7.3 powerstroke miss

[svonasek]

I just started having a problem with my 95 powerstroke. Under acceleration it misses sometimes, but not all the time. It will cause the whole truck to shake violently. It seems to do it the most at around 45-50 mph. It starts and idle fine.

I'm thinking either injector or injector pump.

any ideas?

[Turbo302]

I'd check out the UVC harnesses (Under Valve Cover). They are real problematic on the later 7.3 PSD's, but I think the early ones had some issues as well.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=370235464377&crlp=1_263602_263622&ff4=263602_263622&viewitem=&guid=86fdcfa41260a02653769ce6ff8f02bb&rvr_id=&ua=WVI7&itemid=370235464377

Your not feeling the trans converter shuddering are you? Can you count/monitor the shift/lockup (I am assuming its an automatic). I had a friend with a 99' PSD and it would go 1st gear, 2nd gear, 3rd gear & Lockup shortly after, then 4th gear while locked. When it would go into lockup right after the 3rd gear shift, it would shudder real bad.

These are the things I can think of... Good luck.
Tim

[svonasek]

I'd check out the UVC harnesses (Under Valve Cover). They are real problematic on the later 7.3 PSD's, but I think the early ones had some issues as well.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=370235464377&crlp=1_263602_263622&ff4=263602_263622&viewitem=&guid=86fdcfa41260a02653769ce6ff8f02bb&rvr_id=&ua=WVI7&itemid=370235464377

Your not feeling the trans converter shuddering are you? Can you count/monitor the shift/lockup (I am assuming its an automatic). I had a friend with a 99' PSD and it would go 1st gear, 2nd gear, 3rd gear & Lockup shortly after, then 4th gear while locked. When it would go into lockup right after the 3rd gear shift, it would shudder real bad.

These are the things I can think of... Good luck.
Tim

I don't think it's convertor lockup. It does it at varying speeds. It happened when starting from a dead stop a couple of times, but mainly it does it at around 40-45 mph. It also did it to me while driving down the highway at about 60. It was running fine at 60 then would randomly act as if it had dropped a cylinder.

[Turbo302]

I don't think it's convertor lockup. It does it at varying speeds. It happened when starting from a dead stop a couple of times, but mainly it does it at around 40-45 mph. It also did it to me while driving down the highway at about 60. It was running fine at 60 then would randomly act as if it had dropped a cylinder.

Then I'd do some searching with regard to the 7.3 UVC harness issues. They will cause misses, hard start, sluggish performance, etc.. Any CE lights or codes? You could try an injector buzz test and maybe isolate it to one bank or the other. The problem is that it seems intermittant, so when you test it, it could be one of those days it works 100%.

[06powerstroke]

I had a 97 that did that same mis and it turned out to be camshaft senser. It never died it would mis sometimes under exceleration.

[svonasek]

I had a 97 that did that same mis and it turned out to be camshaft senser. It never died it would mis sometimes under exceleration.

It would be nice if it was just a cam position sensor. Those are cheap and easy to replace compared to injectors.

Every time i've had problems with the cam position sensor it would just die and would have to be restarted to get it to recover. I've never had one were it would just miss and then continue to run

[Chrm97PI]

get codes pulled, could be lots of things, like injectors, wires, IDM, cam sensor, injector o-rings.......