Ford 7.3L Power Stroke (1999-2003) :: RPMs Dropping To Low When Coming To A Quick Stop
Jun 10, 2017
I recently started noticing that when I am coming to a stop(usually a quick stop), the trucks rpms drop to low. hard to tell how low but looks like around 450-500 rpms. I can feel the truck struggle just for a second then the rpms bounce back to 650-700. i was sitting in my truck while in park and was revving up to about 1200 and then let off the pedal and it died. My positive battery terminals are getting pretty bad and am going to replace them soon(waiting on parts). Could this be the cause?
View 14 Replies
Advertisement
RPM's are dropping way off when coasting downhill while towing (as if the motor shut down), CC is on and maintaining desired speed. When at the bottom of the hill, all of a sudden, with a big bang(in the motor) the rpm's have came back up and you drive on down the road as normal. This seems to happen only when towing. "99 F250 7.3 I haven't pulled any codes as of yet. Whats happening?
View 14 Replies
Have a 2003 F-250 with 174,000 miles. Recently replaced CPS and ICP and it's running much better. It normally idles at about 700 rpm. Lately, after driving for any distance above ~40mph, when I come to a stop, the rpm won't drop below about 850 rpm. If I shift to neutral (automatic trans), the idle drops to around 700. At the next stop sign/light, it's back up to around 850.
View 11 Replies
I recently had a flat tire - Schwabs fixed it. Then told me my rear brakes were bad so I replaced them. I noticed when coming to a stop the last 20-30 feet you can really feel the front end vibrate - almost like it is in 4wd but it is not. I checked the hubs and they are on auto and lifted the truck to spin the wheels and made sure everything was dis-engaged. My front rotors were bad so I replaced them and the pads thinking it was the root cause. I also greased the front wheel bearings using the little tool from riffraff diesel where you take out the speed sensor and insert grease.
View 10 Replies
So the truck has been stalling out and dropping power randomly, symptoms pointed to needing the 50 cent mod, changed the cps for cheap insurance and peace of mind just in case it wasn't the uvch, no dice. So last night I yanked valve covers for the first time here's what I did while I was under there, check my work.
1st I ohmed out injectors thru the 42pin harness according to tuglys sig link. My meter would only go down to a 0.4 when testing the test leads just to each other
DS injector ohms
#2 3.5
#4 3.4
#6 3.6
#8 3.6
PS injector ohms
#1 3.6
#3 3.6
#5 3.5
#7 3.6
DS glow plug ohms
#2 prong to ground 2" away 0.9 ; white connecting wire back to gp relay 0.3
#4 0.9 wire to relay 0.5
#6 infinity ohms up thru highest meter setting, checked multiple times and different ground spots,(replacing tonight) wire to relay 0.5
#8 0.5 wire to relay 0.5
PS glow plug ohms
#1 1.0 ; white wire back to relay 0.6
#3 infinity multiple tests as well (replacing tonight) wire to relay 0.5
#5 0.9 wire to relay 0.6
#7 1.0 wire to relay 0.7
Next up, ebp sensor was reading 1.9 higher than map/baro koeo, gently cleaning sensor earlier didn't work. Installed new motorcraft, will check it with Torque pro koeo once the batteries are reconnected
Next I checked the uvch connections which felt good, darn it, maybe a smidge of movement from the DS, but nothing halfway disconnected or anything. Hmm. I ground down the quarters to the top of his head and installed.
Next I torqued down the 4 bolts per cylinder of the rocker arms at 20 ft/lbs, all were perfect and snug
Next up, injector torque. I've read on here below 50, or 80 in/lbs depending on different threads and opinions that I would need to replace o-rings.
So I set the in/lb click torque wrench at 50 in/# and tested the wrench's click on the higher torqued rocker bolts, then checked all the injectors, all were good
Reset for 80in/lbs, tested, then hit all injectors, #6 almost budged but clicked immediately before the handle moved
Reset for 100 in/lb, tested on larger bolt, 2 injectors took a 1/8 turn;
Reset for official spec of 120 in/lb , tested wrench, all injectors took 1/3 to 1 full turn
Reset for 130 in/lb (above official spec, but highly recommended on here by those way more knowledgeable than me on our engines) tested on a larger bolt, slowly and carefully gave all injectors almost an extra 1/2 turn to click; whew, finally a relaxed sphincter.
