Rewiring your fuel pump [Merged 9-6]

[steve]

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

The clutch safety switch grounds the coil of the starter relay causing the relay to activate and disconnect the ignition switch from the starter solenoid. The result is that the relay clicks and the car doesn't crank. I forget off the top of my head if the connection between input to the fuel pump side of the MPI relay is to the power or control side of the starter relay circuit.

Steve

 

[GTM]

Everything he said is right on. You rock GTM

For a girl (woman) you "ain't" so bad yourself. (intended as a compliment) Your vocation and avocation certainly are a contrast. I have had the honor of training 2 women to be mechanics, 1 left the profession after marriage and I lost contact with the other when I changed products.

Hopefully you will not be put off with my sometimes subjective quip as told to me by an Argentine customer: "Cars and women, joys and sorrows."

I'm sure I still could equal J. Mitchner in writing repair manuals, what bothers me is the things I've forgotten over these decades.
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Under no circumstances should any Wiseman/Wiseperson be subjected to insults. Most of us have paid our dues to earn the designation and none of that came free from mistakes. It is important to remember to not spend any member's money with incorrect diagnosis thus comes the creative process of developing tests, concepts, ideas which will contribute to a solution without spending hours and $$$. None of us have all the answers and it is possible to get snookered into going down the wrong path when others offer viable constructive help.
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Having read ahead I see a disturbing situation by the original poster. He has wired a relay into the radio, unfortunately this is bad practice especially here for when the key is turned to crank mode many radios will drop out of the circuit so as to get max crank amps to the critical start components. The poster admittedly is a novice yet is giving it his best, we need to make sure he is on the right track and his test procedures are valid.
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If a spare battery is available it may prove to be quicker to disconnect all the wires from the fuel pump and then with jumper cables ensure the pump is able to run. If not condem the pump, if yes then more extensive testing to eliminate the failure(s).

Cheers,
GTM

 

[rustyoldsmoker]

i went and took pictures and i'll post them, as far as the radio goes, i only used the fuse as a remote to the relay, the power is straight off the battery. i just cant figure out how to show the pictures

 

[femmeDSM]

i went and took pictures and i'll post them, as far as the radio goes, i only used the fuse as a remote to the relay, the power is straight off the battery. i just cant figure out how to show the pictures

If you like, you can e-mail me the pictures and I'll post them up for you.

I'll PM you my e-mail address.

 

[femmeDSM]

For a girl (woman) you "ain't" so bad yourself. (intended as a compliment) Your vocation and avocation certainly are a contrast.

Thank you I'd love to be a mechanic by trade. Unfortunately I'm stuck here in the executive world, and can only use my mechanical skills as a (rather time-consuming) hobby.

It is important to remember to not spend any member's money with incorrect diagnosis thus comes the creative process of developing tests, concepts, ideas which will contribute to a solution without spending hours and $$$. None of us have all the answers and it is possible to get snookered into going down the wrong path when others offer viable constructive help.

Words to live by. I couldn't agree more.
I always like to take the route of "fix the free things first". It's easy to fix problems when you have an unlimited budget at your disposal, but unfortunately that is rarely the case.

Having read ahead I see a disturbing situation by the original poster. He has wired a relay into the radio, unfortunately this is bad practice especially here for when the key is turned to crank mode many radios will drop out of the circuit so as to get max crank amps to the critical start components. The poster admittedly is a novice yet is giving it his best, we need to make sure he is on the right track and his test procedures are valid.

I missed the part where he mentioned wiring the fuse into the radio. You bring up an excellent point. Once again, I think pictures will help us steer him in the right direction. Unfortunately in cases like this, it is all too common to find it difficult (or near impossible) to render good advice when we can't physically see the car in question.

rustyoldsmoker: You are on the right track, and we all commend you on your efforts Hopefully we can get this worked out with you

 

[rustyoldsmoker]

Dial up is slowing this down, but patience is the virtue.. I did want to add that i took the power connection from the new relay(that is from the battery itself) and touched it on the power to pump wire, and nothing happened.. no sounds what so ever.. i didn't however measure the voltage on these lines.. i have a multimeter now, so i can do that later..

 

[GTM]

i went and took pictures and i'll post them, as far as the radio goes, i only used the fuse as a remote to the relay, the power is straight off the battery. i just cant figure out how to show the pictures

I'm not sure the picts will be of value if you are comfortable you have done the temp rewire correctly.

