Rewiring your fuel pump [Merged 9-6]

[xveganxcowboyx]

My little input here is that if you have previous parts from a rewire on there, you'll want to remove them before doing a new rewire. No sense cluttering the problem.

 

[GTM]

I'm not sure where you're getting that you're having a problem with oil pressure....That will not keep your fuel pump from turning on.
...
Alternately, you can verify the voltage to the pump, but you'll need a friend to help you do this. Have a friend crank the car, and use a multimeter to check voltage at the wire coming from the battery (you can just touch the positive lead to the connector going onto the pin). You should be seeing approx. battery voltage here while cranking (usually 11.xx volts, or whatever your battery is putting out during cranking).

If no voltage shows up, you know you've hooked stuff up incorrectly.

Oil pressure switches (not sending uint) do fail and also can get unplugged. This circuit is bypassed in the crank mode _only_ but must be operational in the run mode, there are some designs which also will use the alternator charging in conjunction with the oil pressure switch. The down side to this design is the engine stopping if the alrernator fails or the belt breaks.

Depending on the car and with DSMs it is possible to reach under the intake manifold and unplug the starter solenoid then jam a small diameter screwdriver in the keyring hole of the key to hold in crank position while testing. I've also used ViceGrips lightly set on the key to hold it in crank mode for you can't always be bothering your buddy or coworker.

The down side to this is if the circuit design uses dropping resistors for normal run mode but bypasses them in crank mode thus running full battery voltage to coils and/or injectors etc for extended periods of time can run the battery down and harm components. So I limit the crank testing mode to about 10 minutes max before turning the key off and letting things cool down.
..........
If you know where/how the pump grounds that would be helpful.

Cheers,
GTM

 

[rustyoldsmoker]

Let me get this straight.. I should check the ground, the old connection might be bad.. Check voltage when i have the key on Start.... IF i choose to rewire with the stock pump, i'm not gaining anything except security of more power longer??

Prob just a fuel pump went bad if it just died after the fuel supply went low. I am just hackin this job i guess.. my technique was to put a remote wire to the relay to the fuse box in the car with a small fuse for the relay, and then put a wire from the relay to the battery and ground, then put a splice into the black and white pump wire..

And does anyone want to let me know what MPI is?? And where to find it, or is that the thing behind the battery..

Pump ground? I didn't think of where, i guess it would follow the harness up to the ecu or what ever is under my radio.. I hope i'm not boaring yall.. I am still learnin, and appreciate your help..

 

[femmeDSM]

The MPI relay is really 2 relays in one. One relay powers the MPI circuit (Multi-Port-fuel-Injection), and the other powers the fuel pump. It's a small gold box located behind the radio, next to the ECU. If you pull the carpet section from the passenger side next to the radio, you should be able to get to it.

If the MPI relay is bad, the fuel pump won't work. Even with the rewire, you are not bypassing the fuel pump relay -- it is still being used (that's what that black/white wire coming from your fuel pump goes to - no way to eliminate that).

As for the fuel pump check connector, there is a picture of it Here (just scroll about halfway down and you'll see it).

Once again, though, the connector is just a T off the MPI relay. So if your MPI relay is shot, this won't work either.

When you're cranking the car, you should be able to hear it Click on and off (on when you start cranking, Off about 1-2 seconds after you turn the key to Off)

If you feel like getting super enterprising, you can always verify that your fuel pump is operational the "long way". You can remove the fuel pump sending unit from the hatch, and apply (fused!) battery voltage directly to the positive terminal on the pump itself. Refer here for a visual: http://vfaq.com/mods/pump-WB-1GAWD2-print.html

If that doesn't do the trick, you can be pretty sure your fuel pump is toast. Again, this is the "long way", though

 

[rustyoldsmoker]

i guess i am going to just try to put a new relay in but not connect it to the old relay. I play to run the new relay to the back of the car and with power and ground, then just cap off the power terminal that came fromt the old one.. simular to the one of vfaq's. Except i will just run the remote button to where ever i need to push it or even maybe into the fuse box under the console.. wish me luck....

