delco ep375 fuel pump question
Thread Starter
Cruising
Joined: Sep 2011
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delco ep375 fuel pump question
I just aquired a 91 automatic with 71000 miles. I 've searched this forum for months and hav'nt had to post a new topic until now. I was trying on the highway when the car suddenly shut off and would not restart. I assumed it was the fuel pump because prior to this incident, I ran out of fuel.
.I purchased a ac delco ep375 as requested by my local shop. My question is there is a tiny rubber plug on bottom of the pump were the strainer goes. Iam I suppose to remove before installing?
.I purchased a ac delco ep375 as requested by my local shop. My question is there is a tiny rubber plug on bottom of the pump were the strainer goes. Iam I suppose to remove before installing?
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
I just aquired a 91 automatic with 71000 miles. I 've searched this forum for months and hav'nt had to post a new topic until now. I was trying on the highway when the car suddenly shut off and would not restart. I assumed it was the fuel pump because prior to this incident, I ran out of fuel..I purchased a ac delco ep375 as requested by my local shop. My question is there is a tiny rubber plug on bottom of the pump were the strainer goes. Iam I suppose to remove before installing?
.I purchased a ac delco ep375 as requested by my local shop. My question is there is a tiny rubber plug on bottom of the pump were the strainer goes. Iam I suppose to remove before installing?
Thread Starter
Cruising
Joined: Sep 2011
Posts: 12
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Its on the fuel pump itself. I should of took a pic before installing....... The car is cranking but not starting up. I hear the pump turn on and there is fuel at the rail. I sprayed starter fluid in the throttlebody and it started up. Any thoughts.
Instructor
Joined: Jun 2011
Posts: 182
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From: Bowling Green Ky
when I read the post, "suddenly shut off", I thought it was ignition, not fuel. when fuel runs out, it is a violent death, versus sudden.
if you have fsm, start at chart A 3, "cranks won't run." if it does run with fluid, you will go to pg 2 of the chart to check injectors. an over-rich conditoin could cause almost same symptoms. have you/can you pull any codes?
Thread Starter
Cruising
Joined: Sep 2011
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No I cant pull any codes because I dont have a code reader for this car. But iam going to purchase a fuel pressure guage today. What are the more common things damaged when running out of gas, aside from the pump
Instructor
Joined: Jun 2011
Posts: 182
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From: Bowling Green Ky
most people pull codes by jumpering terminal a-b in aldl- assembly line diagnostic link. if all that is greek to you, it is in the fsm, or any manual most likely.
not aware of damage by running out of fuel. nada.
stupid question: what led you to conclude that old pump was the problem? without some diagnosis, you are going to be floundering.
Thread Starter
Cruising
Joined: Sep 2011
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Thanks the a-b pulled a 12 code which i believe is no error but I have disconnected the battery since the problem. not a stupid question but a stupid assumption on my end. I jumped the gun without even checking if the pump was not working. I almost ready putting it at the hand of a mechanic.Iam just running impatient becuase the car is in a bad spot in my driveway and this car took me on numerous trips from NY to PA without a problem. I will keep looking on the forum because i know the answer is here. GREAT forum
Instructor
Joined: Jun 2011
Posts: 182
Likes: 0
From: Bowling Green Ky
Thanks the a-b pulled a 12 code which i believe is no error but I have disconnected the battery since the problem. not a stupid question but a stupid assumption on my end. I jumped the gun without even checking if the pump was not working. I almost ready putting it at the hand of a mechanic.Iam just running impatient becuase the car is in a bad spot in my driveway and this car took me on numerous trips from NY to PA without a problem. I will keep looking on the forum because i know the answer is here. GREAT forum
it starts, so likely not a spark issue. you can verify if plugs are wet.
if you hear the FP when key ON, check schraeder valve on fuel rails. engine will start on 20 lbs pressure. if you have fuel, it may not be getting to/past the injectors. of course, you have checked fuses?
or it may be flooded, or ecm sees inputs that it is. example, for CTS, coolant sensor, but should set a code 14 I think. also check vac line at fuel regulator for fuel.
unhhook TPS and crank, also MAF. all easy to do to get a reaction.
hold throttle open while cranking. also watch tach, rpm means pulses from distr to ecm. if you follow FSM it will lead to injjectors, checking resistance of each, ckecking for blinking light, etc, several pages of it.
Last edited by stoydido; Sep 10, 2011 at 01:24 PM. Reason: spelling
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Instructor
Joined: Jun 2011
Posts: 182
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From: Bowling Green Ky
starter fluid can overcome rich condition also.
you have MAP, easy to unplug to chk for reaction.
if you "conclude" that it is injector pulses, or injectors, fsm suggests unplug each one, cranking, to isolate the problem.
no doubt I have missed some things but fsm is your guide.
8th Gear
Joined: Jun 2011
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Found out it was the opti spark. Just replaced that (what a pain) I also found 3 fuel injectors that had carbon so I replaced those. It's running rich now. I am assuming the fuel pump is going out because the fuel pressure isn't high enough causing the injectors not to spray a mist.