Okay, when the relay is activated do you have 12v to the pump _and_ out of the pump? If you have a good ground you may not see any voltage on the negative side of the pump. If you disconnect the negative side you should see 12v. If you ground the pump it should run. I use 12v as meaning battery voltage so let's not mince words over 12v or 13.2v. If you don't have a DVOM (digital volt ohm meter) then a test light can be used for probing the circuit. It will light on the positive side of the pump, it will light on the negative side if the ground is disconnected OR you have an open circuit on the ground side. It will not light on the ground side if you have a completed circuit to ground.

These are absolutes, no if and buts about it, the pump must run.
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You can buy inexpensive tools from Harbor Freight, (harborfreight.com) DVOM/DVM on sale for $4-$6, test lights $2-$4... over $50 and free shipping if that is an issue.

This is a DIY board, if you are going to continue then try to get some basic tools so you can effectively do proper diagnostics so we can help you. I don't mean to be be harsh, crass, nor demean your efforts but you have to trust that some of us are more than qualified to solve this problem if you follow directions rather than running helter skelter. These tests will take no more than 5 minutes of your life but are critical in getting the answers you want.

Cheers,
GTM

 

[femmeDSM]

Well...For what it's worth, take a look at these pics.

I can offer more help in a bit. I'm off for the moment though.

 

[rustyoldsmoker]

Thanks femmedsm, the pics are great, i really appreciate it.. so i'm going to go and change the relay remote wire to connect to the original relay. and i am bringing a multi-meter and also a battery jumper pack. I will change the "switch" so its not shuting off during cranking... checking voltage too.. will post asap.. like 30 min from now..

 

[rustyoldsmoker]

Ok, what a headach. I got readings from relays before they would kick off, when i probed the possitive to pump wire from the original relay for power after the click(meaning power is now active in the relay), i did see power when i grounded the negative prob into the hatch. This would leave me to believe i have power to at least the second relay as it would turn the rewired relay on.

i got a full 12v reading (on the new relay while it was off) at the ground, remote and pump wire when using battery input wire for charge(the new wire used to power the pump.) . IMO this would show a complete curcuit.

I got a 12v signal when i probed the pump wire while cranking over the engine for 10 seconds at a time, then takin a break for a minute and retrying. I believe that the pump is shot. If anyone has anything else i would be glad to check anything.. but the pump stays in until i got the new one to work with..

 

[psychlow]

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.

WHOA WHOA WHOA! - there were no insults intended here!

You guys are the the reason this community is what it is, so I wasn't attempting to fling mud or put down anyone here. I was just surprised that it wasn't mentioned, and it turns out that it was because I was reading it differently than you guys were, and you guys were right.

rusty, you may be able to get the thing to start if you pull the pump and make sure all the connections are secure. You could even try energizing the connections directly (AWAY FROM THE GAS TANK) to make sure that the pump is 100% to blame.

Since it's not going anywhere in the meantime anyway, couldn't hurt to pull the pump now. Just a suggestion though.

 

[femmeDSM]

rusty, you may be able to get the thing to start if you pull the pump and make sure all the connections are secure. You could even try energizing the connections directly (AWAY FROM THE GAS TANK) to make sure that the pump is 100% to blame.

Since it's not going anywhere in the meantime anyway, couldn't hurt to pull the pump now. Just a suggestion though.

GTM and I both suggested that a while back. I think that's the best thing to do at this point, since my bet is that the pump is shot anyway (like you said)

Just run that fused jumper wire to the positive connection on the fuel pump itself, and run a ground wire from the negative post. You should be able to tell by looking at the pump which wire is positive and which is ground - it's pretty obvious.

That'll show you once and for all what's going on with the fuel pump.

 

[rustyoldsmoker]

Thank you all, and i will be testing the Fuel pump.. I did want to remind all that i am awaiting a walbro 190lph i ordered on ebay. two days ago. Can't wait for it.. Just a question about a 14b, i vagely remember reading that your not supposed to run them up to 20psi.. but the one i bid on seems to have been run around 20psi, i will probably get a junk if thats the case right??

 

[femmeDSM]

You have a Non Turbo motor in an AWD car, which is super weird in itself...Out of curiosity, did you buy the car that way? Or what...?

Anyway.
I assume you're ordering/piecing together a turbo kit for it? There is a lot of work to be done if this is the case. Non Turbo motors can be turbo'd (many people around the forums have done it) but I'm sure they'll all tell you that it's not the easiest or quickest task

As for your question, though: I wouldn't recommend going over 14-15 psi on a 14b turbo with stock 450cc injectors, for several reasons. Throw on some aftermarket injectors and SAFC and you can turn it up to about 17 psi. I wouldn't do much more than that on the 14b though. I'm sure others have accomplished it, but I err on the side of caution.