 

[DSMJim]

Honestly with a 255lph pump without it rewired you can make 400-450whp on a turbo car. You may make 500-550 with the higher fuel pressure, but honestly if your in that territory you will know enough to re-wire you car in which case your preaching to the choir.

 

[rustyoldsmoker]

So i rewired the fuel pump, and the clicking began, and thats where it ended.. I am not getting fuel, but both the old relay and the new relay are clicking.. but now i got wires running all over and i got to put them away to hide them.. I just got a 190lph pump of ebay for 92.05$, so that better fix the darn problem.. Now do i need a regulater for that??

 

[jepherz]

You can probably get away without an AFPR with that pump. Also, the fuel pump won't turn on until the CAS senses that the motor is turning.

 

[exiletalon]

If you have or are looking to get a 255lph, then at least an AFPR is neccesary. But with a 190lph, you are not required to operate an AFPR, however, any upgraded fuel pump is always recomended that you have an AFPR, even with a 190lph, I have an AFPR. It would not hurt to have a little extra room to tune, or watch your fuel pressure. IMO

 

[rustyoldsmoker]

So as the rewire is all done, i am now waiting for the pump to install. i'll begin later in the day spraying the lines with pb and hope for the best when its done.. What kind of afpr should i look into?? And i would say that i believe that the afpr is supposed to go before the fuel line on the fuel intake right??
Does anyone know if i can get a program to do the programing on my laptop computer in my car, i have seen the dsmlink for like 500 bills, but is there anything else or am i stuck getting a palm pilot.. And how do i tell what kind of rom i have, vs finding a rom that i would need for the link program?

I would also like to thank all that helped, you guys are great..

 

[Drifter27_04]

First I would suggest in getting in the fuel pump in and seeing if that solves your problem, and than lets talk about the FPR and what program would be best for your set up. Hate for you to go out and buy all this stuff and still cannot get it to crank. You can also get by w/o the FPR with the 190 fuel pump as mentioned in the above replies and from the looks of it you will be fine going with a Palm Pilot, but you would need something to tune the car with like a Apexi SAFC.

 

[rustyoldsmoker]

Safc?? not sure what it is and what it does. but i can research that one, i got a laptop, and am just lookin to see if i just need a cable and software..

It seems i mislead the group, the car is turning over, just want to enfasize that the clicking is the relay, letting me know that they are working after the rewire..

The tune part is unfamiar to me.. did you say i need a Safc for the tune?? I was wondering how i would change the tune.. so if there is anything that i can use to learn how to make all the adjustments when tuning that would be good, i'm a read-a-holic lately, all i do is read this information.. i just need to put it to use..

 

[Drifter27_04]

SAFC II:
http://www.apexi-usa.com/product_electronics_detail.asp?id=202&pageNum=1

If you are looking into tuning with you laptop you could install MMCD I believe there is a version for PC's than you can just get on eBAy and purchase the wiring you need to hook to your OBD port. But with the SAFC I dont beleive you would need the logging data but I am not for certian on this b/c never had the chance to mess with one, but for whats its worth I never seen a datalogger of some sort when someone has the SAFC installed. But if you really care to get into tuning through your laptop there are number of ways to do this like as in DSMLink but that will run you at least $550 and thats if you have a Socketed EPROM ECU.

 

[femmeDSM]

Guys, he is running the stock fuel pump. Please don't confuse him further by telling him that he needs piggy-back ECU controllers.

rustyoldsmoker: An S-AFC is an air/fuel controller that is utilized once people upgrade their fuel systems. Very basically, what it does is it "tricks" the ECU into allowing larger injectors (among other things).
There is NO WAY you are going to need any kind of ECU controller or ECU mods with the setup you're using (which is, as I understand it, basically stock).
The info that Drifter27_04 gave you was great - just not something you're looking for at the moment.

