to him it is normal for that cylinder to run colder than all of the others? Any agree with this? It is the cylinder that is closest to the fan and the intercooler but what else causes it to be colder? (assuming he is right)

Well, i then asked about if i had stuck valves which in turn would make them bent at this point what it would be doing and he said it would be making a popping sound and smoking a little and that is not anything that i have going on so scratch that. I am assuming the valve train is good.

Only thing i can think of is air trapped in the fill tube or some sort of air restriction in some line? He agreed that the restriction or problem is most likely external and not internal so i hope hes right on that. Only thing i can think of as to why there might be an air restriction is because the fill tube on the fuel tank is too short and if you still have 10 gallons or so in it, you will run out of fuel, but i don't think that would affect normal driving. Hmmm, i don't know what step to take if any at this point.

I need help on solving this never ending mystery. Cheers!