I'd recommend researching everything you're planning on, and making a list of supporting mods that are needed to run whatever setup you're planning on. DSMTuners has a great Tech Guide section that discusses staged upgrade paths at great length... Check it out

 

[rustyoldsmoker]

Alrighty then, I would like to say that i did purchase my Dsm from a co-worker. The car has adjustable struts, slotted disks on the frount and many small bruises. The car wears a plaq on the drivers visor that says it won a covered bridge rally race, and the previous owner said he heard the owner before him did race it.. So the car has some wear on it and lots of folder paperwork on replacements.(shafts, timing belt, oil, vibration..etc)
The turbo let a seal free with my attempt at rushin down an open road.. prob on the throttle too long, no shaft play but smokes alot.. So i took it out and put the cold air intake with a tube manifold. I wasn't to sure of it working, but when i turned the key and put the last clamp on the exhaust(which is the worst hack job i would say.) She ran like a champ, and the only part i lost power in was the mid-top end. she ran good, very very loud, with a non-resistent muffler. She is my pride and Joy, and you guys are my new family, where have you been all my life DSMers, I love you guys..sniffle sniffle so here i am fixin the next problem that arose, and with all your help.. Any questions, let me know..

 

[GTM]

WHOA WHOA WHOA! - there were no insults intended here!
You guys are the the reason this community is what it is, so I wasn't attempting to fling mud put down anyone here. I was just surprised that it wasn't mentioned, and it turns out that it was because I was reading it differently than you guys were, and you guys were right.

rusty, you may be able to get the thing to start if you pull the pump and make sure all the connections are secure.
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Since it's not going anywhere in the meantime anyway, couldn't hurt to pull the pump now. Just a suggestion though.

I'll take that as an apology. I think there were other ways of expressing your original thoughts on the subject. The old mantra of "look before you leap" might have been applicable and certainly this thread has had plenty of that which has had Rusty~ running in circles not knowing who to trust.

Working under the umbrella of a dealership there are a plethora of unproven tests that with reasonable care can be performed including testing the fuel pump.

I had suggested giving the pump a few smacks with a soft hammer or a wood block which will sometimes jog the brushes into contact with the aramature. Brush contact is probably the most common internal failure; however; rapping on the gastank is much less effective when the pump is inside. You can do this with power applied more effectively than static and applying power. On the outside chance it does start/ restart now would be the opportunity to move it to a better location if needed.

Whenever doing diagnostic work it is prudent to reduce things to their lowest common basic testing and then the easiest tasks first though location and commonality may alter some of this. It is sometimes helpful to sketch out in crude schematic / block form what needs to be done and then check off those tasks so you don't have to duplicate them. It sometimes is helpful to work a circuit backwards particularly when the electrics involve many conditional branchings which can have you off in the wrong direction.

Rusty~ I would like to encourage you again to start another thread for un-related questions. It's not fair to you and those who have their brain geared for solving this problem. Modifications come under another forum where you will find plenty of help from those who have been there and done that. Living in Ca. and working for dealerships most of my life they take a very dim view of violating smog laws thus I know little about them.
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I may be off line as I set up a rather complex scsi raid system for my 20 drives arrived today.

Cheers,
GTM

 

[rustyoldsmoker]

Sorry for the unrelated posts. I am still waiting for the Fuel pump.. i wil get back to posting when i get the pump..

 

[rustyoldsmoker]

So, last night i got the fuel pump via UPS. Thanks guys. So i did the usual, wait til the kids in bed, then finsh dinner, and go out to work on the car... Well... I did as many have suggested, i made the pipe fittings and bults to the fuel pump doors very very wet with pb blaster.. This would come to be a Extrem Possitive to getting this done with no disruptions.. I then read the pictures on the install sheet, words mean nothing. .. i've done my homework and had great teachers.. I had no problems unbolting the fuel line, no problems taking the bolts off the trap door.. So i would say that everything went according to plan.. I pulled out the pump, and after fighting with the thought i would strip the first philips screw on the bottom of the retaining bracket, i just clamped on it with a good old set of vicegrips.. good thinking... well the only problem i came to was grouding the new walbro pump, i used the eye ring for possitive on the old connection on the underside of the pump door. the negative screw in the bracket was A nightmare.. i just cut and butt connected the wires with a shrink wrap butt connector.. (shrink wrap the connector over the fuel tank with bic lighter) (brave soul) anyways, i got the fuel pump changed with no problems, cleaned up, put the tire back.. close the hatch, put jumper cables on, and no start. ahhhhhhhhhh... i could hear the pump come on with an odd sound, which to a new owner of this particular pump, i would imagine is the normal sound, The first couple of cranks, the pump sounds good, then i didn't hear it, and the charge on the battery was stronger so i got more cranking, so i'm going to try to vent some air out of the line on the filter and see where that gets me, but let me tell ya, i wasnt' the happy camper i intended to be... Any other thoughts, holla at this boy.. I could use a little help..