Suggesting a datalogger is always a good idea, so good job on that Drifter.

DSMLoggers.com sells a "complete" 1g datalogging kit that looks cool. Dataloggers plug into the diagnostic port on your car and let you "listen" to what the ECU is telling you. It's sometimes a much better way of locating problems than merely trial and error

 

[GTM]

So i rewired the fuel pump, and the clicking began, and thats where it ended.. I am not getting fuel, but both the old relay and the new relay are clicking.. but now i got wires running all over and i got to put them away to hide them.. I just got a 190lph pump of ebay for 92.05$, so that better fix the darn problem.. Now do i need a regulater for that??

Just for clarification, did you establish that there is 12v going in and out of the pump? Forget clicking relays for all that establishes is the relay coils are being activated but does not mean they are passing current _to_ or from the pump.

Once you get 12v there you then must establish that it's correctly passing through the brushes, the armature and out the grounding connection. It is imperative that your diagnostic work is not impeachable for it can make you look very foolish when you install that new pump only to have it not run also.

Since you are new here and have garnered some well qualified people it would be best to limit the scope of this thread to solving the immediate problem which is to get your car running. You can start another thread that deals with other concerns or modifications you wish to make.

It is common practice to give a suspect fuel pump a swift kick in the back side. Use a lead shot loaded hammer or a block of wood and give it a 2-4 smacks when in the crank mode. You may find the pump will start working again, needless to say it can no longer be depended on should that happen.

Cheers,
GTM

 

[Drifter27_04]

FEMMEDSM,

I agree totally with what you saying and thank you for the positive comment. If you look at the past few post of mine I did mention to say to fix the one problem he is dealing with now and than we could start on another in concerns of logging / tuning. I did not want to point him in the direction as it ended up to be as that I was under the impression he was still stock. More than less the information was meet for future mods and nothing more.

GTM...Since you are new here and have garnered some well qualified people it would be best to limit the scope of this thread to solving the immediate problem which is to get your car running. You can start another thread that deals with other concerns or modifications you wish to make.

I strongly agree with GTM.

 

[femmeDSM]

FEMMEDSM,

I agree totally with what you saying and thank you for the positive comment. If you look at the past few post of mine I did mention to say to fix the one problem he is dealing with now and than we could start on another in concerns of logging / tuning. I did not want to point him in the direction as it ended up to be as that I was under the impression he was still stock. More than less the information was meet for future mods and nothing more.

I completely understand that, and I'm sure everyone else did, as well. However, I (like GTM) think that we should all be concentrating our efforts on getting his car running before thinking about future plans for the car It's easy to go on for hours on end about what your plans are for a car "once it's running". I'm guilty of that, as well

I've found that taking things one step at a time is always the best bet, especially in problem diagnosis. It's too easy to get side-tracked and lose sight of the task at hand.

 

[psychlow]

All of these wisemen here, and nobody's noticed this:

So i rewired the fuel pump, and the clicking began, and thats where it ended.. I am not getting fuel, but both the old relay and the new relay are clicking..

This is one of the key signs of failed capacitors in your ECU. The MPI relay clicks on and off because the ECU goes into reset mode over and over due to a faulty power supply.

Pull your ECU and check the capacitors - make sure they're not leaking electrolyte on the board. I'm willing to bet a small sum of money that this is the cause of your woes.

 

[Drifter27_04]

Pull your ECU and check the capacitors - make sure they're not leaking electrolyte on the board. I'm willing to bet a small sum of money that this is the cause of your woes.

He mentioned the relay was clicking not ECU. That is if he is referring to the relay that is installed when rewiring the fuel pump (in the back of the car). ALso if he did something to his ECU he would have more problems than trying to crank it, I dont imagine he would here a click would he?

Correct me if I am wrong Wisemen.


Rustyoldsmoke....are you able to snap a few pics for us of your wiring? That way we can have a idea of what your looking at as well.