At this point I knew I needed to buy 2 glow plugs today, replace, then I'll check all glow plug torque at 14 ft/lb in one go, so I got everything ready for a hot torque after I do glow plugs tonight ("unloaded" the torque wrenches) and finally installed the RiffRaff AIH delete plug. My cell phone's alarm went off to get the kids ready for school, so hit the snooze and got everything put up. Now for a nap, then buy 2 Motorcraft GP and check back on here before going back at it tonight.
I also checked the turbo for play in all directions, was nicely solid and spun smooth, no wheel damage. Up pipes and well basically everything exhaust under hood had zero signs of soot/leaks with inspection mirror.
View 14 Replies
I do run a small battery maintainer during the winter months plugged into a three way with the block heater. Alright after sitting out side for approx 9-10 hrs in 22 degree weather I did these checks. Battery voltages at 12.55V and 12.6V on batteries.
Voltage coming into for was also 12.5V. When glow plugs activated I am getting 11V on the other side of the gpr. After cycling glow plugs battery voltages drop to 9.6V during cranking and as soon as she starts back to 12.5V.
Do these numbers sounds right? In my opinion isn't the drop to 9.6V during cranking a little low or is that the normal?
View 14 Replies
I have a 2000 F-350 dually. I am having an intermittent problem with the the OD light. The symptoms are after coming to a complete stop the OD light starts flashing and when trying to move forward it feels as if the brakes are dragging and sometimes stalls out the engine. The codes read with a Superchip 1705 are p1670,p0720, and P0503. When I shift into park, the engine rpms jump from idle to about 1500-1600. I have replaced both the differential VSS and the transmission OSS but still have the same problem.
View 4 Replies
my 2002 7.3 with 370k just started to puff a small cloud of white smoke on start up. i realize this is normal during cold months but it is currently 102* in Texas. it will do it on the first start up of the day or if i start it immediately after shutting it off at full operating temps and when i do get a smell of the white cloud it has a oil smell but this only lasts while the cloud is dispersing all of that only lasts about 2-3 seconds no loss of power good boost pressure when driving no rough idle at all nothing acting any different other than the cloud and the quick smell of oil...
View 14 Replies
I have a 2001 Ford Excursion Limited 7.3l with 199,980 miles on it.
It has a TS-6. My first problem is that when I come to a stop or slow down to a crawl then press the accelerator the engine stalls and dies. I have looked and looked at threads and can not find this example anywhere. There is no pressing the pedal and it remains at idle. It dies, shuts off, quiets. I have thought icp, tps, ivs
Second problem is that a/c is blowing hot. Other than being out of Freon, what could be other things to check. It does sometime go to default, but has done so in awhile. It does not blow cold in rear and hot in front. They both blow hot. I have replaced the pvh sensor.
View 1 Replies
How can I eliminate the factory Ford (2001 7.3) quick connect fuel line clamp on the output side on my OEM fuel pump? Do I just cut off the factory quick connect and add some 5/15 fuel line? Is it that simple or is there something I need to know prior to cutting off the factory quick connect clamps?
View 6 Replies
I have had my truck for about 4 years bought it used. I've replaced the motor due to #1 cylinder blowing up. So after I replaced the motor, it wouldn't start. Replaced O rings on HPOP (High Pressure Oil Pump) and started. When moving back to Colorado where I am stationed. It started getting harder and harder to start.
Then it got to the point where it wouldn't start so I would have to wait until I could start it or use a shot of starting fluid and yes I hate that. But I don't have a choice. I've bought new O rings replaced them and my IPR with upgraded screen. It fixed it for a week then the hard start came back. Tried unplugging ICP Sensor still hard start problem. ICP was reading 85%. When the truck is cold it fires right up no problems till it gets hot! Then driving down the high and hitting an off ramp it will shut off. When I try revers it will also shut off. The truck only has 111,252 miles.
View 14 Replies
Have to get rpm's over 2k before trans will engage, then in between shifts I either have to let off throttle or let engine rev over 2k to get trans to shift...