 

[Drifter27_04]

Sorry to hear the bad news.....Are you having the same problem as before or is it doing anything other different?

 

[rustyoldsmoker]

so far same problem, need to check and see if any fuel is getting to the filter though. I got pissed at the fact it wouldn't run, so before i broke something, i decided to go home and sleep on it.

 

[Drifter27_04]

Yeah know how you feel when things dont work out the way you hope for.

Mentioning the filter, if I can recall throughout this thread I dont think anyone has mentioned the fuel filter. You might want to install a new one. Since you did mention before that the car was in a rally race we may want to investigate the filter as it maybe clogged up and not letting much fuel to pass through. We can only assume also that the car was not just in one rally but several. This is only assuming that you have not yet check or replace the filter but if you did neither I would do so just for ease of mind. You my also would ask the person you bought it from if he change it just to save you the time and money.

 

[femmeDSM]

Sounds like one of three problems going on.

1 - MPI Relay or related wiring is shot.
2 - Faulty Installation of the Fuel pump, or a bad ground on the rewire.
3 - Blown Relay from the rewire

What you can do now is verify (once again) whether the new fuel pump will turn on. You should have a fuel pump check connector behind the battery on the firewall. (There are two connectors here - the larger one is the ignition timing plug, the smaller is the check connector you're looking for). I can post a pic of it if you need me to.

Run a fused jumper wire from the positive battery terminal to the check connector. If you do not hear the pump turn on at this point, you've found the problem. Since you can be *almost* 100% sure that the problem is not with the pump itself, that would leave the MPI circuit as the likely culprit.

For now, you can double check the fuel pump installation and the rewire. Check all grounds, and verify that the power wire from the battery to pump is receiving proper voltage.

To check the relay, you can connect pin 30 to pin 86. You should hear the relay activate (click), and you should now get ~12v at pin 87.

Try this and get back to us.

A fuel filter is always a good thing to check and replace. But I don't think this is the particular problem here. This is likely electrical.

 

[rustyoldsmoker]

I am going to check into the filter by means of weather fuel comes out when hose is removed.. I will check the electrical parts as well by monitoring the output of 12v at all circuts and get back to ya..

 

[GTM]

I am going to check into the filter by means of weather fuel comes out when hose is removed.. I will check the electrical parts as well by monitoring the output of 12v at all circuts and get back to ya..

so far same problem, need to check and see if any fuel is getting to the filter though. I got pissed at the fact it wouldn't run, so before i broke something, i decided to go home and sleep on it.

I need to know if you tested both pumps once removed to determine if they ran????

I need to know if you inspected and tested the dip (pickup) tube and filter to see if they would pass air???

Perhaps someone can comment if there is a check ball in the pickup tube.

Remove the fuel filter and blow air _backwards_ through it, catch the fuel in a clean can for particulate inspection. You may re-use the filter if you don't have a spare.

Blow air through the fuel line from the outlet side of the filter towards the engine with the line removed at the fuel rail on the engine. Throw a towel over the end to catch the fuel.

Post your findings here.

Cheers,
GTM

 

[GTM]

Sounds like one of three problems going on.
...

2 - Faulty Installation of the Fuel pump, or a bad ground on the rewire.
...
What you can do now is verify (once again) whether the new fuel pump will turn on.

As of this post I have yet to confirm that rusty~ has properly applied power to the fuel pumps and had them run either on or off the car.

Maybe he needs to know he won't get electrocuted with 12v. On occasion you can get a small shock from testing a relay as a coil collapses it's nothing more than an annoyance.

I do now perceive that the car is not near the computer thus reporting back with results has problems. I would strongly advise that he should print out our questions take them to the location and then perform those tests. He can then write down the results and properly reply.

I just don't think we are getting a clear picture of how he is going about this and we are spinning our wheels because of incomplete testing. This is not meant to be insulting but something is just not adding up. Maybe there is another member near him that could lend a hand with this...

Cheers,
GTM