Help! 7.3 No Start
Thread Starter
|
New User
Joined: Sep 2018
Posts: 8
Likes: 0
Help! 7.3 No Start
Hey guys, I've got a early 99 7.3 with an edge evo tuner that I can monitor with. 2 days ago I had a crack no start but it was just a glow plug relay no big deal. Today I have a crank no start and I'm confused. My monitor reads I have 178ish rpm so I don't think it's my CPS, I unplugged my ICP still no start so I'm pretty sure that's good. I read 0 psi injection pressure though and that makes me think my IPR is bad but I'm not sure. Some possibly good info would be that my CPS, ICP, IPR, injector O rings, glow plugs, valve cover gaskets, fuel bowl heater, and fuel filter have all been replaced within the last 10,000 miles. I recently checked and filled my hpop with oil, and I gotta spare CPS and ICP in my glovebox I could throw at this thing before I have to go to the store. Thanks for looking!
Thread Starter
|
New User
Joined: Sep 2018
Posts: 8
Likes: 0
Update
I'm pretty sure i've got fuel pressure but I haven't put a gauge on it. I got the damn thing to start after cranking forever. Watched my icp value go up from 0 to 500 by tens, once it finally got there it fired and magically had oil pressure again. But it ran like dog ****, stutters, stumbles at 1800 rpm, I'm stumped.
Lead Driver
Joined: Dec 2006
Posts: 7,092
Likes: 145
From: San Diego, CA
If you're hearing your fuel pump run when you turn your key on then you're probably okay (it's on the inboard side of the frame rail under the driver's door).
What brand of sensors did you use? You can get lucky but for the most part our trucks like OEM. You can unplug the ICP sensor and see how it starts/idles. If that fixes the problem then it's that sensor. Also check the plug for oil. Yes, I know you replaced it 10K miles ago but I've seen stranger things happen. It's free so you've got nothing to lose.
Dumb question - have you checked your oil level? The 7.3L doesn't need to be topped off but when it starts to get low it will let you know.
What brand of sensors did you use? You can get lucky but for the most part our trucks like OEM. You can unplug the ICP sensor and see how it starts/idles. If that fixes the problem then it's that sensor. Also check the plug for oil. Yes, I know you replaced it 10K miles ago but I've seen stranger things happen. It's free so you've got nothing to lose.
Dumb question - have you checked your oil level? The 7.3L doesn't need to be topped off but when it starts to get low it will let you know.
Trending Topics
New User
Joined: Mar 2010
Posts: 22
Likes: 0
Can you get us a couple of parameters from the edge to help you troubleshoot? Batt voltage, ICP(psi), IPR (%), RPM. Check the HPOP res level again
Last edited by j1586; Sep 18, 2018 at 05:13 PM. Reason: forgot info
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Thread Starter
|
New User
Joined: Sep 2018
Posts: 8
Likes: 0
I replaced most the sensors from napa and the ipr from oreilly's, I unplugged the icp and it still ran like ****. I even threw a known good one on and it didn't change anything. Some values I'm getting are about 180rpm cold, the ipr duty cycle goes up to about 94-98%, my icp slowly goes up pretty much by 10's 10,20,30,40 for like 15-20 seconds of cranking where it eventually reaches 500 and starts up. The idle is rough as hell and it's got no power, at about 1800rpm the thing almost sputters and pops. Thanks guys
New User
Joined: Mar 2010
Posts: 22
Likes: 0
Check the HPOP res level again, if it is not going down then the problem is in the High Pressure oil system. From experience I would start with the injector orings. If you have a scan tool (ford, AE) that does a power balance/cylinder contribution test it can help narrow it down. If not you can replace all of them with the engine still in the truck. If one has failed I would recommend doing other of them.
Thread Starter
|
New User
Joined: Sep 2018
Posts: 8
Likes: 0
Attached is a data log collected by my edge tuner of a short run around the block I did after I finally got it to fire. I honestly think the values are fine but the thing runs awful and knocked a few times. Oh and yes I did check the oil level, it is right where it should be.
New User
Joined: Mar 2010
Posts: 22
Likes: 0
Where are you at? I had this same problem. I could only start/ run the truck in a high rpm setting on the tuner. When I pulled the injectors 4 were leaking by and 2 others were almost completely blown out. Are you getting any black smoke? If that is the problem the truck will get harder and harder to start. It will not start when hot and eventually not start at all.
Postmaster
Joined: Nov 2015
Posts: 4,807
Likes: 125
From: Colorado Springs
I replaced most the sensors from napa and the ipr from oreilly's,
I unplugged the icp and it still ran like ****. I even threw a known good one on and it didn't change anything. Some values I'm getting are about 180rpm cold, the ipr duty cycle goes up to about 94-98%, my icp slowly goes up pretty much by 10's 10,20,30,40 for like 15-20 seconds of cranking where it eventually reaches 500 and starts up. The idle is rough as hell and it's got no power, at about 1800rpm the thing almost sputters and pops. Thanks guys
I unplugged the icp and it still ran like ****. I even threw a known good one on and it didn't change anything. Some values I'm getting are about 180rpm cold, the ipr duty cycle goes up to about 94-98%, my icp slowly goes up pretty much by 10's 10,20,30,40 for like 15-20 seconds of cranking where it eventually reaches 500 and starts up. The idle is rough as hell and it's got no power, at about 1800rpm the thing almost sputters and pops. Thanks guys
‘Buy your sensors from Ford or Clay at RiffRaff Diesel and you’ll get quality sensors you KNOW are OEM.
