motor swapped wont start P0073 p0093

atsiauto · **Joined:** Mon Apr 01, 2013 6:55 pm **Posts:** 30

New timing belt 86k mile engine, just swapped into my 05 and it wont start. I have had a completely drained fuel head when engine was out and just replaced filter with fresh engine also have been bleeding the fuel head like a mad man , seem to get only fuel now but wont start up .

I have been slowly fixing this jeep since June and just have that booty kicked feeling after investing tons of time and cash . I don't want to keep cranking the engine , I get a light smoke/vapor out of the tailpipe but cant determine if this is combustion or just normal non running while cranking. I also log a p0073 code as well.

Please help if you can . Thanks in advance .. Scotty

papaindigo · **Posted:** Mon Sep 02, 2013 10:42 am

Codes are
P0073–AMBIENT AIR TEMPERATURE SENSOR CIRCUIT HIGH
P0093 - FUEL RAIL PRESSURE MALFUNCTION POSITIVE PRESSURE DEVIATION.
The former may relate to an unhappy (bad or not plugged in tight) MAP sensor which is referred to as a air temperature sensor in the parts manual. For what it's worth BOSCH # is 0 281 002 845 or GM PN 55206797 are acceptable substitutes per MrMopar64 and quite inexpensive.

Regarding the latter, I know there are a couple of sensors that relate to building and maintaining adequate fuel rail pressure to start and run. One of them could also be bad or not plugged in tight. I also recall that if the fuel system is completely bleed dry (e.g. no fuel in the fuel rail) it can take forever to build adequate pressure to run. Unfortunately what I don't recall is if there is anyway to "prime" that portion of the system and I'm not going to toss any hairbrained ideas of mine out there given the pressure that system is under. You might PM or email Sir Sam as I believe he may have dealt with the issue of starting a "dry" fuel system.

atsiauto · **Joined:** Mon Apr 01, 2013 6:55 pm **Posts:** 30

Update
Oddly enough the air intake sensor code seems to apply to the tiny air sensor in the grille! I just connected the large connector to the header/panel which has the outside temp sensor and cleared the code and it did not come back. Before it instantly came on after reset. I am still, (alas) catching the 0093 code which I strongly believe is lack of the cp3 priming itself or air in the rail so I would like to get some opinions on what to do next.

I also have slapped on a revised filter head which I had from the totaled 05 I purchased to get the engine (I was able to force fuel through the heater connection following re-bleeding 10x ) . I will however have to either buy the plug from the dealer or sift through the entire engine harness I saved from the totaled one to find the plug on the cheap.

papaindigo · **Posted:** Mon Sep 02, 2013 3:13 pm

2n thing first. I gather the vehicle you are working on now has a 2n gen fuel filter head (heater plug on driver's side if about the same size as the other plug as opposed to noticeably smaller). Finding the wiring pigtail should be no big deal in that pile of wiring. It's bright blue which is like no other plug I know of on the vehicle. If you cannot find it get PN 68043086AA for like $12-15. NOTE it comes with 2 sets of wires, don't ask me as you need only 1 set, and the colors don't match the vehicle wiring; just connect based on size and you will be good to go but be sure to insert the new wires in the new plug before connecting.

My personal bet, worth :2cents:

at least, is you are not building enough fuel rail pressure to fire the engine and I doubt it's the CP3 but beyond that I cannot offer any advice. I know there are several sensors involved and presume they can be tested somehow and I know from past posts that it takes a good bit of cranking to build pressure in a system that's been drained.

Unfortunately this is one topic for which I have not saved a copy of a solution post. You might consider posting a question like "how do I prime the fuel rail after it has been drained".

It may be as simple as cracking the return line and bumping the starter without actually starting the engine until fuel flows. I just don't know and fiddling with high pressure stuff, given all the warnings, makes me very nervous.

atsiauto · **Joined:** Mon Apr 01, 2013 6:55 pm **Posts:** 30

I have read a thread on here involving cracking the fuel feed to the #4 injector open after some 5 sec cranking but it scares me to think what the risk of spraying 4000 psi fuel if done while cranking. I hit the motor with a small shot of ether today and it does run , I just don't intend on using ether again as I know its bad for diesels.

I seem to have a full filter and head just the code and no start, my next move is to try to monitor the fuel return tops and see if an injector is spilling back way too much return fuel and killing the pressure, this is all new to me so I am trying to learn as much as I can . I have 3 extra injectors, one of the original ones from the jeep I am fixing had valve failure and looked kind of doggedly ( beat up end) so I used one of the low mileage ones to replace it from the new engine ( my goal was to keep the low mile ones for my other jeep I have not begun to fix yet)

MRausch82 · **Posted:** Mon Sep 02, 2013 7:43 pm

atsiauto wrote:

I have read a thread on here involving cracking the fuel feed to the #4 injector open after some 5 sec cranking but it scares me to think what the risk of spraying 4000 psi fuel if done while cranking. I hit the motor with a small shot of ether today and it does run , I just don't intend on using ether again as I know its bad for diesels.

