Join Date: Dec 2006
Location: Austin, TX
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2001 7.3 Hard Start (all the time, whether cold or hot)
This is going to be a bit long winded, but I want to make sure to provide as much detail as possible. Also, I will be posting this on several sites, so if you see it again you know why.
So here it is.... I’m having an issue that has me so worked up I can’t think of anything else. I have a hard start issue with my 7.3 that occurs whether its cold, warm, or hot. Doesn’t matter if I just ran the truck or let it sit overnight.
2001 F250 7.3 4x4 with 177k miles. Mods: K&N air filter, BD 80hp chip (which has been removed and will not be reinstalled until I can resolve this issue - note: problem occurs whether the chip is in or not).
Hard start regardless of ambient temperature or truck temperature. Turn the key, engine turns over at normal crank speed, after 5-10 seconds it starts or not at all. A second (or third) try will usually get me running. Once in running, the truck runs fine.
Started having intermittent stalling and no RPM on restart…. CMP, had this before at 39k. Replaced the CMP and solved this issue. But while replacing the CMP I noticed my oil filter was loose and I was 5-6 qts down on oil. This had to have occurred during the previous day or so as I check all my fluid levels each time I fill up with fuel (which was 2 days earlier). So I fill the engine with oil and check the HPOP Reservoir, of course it was low, so I topped it off to about a ½” below the top. Engine still has trouble starting, but once started runs fine. After this little fiasco I decided to do my 180k maintenance now. So I changed all fluids (engine, tranny, x-fer case, diffs, coolant) and all filters (oil, fuel, tranny). Also note, the SES light does not come on. It did when the engine would stall prior to changing he CMP, but has come on since.
Well, since then I have been having issues starting the truck. So here is what I have done thus far in my trouble shooting efforts:
- Replaced CMP (now when I crank I get tach movement)
- Replaced GPR (this resolved the not starting at all / extremely hard starting. Now it starts, but is not back to normal)
- HPOP Reservoir level (since I topped it off, it has stayed constant)
- Fully charged batteries. Both are >12.4V and the engine appears to crank at normal speed
- Battery load test showed both batteries were good (935cca & 1030cca). Had it done twice on seperate days just to be sure.
- Removed IPR, appeared to be in good working order, cleaned, testes, and replaced o-rings.
- Verified glow plug resistance (all in spec) at the valve cover connectors (outside 4 pins on each)
- Verified ICP harness voltage & resistance checks (all in spec)
- Disconnected ICP connector and engine still starts with some effort (as usual) and runs fine (???)
So what’s next? I do not have a code tester, but plan to pick one up the next time I’m in town, which may be a couple days. But if I'm not getting an SES, will the PCM still be putting out codes? Either way, if I buy the $175 unit I could at least read sensor data while running. But until then I would like to keep trouble shooting as much as possible. So I am looking for any help to further diagnose the problem with what I have available.
Other areas I will check or have considered looking at.
- Voltage check to the PCM during cranking to verify if greater than 10.5V.
- CMP Harness
- IDM. How do I check?
- Relay for the PCM & Fuel Pump
- How do I check the ICP sensor itself to ensure it is good?
- HPOP rebuild / o-ring replacement???
- Have also considered that it might be low oil or fuel pressure.
Thanks in advance for the help