i have a quick question here. i was replacing my fuel pump relay when i noticed that one of the wires was cut..so i looked around and most of the diagrams made it a 50-50 percent chance of me figuring out where it went. so im gonna ask you guys for some help. i have an 88 camaro s/c. the wires from left to right go Big Org, Small Org, Grn/Wht, Blk/Wht, then Wht/Tan. the small org wire is the one thats cut. the answer would probably take a lot of headache away from my situation. thx

 

Well, the fuel pump relay has normally the following colors: big orange, red, gn/wht, blk/wht, tan/wht.
So I assume that the wire that's cut is the red wire. It's the wire that goes to the fuel pump prime connector that allows you to run the fuel pump without the engine running. If it's cut, your car should still start and run fine, you just won't be able to for example purge all fuel from the gas tank using the paper clip trick.

Hope this helps.
Lou

 

thanks for the help. but i have another q. my cars starts up slow. takes a few cranks to start. i took it in a while ago and the said it was the low oil pressure cut off switch. they bypassed it and my car started right up. but when they did that i made my fuel pump run all the time. which killed my battery 2 days later. why did it make my fuel pump run all the time? and can i bypass it without it doing that?

 

Well, then it seems that it was a different wire that has been cut than I originally thought.

If your car takes a lot of cranking to start, that's definitely caused by an interrupted circuit between the fuel pump relay and the ECM. A clear symptom is if you turn on the ignition and the fuel pump does NOT whine for 2 seconds.

If some dipsh*t grease-monkey idiot short-wired your fuel pump oil pressure switch, he deserves to be shot. Go there and take your money back because that dumbass obviously doesn't know how cars work. Needeless to say, you should never go to that shop again.

For now, you can pull the 20A fuse by the battery, in the small black fuse holder (has an orange and red wire). That will stop the fuel pump so it doesn't drain the battery again. When you need to start it up, put the fuse back in, start it and drive it, then when you shut it off, pull the fuse again.

You can fix your cut off wire and make the relay work again which is the correct way of doing it. You'll need to find both sides of the cut wire and reconnect them (solder and heat-shrink tubing). Then you need to troubleshoot why they cut it in the first place. Maybe the relay was stuck closed and the fuel pump ran continuously. Or maybe an angry wife just wanted to take it out on the car or something.

In any case, I'm on AIM or Yahoo Messenger usually 8am - 5pm so you can message me and we can talk about it.

And please fill in your bio, like location, car, engine, etc.

Lou

 

well the oil pressure swich is reconnected. and its back to the slow starting. i think ur right about which wires cut and i dont think its the problem. the only thing that im really concentrating on is the slow starting. the people we took it to before thought it might be a problem with the ECM. but they eventually gave up cause they could find one that worked with my car. what do you think i should do about the interrupted circuit? replace the ECM?

 

If you fill out also your engine information, we could help you find an ECM. They are not that hard to come by. 305/350? TBI/TPI? V6 maybe?

I'm getting a little confused here by your symptoms.
Let's take it from the start. If you turn on the ignition (no starting yet), do you hear the fuel pump whine for 2 seconds? (the sound would be coming from the location of the gas tank).

We can get it solved, don't worry.

Lou

 

hm..so i went in a while ago turned the ignition on and listened. i dont think i heard it. im kind of a noob but i didnt hear anything from that area..just to make sure what am i listening for exactly?

sry if im rushing my questions here its just my dads getting all crazy about bypassing that low oil pressure cut off switch. he said since it worked before hes gonna try a different way, he says its not starting right away cause the oil pressures not getting up fast enough. i just want to do it right. find out what the problem is and fix it.

 

Sure, it's understandable you want it fixed soon. Especially after a grease monkey fiddled with it and screwed it up, dammit!

You were listening for a 2-second whine/buzz from the gas tank when you turn the key on. That's the fuel pump priming with ignition on.
If you don't hear it, then the wire cut on the relay was the wrong wire, dammit.

If you have a 12V test light or a voltmeter and at least basic knowledge or electricity, you can troubleshoot it yourself very easily.