That was not a good idea. This can lead to broken piston rings, bent rods, and other broken items. May not show up right away, either. I have had to rebuild many VW diesels after some jock sprayed starting fluid in them claiming that it was fine to do so. I have some examples of bent rods and broken piston rings in my garage hanging up as a result. Same goes for glow plugs. Have seen some of these broken as well from ether use. Be advised.

atsiauto · **Joined:** Mon Apr 01, 2013 6:55 pm **Posts:** 30

I agree . I won't use it again.

racertracer · **Posted:** Tue Sep 03, 2013 4:45 am

Either destroyed a CRD at the diesel shop..... trashed the bottom end. Lack of fuel delivery led to the use of the either decision.

Our CRDs are not like the old Detroit diesels.

First - recheck all your sensor connections.

2nd - it sounds like a lack of fuel issue

DOC4444 · **Posted:** Tue Sep 03, 2013 6:26 am

What about using something like WD-40 instead of ether?

DOC

MRausch82 · **Posted:** Tue Sep 03, 2013 7:45 am

Nothing should be used in the intake. It can hydro lock, even momentarily on one cylinder and break rings. Hopefully damage was not done. Unfortunately you may not know it right away if it fractured a piston ring, etc.

atsiauto · **Joined:** Mon Apr 01, 2013 6:55 pm **Posts:** 30

Im trying to buy the miller test vial set to use and see if I have a leaky return on an injector .I am reasonable sure the rail is full just no injection is occurring due to lack of high pressure.

MRausch82 · **Posted:** Tue Sep 03, 2013 7:54 am

atsiauto wrote:

Im trying to buy the miller test vial set to use and see if I have a leaky return on an injector .I am reasonable sure the rail is full just no injection is occurring due to lack of high pressure.

Just crack #4. It won't build the really high pressure unless the system is sealed and has the resistance of the injector. No real danger. Just don't put your finger on the fuel line to test it... And no more ether!

atsiauto · **Joined:** Mon Apr 01, 2013 6:55 pm **Posts:** 30

Mike when youbsay crack #4 is this after a few 5 sec attempts to start or whilst cranking (2 person) ??

MRausch82 · **Posted:** Tue Sep 03, 2013 8:16 am

atsiauto wrote:

Mike when youbsay crack #4 is this after a few 5 sec attempts to start or whilst cranking (2 person) ??

My understanding is to crack it, then crank for no more than 15 seconds or until fuel comes out (under 15 seconds). If nothing, wait a few minutes and try again. It is possible that the injectors are not the same as the original motor, and the ECM needs to be programmed to those injectors, unless you used your originals and they are in the same location as on the old engine...

atsiauto · **Joined:** Mon Apr 01, 2013 6:55 pm **Posts:** 30

One in the front is from the donor engine as valve faces were bouncing around like a lotto drawing and it appeared the injector tip took some direct hits. The other 3 were originally in the jeep labeled and installed in the original positions w new seals.

MRausch82 · **Posted:** Tue Sep 03, 2013 8:29 am

atsiauto wrote:

One in the front is from the donor engine as valve faces were bouncing around like a lotto drawing and it appeared the injector tip took some direct hits. The other 3 were originally in the jeep labeled and installed in the original positions w new seals.

Did the numbers on top of the injectors match the old one? It is possible, still, that the computer needs to be reprogrammed to accept that different injector. I seem to recall hearing of this issue before. Either way, try opening/cracking loose the #4 injector line and see what happens. If nothing, you'll need to trace the issue, and I'd start with verifying the injector numbers. Call GDE, he may be able to give some more insight on that. You may also want to check the crank sensor as well.

Jay ne Ohio · **Joined:** Sun Dec 12, 2010 5:49 pm **Posts:** 216

I would say that you still have air in the line somewhere or the pump has failed (unlikely). I had to remove the high pressure rail when I took the head off of mine. I had also removed the fuel head. After reinstalling everything, I bled the head. I cranked for about 10 seconds and it fired right up. Should not need to "crack" the injectors (I've had to crack the injectors on older Detroits, Deere's, and CAT's with mechanical injection pumps), but I guess it won't hurt anything either, as long as you are safely away from the line when cranking.

I would lean toward air leaking in somewhere between the pump and the fuel tank. Most likely location is the fuel head, but check your connections from the pump to the fuel head too.

atsiauto · **Joined:** Mon Apr 01, 2013 6:55 pm **Posts:** 30

I have noticed when I prime then crank the primer loses the hard pumped up feel immediately. My theory was the pump consumes the lightly pressurized fuel leaving me to be able to pump away again . Or is the primer only used for bleeding? I can't get any air from the bleed now so im assuming that up to the fuel head at least am not gathering air .

MRausch82 · **Posted:** Tue Sep 03, 2013 9:05 am

atsiauto wrote:

I have noticed when I prime then crank the primer loses the hard pumped up feel immediately. My theory was the pump consumes the lightly pressurized fuel leaving me to be able to pump away again . Or is the primer only used for bleeding? I can't get any air from the bleed now so im assuming that up to the fuel head at least am not gathering air .

Mine does the same thing... seems to be "normal."

atsiauto · **Joined:** Mon Apr 01, 2013 6:55 pm **Posts:** 30

Thanks for all your help Mike and others.

motor swapped wont start P0073 p0093

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