 

[psychlow]

He mentioned the relay was clicking not ECU.

The MPI relay clicks on and off because the ECU goes into reset mode over and over due to a faulty power supply.

The ECU energizes the coil side of the relay. If the ECU resets, the MPI relay clicks on and off because the ECU can't supply enough current to sustain the electromagnetic field in the coil.

One thing I do want to clarify though - I may have misunderstood by the "clicking" - if they click once when you turn key on and click once more when you turn the key off, they (and the ECU) are working correctly.

If they click in rapid succession while they key is on, then it may be the ECU as I suggested.

 

[femmeDSM]

Well, you could both be correct, really.
The MPI relay should be clicking ON when you start cranking, and OFF a few seconds after you turn the car off (or stop cranking).

I don't think any of us mentioned the ECU, since he clearly stated that his problem lies in faulty wiring to the fuel pump / MPI circuit. However, a quick inspection of the ECU is never a bad idea, as you suggested.

A quick way to determine whether your ECU is booting up (and this is a "just for peace of mind" check). When you turn the key ON, the Check Engine Light should illuminate for ~5 seconds, and your factory Boost gauge needle should shoot to "0".

However, back to the problem at hand.....Drifter had a good idea. Can you get a few pictures of the wiring? Can't hurt.

 

[femmeDSM]

One thing I do want to clarify though - I may have misunderstood by the "clicking" - if they click once when you turn key on and click once more when you turn the key off, they (and the ECU) are working correctly.

If they click in rapid succession while they key is on, then it may be the ECU as I suggested.

Correct. I assumed (as I'm sure others did) that the CLICKING was the MPI relay turning on during cranking and off when the car turned off. Maybe the original poster can clear this up for us once and for all

 

[GTM]

All of these wisemen here, and nobody's noticed this:

This is one of the key signs of failed capacitors in your ECU. The MPI relay clicks on and off because the ECU goes into reset mode over and over due to a faulty power supply.

First: I find it insulting read crap like this. Taking swipes at a collective group of people who are interested in problem solving certainly is not going to get you brownie points no matter _how_ right you may be.

Since I never claimed to be a DSM expert I would like to know from the original poster whether the "CLICKS" are from cycling the key on and off??? Or are they a rythmic occurance when held in the crank mode??????????

I think before we start condeming parts it is necessary to determine where the failure exists. If he hotwires the pump then the car should run. It is conceivable he has more than one failure but again we need to establish basics and I don't think that has been done.

Yet another question concerning diagnostics... what related circuits are activated when in crank mode and the _clutch_ is _not_ depressed??? Anyone?????

Cheers,
GTM

 

[femmeDSM]

First: I find it insulting read crap like this. Taking swipes at a collective group of people who are interested in problem solving certainly is not going to get you brownie points no matter _how_ right you may be.

Since I never claimed to be a DSM expert I would like to know from the original poster whether the "CLICKS" are from cycling the key on and off??? Or are they a rythmic occurance when held in the crank mode??????????

I think before we start condeming parts it is necessary to determine where the failure exists. If he hotwires the pump then the car should run. It is conceivable he has more than one failure but again we need to establish basics and I don't think that has been done.

Yet another question concerning diagnostics... what related circuits are activated when in crank mode and the _clutch_ is _not_ depressed??? Anyone?????

Cheers,
GTM

Everything he said is right on. You rock GTM

 

[rustyoldsmoker]

Alright, The answer your all waiting for... I hear the clicking..... when i turn the key on accessary( this is where i set up the rewire relay, attached it to a fuse for the radio) and as the remote push the toggle switch. I also hear a single click when i initially turn the motor over( the original relay under the radio) and the finial clicks are when i turn the key off they both click respectively as they are powering down. I have faith that the pump is getting power, but haven't taken the time to put power to the pump alone.. i'll go right now and snap some pics and try to hotwire it.. brb.. for another reply