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
Same thing happened to me. At first I thought it was the fuel pump as well. I then found out that it was a blown fuel pump relay, one of two on the car. After I fixed that, it was back firing into the intake manifold!!! Found out it was the opti spark. Just replaced that (what a pain) I also found 3 fuel injectors that had carbon so I replaced those. It's running rich now. I am assuming the fuel pump is going out because the fuel pressure isn't high enough causing the injectors not to spray a mist.
Found out it was the opti spark. Just replaced that (what a pain) I also found 3 fuel injectors that had carbon so I replaced those. It's running rich now. I am assuming the fuel pump is going out because the fuel pressure isn't high enough causing the injectors not to spray a mist.never heard the "mist" thing before. if pressure was that low, it would not be running, my guess.
joe
8th Gear
Joined: Jun 2011
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the 2nd relay if for vin j engines. I assumed he has FP working off the relay, else he would not be able to prime it for 2 secs. my experience is you have to really be listending to know for sure if the relay is running the FP or if the abs is clicking.
never heard the "mist" thing before. if pressure was that low, it would not be running, my guess.
joe
never heard the "mist" thing before. if pressure was that low, it would not be running, my guess.
joe
It has new plugs, wires, opti spark, 3 fuel injectors, timing and compression checked.
What is the fuel pressure suppose to be at? I have had a mechanic tell me around 40 and my family mechanic said it should be around 70-80 psi.
Instructor
Joined: Jun 2011
Posts: 182
Likes: 0
From: Bowling Green Ky
Then what would be the possibility for the car running rich?
It has new plugs, wires, opti spark, 3 fuel injectors, timing and compression checked.
What is the fuel pressure suppose to be at? I have had a mechanic tell me around 40 and my family mechanic said it should be around 70-80 psi.
It has new plugs, wires, opti spark, 3 fuel injectors, timing and compression checked.
What is the fuel pressure suppose to be at? I have had a mechanic tell me around 40 and my family mechanic said it should be around 70-80 psi.
rich can be faulty coolant temp sensor, would set a code. maybe TPS, also o2 sensors -maybe. I am not experienced with o2 sensors. but fuel presure isn't in the list. on l98, the FPR, fuel regulaor can lk into vac line.
how do you know it is rich? should set codes.
8th Gear
Joined: Jun 2011
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90 fsm says 37-44 I think, don't have it here. your mechaninc is half right.
rich can be faulty coolant temp sensor, would set a code. maybe TPS, also o2 sensors -maybe. I am not experienced with o2 sensors. but fuel presure isn't in the list. on l98, the FPR, fuel regulaor can lk into vac line.
how do you know it is rich? should set codes.
rich can be faulty coolant temp sensor, would set a code. maybe TPS, also o2 sensors -maybe. I am not experienced with o2 sensors. but fuel presure isn't in the list. on l98, the FPR, fuel regulaor can lk into vac line.
how do you know it is rich? should set codes.
Any advice would be much helpful.
Instructor
Joined: Jun 2011
Posts: 182
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From: Bowling Green Ky
the exm uses the temp sensor voltage returned by the sensor that is altered by resistance of the sensor, and adjusts fuel "ratio" accordingly. among many other things.
if the sensor shows cold on hot engine, more fuel.
don't ask why the dash gage does not show cold. I knew, but forgot. doesn't matter.
you maybe should start another thread and get some action.
first question is: are codes set?
Last edited by stoydido; Sep 12, 2011 at 03:54 PM. Reason: added*
Thread Starter
Cruising
Joined: Sep 2011
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Ok finally bought a fuel pressure gauge. When turning the key in on position I get 43 psi . The only way the car starts is if I spray starter fluid in the intake. I can then keep it running by gasing it in high rmps. Ha soon as i let my foor off the gas it dies and wont restart. I have the fsm and its german to me.
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
Ok finally bought a fuel pressure gauge. When turning the key in on position I get 43 psi . The only way the car starts is if I spray starter fluid in the intake. I can then keep it running by gasing it in high rmps. Ha soon as i let my foor off the gas it dies and wont restart. I have the fsm and its german to me.
does it now show codes?
is the exhaust rich/blk?
it has spark and fuel but not in the right quantities.
it was suggested that you unhook tps, start engine, look for a reaction. if no improvement, reconnect, unplg MAP sensor, start, look for reaction. these sensors won't always send a code.
someone may be thinkiing more clearly, but I would look for clues if mine.
Thread Starter
Cruising
Joined: Sep 2011
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Only code I pull is a 12. I just tried replacing the map and no luck. I'll go an exchange it for a tpi . I have nothing to loose. But keep in mine I cant start it without starter fluid.No black smoke when it is running
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
also, check the fsm for "cranks, won't run," chart a-3 to start with. the book says to hold throttle WO while cranking in case the ecm senses a flooded engine. if it starts without fluid, ecm may be shutting down injectors during start.
&&& add: you did inplug TPS? it now sounds like runs -won't idle issue.
Last edited by joe paco; Sep 21, 2011 at 05:04 PM. Reason: &&&