Is your fuel pump relay oval shaped or rectangular? That makes a difference in the pinout. I'll post some instructions what to measure later today.

Lou

 

For future reference, you can find a lot of diagrams (including many special ones) on our ATGO page (AustinThirdGen.Org) in the Tech Article section HERE.

Now for some basic troubleshooting. If not done yet, remove the oil pressure grease-monkey-bypass so that your fuel pump doesn't run continuously. Put the 20A fuse back in the single fuse holder by the battery.

1) Take a test light and put the alligator clip on a good ground. Then pull off the fuel pump relay connector and test the big orange wire terminal with the test light. Does it light up? Good. If it doesn't, check the fuse by the battery.

2) Now stab the light into the terminal for the green/white wire. Go turn the key on. Does the light come on for 2 seconds? Good. If not, you have a problem in the wire going to the ECM (that controls the fuel pump relay).

3) Plug relay connector back in. Put your hand on the relay and yuor ear close to it. Have someone turn the key on. Does the relay click once and then again 2 seconds later? No, pull the relay out of the car, grab a hammer and have at it! Then go buy a new one for $10. (link here)

4) Put the test light on the tan/white wire (with the relay plugged in). Turn the key on. Does the test light come on? No? See solution to #3.

However, if the test light did come on in the last test but the fuel pump didn't prime, there's a wiring problem on the tan/white wire going down the harness to the oil pressure switch.

Let us know what you find out. But my guess would be that the relay is burned out. I'm curious how wrong I am.

Lou

 

i actually got a new relay in a few days ago and put it in. after i did it still had the problem..since i have a new one should i still go do the tests? oh and we removed the grease-monkey-bypass

 

Please, go ahead and perform tests 1, 2 and 4. That will tell us hopefully, where the problem might be.

Thanks
Lou

 

so i did the tests and the tan/white wasnt getting anything. so we gave it some juice to see what would happen. right when we did it we could hear the fuel pump going. my dads solution is to connect the org and wht/tan and put a switch that i have to hold to start my car.

all i see right now is that something is wrong with my oil system. cause my car wont start until the oil pressure flips the switch and when the switch is fliped it starts the fuel pump which then finally starts my car. all i can think of is that my oil pump is crap

 

There's nothing wrong with the oil pump. You can take the oil pressure switch off and throw it away if you wanted to, and the car should still run. It's only a backup to the fuel pump relay.

If you passed all the tests except for #4, change the fuel pump relay.

 

Apeiron is right, the fuel pump is ok. It always takes a lot of cranking to build up oil pressure. Then the switch finally turns on the fuel pump and the engine fires.

And as for the relay, spoop77 said he already replaced it, with no change.

So spoop77, you said you passed the tests. That means in #1 and #2, the test light lit up fine? That means you have power and signal to the relay. But you have no power FROM the relay. The last thing to test would be the ground then.

5) Repeat test #1 to make sure you have power on the first terminal, the thick orange wire. Put the alligator clamp on the thick orange wire terminal (12V source for the relay). Then use the tip of the light to touch any part of the chassis (bolt etc). It should light up. Now touch the black/white wire on the relay connector. It better light up. If it doesn't, you have a bad ground and that's why the relay isn't working.

Let us know. I'm very curious now.
Lou

 

i went in awhile ago to check if the ground was working and it was.

 

Ok, last question to ask is: does the relay click when you turn the key on?

Because it has power, it has ground, it has signal from the ECM, it's a new relay, yet there is nothing on its output. Then it could only be the connector itself. Dirty, rusty, or otherwise a bad connection. We covered everything else.

Lou

 

i went to check to see if i could hear the relay click. i had my friend turn the key and i didnt hear the click

 

So if you say that all the wires at the relay connector are alright, then it could only be the connection to the relay. Do any of the pins in the connector look bent, damanged, deformed?

Another check also would be to put a voltmeter on the ground wire (black/white) on the connector with the relay plugged in. It should read 0V. If you turn they key, the voltage shouldn't change, it should still read 0V (or very close). If it reads some voltage when you turn the key (the first two seconds), the ground is not good.

Let us know.
Lou