anybody tell me where my lift pump is?

gareth73 · **Posted:** Sun Apr 22, 2012 11:08 am

Hi guys my jeep is stalling when i pull up at lights and the revs drop,can anybody describe where the engine mounted fuel lift pump is? i think its faulty as when i open the tank cap to refill i dont hear that vaccuum suction that i used to hear.

DynoPax · **Posted:** Sun Apr 22, 2012 11:31 am

Unless you have an aftermarket lift pump, the only pump present is the Bosch CP3, mounted on the engine's driver side. Vacuum is created from the fuel filter head, using the primer. This feeds the CP3 toward the injection system... You may have an air leak, either at the fuel filter head or along the fuel lines to the tank. When issue occurs, check the primer. It should be offering high resistance, if not, you have an air leak...

papaindigo · **Posted:** Sun Apr 22, 2012 12:07 pm

Not to be difficult but I've never heard vacuum suction when I opened the fuel cap nor would I expect anyone to hear such a sound unless the tank vent system is faulty (e.g. air cannot get into the tank as fuel volume is removed from the tank). Imagine if you will you are drinking water out of a glass thru a straw; you don't hear a vacuum sound because as the water goes down air constantly displaces water you drink. In tank or on engine (what our CP3 is) fuel pumps move fuel by pushing or pulling respectively; neither system is new as both have been around for decades. In both cases the fuel tank has to have sufficient venting to avoid creating a vacuum or at some point neither type of pump can overcome the resistance the vacuum creates to getting fuel out of the tank; sort of the equivalent of putting your hand over the end of a vacuum cleaner hose.

If you are stalling under light load it's likely because you have an air leak as DyunoPax suggests (bleed your fuel filter - see Sir Sam's NOOB guide for a video on this topic) but if the problem persists and you have a 1st gen fuel head (see same video) it's likely that needs replacing OR you have a clogged fuel filter that needs replacing (recommended service interval 25k miles but 1 bad tank of fuel can clog a filter)

Herk · **Posted:** Sun Apr 22, 2012 2:54 pm

I didn't mean to hijack your question but someone might have a answer to your problem. Ok guys I just replaced the fuel head with a gen 2 which I already had. Replace the two quick disconnects fuel lines on top of the tank yesterday and I put a line fuel pump last week and it stall after 30 mins of driving. When I bleed it Im not get any air like use to. No codes either
HELP

WolverineFW · **Posted:** Sun Apr 22, 2012 2:58 pm

Someone else here had a similar problem and they found two faulty injectors on his vehicle. I think user name was Mozzio.

Herk · **Posted:** Sun Apr 22, 2012 3:15 pm

Interesting.

My issue started when I changed my fuel filter and added power service to the filter. Wont I get a code if the injectors were bad? It starts great, idle good. How about the line from the filter to the pump anyone had issues with this line ?

WolverineFW · **Posted:** Sun Apr 22, 2012 4:44 pm

I don't believe he was getting codes and they would only malfunction intermittently.

Start reading here
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=66074&p=726444&hilit=mozzio#p726444

gareth73 · **Posted:** Tue Apr 24, 2012 1:29 pm

much appreciate the info papaindingo,im always willing to learn how to look after my jeep.
after it stalled yesterday i wiggled the connector to the black circular metal box thing in this pic to the right of my fuel filter and it fired up,maybe a coincidence? any id on the part in question?

bugnout · **Posted:** Tue Apr 24, 2012 2:28 pm

See as your from yorkshire, this must be an export version 2.5 liter.

What year?

papaindigo · **Posted:** Tue Apr 24, 2012 2:30 pm

Looks like you have the Racor OEM fuel filter head which if OEM means you have a 2004 or earlier model and being UK it's right hand drive which means "stuff" is in different places under the hood/bonnet in comparison to the US models. Given that, I have no clue what the connector or box are but maybe one of our overseas members does.

Best I can suggest is go to Sir Sam's NOOB site and download pre-2005 factory service manuals and parts fiche. Maybe they will help identify these items.

gareth73 · **Posted:** Tue Apr 24, 2012 2:41 pm

cheers guys i will try a uk jeep site too,i just seem to get more help on this site.
Its a jeep cherokee 2.5 crd 2003 model.

papaindigo · **Posted:** Tue Apr 24, 2012 3:40 pm

gareth73 - don't bother. You need to do 3 things. 1) add a signature to your profile noting the year and engine of your CRD as that makes it much easier for us to help. 2) go to http://colorado4wheel.com/manuals/Jeep/KJ/ (the FSM/parts link from Sir Sam's NOOB guide) and download and save copies of the 2003 FSM and Parts manuals. 3) open the parts manual and go to Figure 14-730 for a picture of what that round thing with a plug is (pure luck I stumbled on it).

Looks to me like your stalling problem may be a loose electrical connection to your throttle control assembly. I'd suggest a bit of cleaning of the terminals and maybe application of some dielectric grease to keep out moisture. That may solve your problem.

gareth73 · **Posted:** Tue Apr 24, 2012 3:50 pm

papaindigo,dude you are a star! i will get right on that in the morning,thank you so much!!

papaindigo · **Posted:** Tue Apr 24, 2012 4:17 pm

Love the praise but let's see if what I suggested actually fixes your problem. If it does I'd say you could buy me a beer when we are in the UK in August but the closest we get to you is York I think.

Billwill · **Posted:** Wed Apr 25, 2012 3:20 am

That circular thing is the Throttle Control...sort of a "drive-by-wire" thing except that on our Export RHD models they are operated by a normal cable. You may have a bad connection or dirty contact there.

gareth73 · **Posted:** Thu Apr 26, 2012 2:47 pm

just wondered if i was bleeding the fuel head right,i was pumping the plunger and unscrewing the brass screw to try let air out but i read on a forum that a guy unscrewed the plastic cap with a slot in to let the air out?

gareth73 · **Posted:** Sun Apr 29, 2012 12:32 pm

jeep booked into garage tommorrow,the mechanic thinks its the fuel pump seizing.fingers crossed he fixes my baby.

gareth73 · **Posted:** Wed May 02, 2012 1:02 pm

garage says its the cps,so he changing my fuel filter too anyway and i get it back 2morrow.will post on here how it runs after.

tonycrd · **Posted:** Wed May 02, 2012 1:59 pm

Billwill wrote:

That circular thing is the Throttle Control...sort of a "drive-by-wire" thing except that on our Export RHD models they are operated by a normal cable.

And LHD's too. :wink:

gareth73 · **Posted:** Fri May 04, 2012 5:03 pm

turned out the stalling was the crank sensor,when engine got hot it lost its signal,changed it and my baby is fine again

anybody tell me where my lift pump is?

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