View 3 Replies
Was driving to work about 4 miles into my travel rolled around corned and she died..... tow bill and cps she fired rite up. Ran at idle in drive way because I was a little leary for about an hour left drive way went 2 miles went to pull in to store died again. Another tow bill and 2 more cps still won't start rpm is only like 200 when cranking but sounds like a lot more. The wts light works, batteries are pretty new, cps in new...
View 6 Replies
My '03 7.3 is "surging" on idle. When warmed up, and idling, the RPMs will drop by 300 or 400 for a few seconds and then will correct and shoot back up. It cycles like this (every 5 seconds-ish) continually . I just put in a new IDM and checked the UVCH - is there a separate idle control mechanism that I need to have a look at? (2003, 7.3, 214K, stock).
View 14 Replies
If I could determine the resistance of the accelerator pedal at around 1000 rpms, couldn't I rig up that resistance and switch it on in the accelerator pedal circuit to make the truck go to high idle? Any flaws in my thinking?
View 14 Replies
Ill start off with my mods and recent maintenance things I have done before fully describing the issue.
E99 7.3l with 190k on the clock
Full 5" turbo back
TS-6 chip
EGT, Boost and trans temp gauge
New ford glow plugs
Re-orings injectors
new valve cover gaskets
new fuel filter and fuel lines
new turbo with a ww2
Newer trans and oil pan
I think that should do it, now for my problem. The truck starts good cranks over once and is running with no hesitation, the engine run a little rough, more than normal vibration at idle almost like a small miss. No smoke at idle.
While driving with no/little load on the engine runs great , but under load there is a good amount of white smoke/ oil smell. The turbo is new and is not leaking oil I have already checked over that and the exhaust is new but there is some oil that is at the tail pipe in liquid form. The exhaust up pipe that goes to the turbo is not covered in oil either
The truck cruising in OD or in 3rd with O/D off around 2k rpms it shudders real bad almost like the truck is going to shake its self apart. but at like 2400 rpms and above its fine. Where is a good place to start the diagnosis as I am pretty new to the Diesel world. From what I've read it looks to be either rings are junk or maybe I have some bad injectors (thats what it feels like to me) but would that cause it to smoke like crazy?
View 3 Replies
the wife's '01 Excursion has developed a new idling quirk. While sitting, it will briefly drop rpm's. You can hear it, and see it on the tach gauge. No other noises or problems, except for the brief drop in rpm's.
View 3 Replies
Cruising down the street in my 7.3, i come to a stop, and I go to accelerate, and there's no power. It says "service engine soon" so if I try to turn it over again it'll just crank. But if I turn the key off and back on, it'll start right up. It's done this 3 times.
View 5 Replies
I just flushed my coolant system and installed a red ELC, Riffraff billet thermo housing, Ford thermostat, new hoses and Riffraff coolant filter. When I first started the truck and was waiting for the thermostat to open I notice at idle the flow from the coolant filter into the Degas bottle was a lot.
Fast forward a week and about 75 miles I have zero flow at idle and it will start to dribble at about 1300 RPM's and increase from there. It seems the flow would not be dependent of the thermostat being open since the connection is below it. I am wondering if my Donaldson filter is already full?
I used a flusher that uses air and water, after flushing I used air to blow to tap water out. How fast have you guys seen one fill up? I ordered 2 extra but just do not want to waste the first one
View 9 Replies
2003 7.3 excursion.. The truck starts every time revs up and idles about 3 seconds then the rpms drop and it tries to stall out catches itself then revs backup and idles rough similar to if you have got air in the fuel lines from changing the fuel filter.. About 1 in five times the truck will stall out and it starts and immediately and idles rough but the rpms and everything runs at speed and rpms don't drop again! This is a reman engine/transmission recently installed.. The mechanic who installed it was unable to figure the problem out.
View 6 Replies
Fine one day, no start the next. Been skimming over the 7.3 no start thread, so w got some ammo for him to check. White smoke while cranking, rpms move while cranking. Nothing to read codes or other sensors YET. Tried the unplug ICP and it "wanted" to fire. So, I have him my spare IPR to try. I'm sure he checked the fuses but will confirm via text...
View 9 Replies
