OK so I been reading tons of forums and decided to ask a few final questions here.

short story: so after jacking the car up and taking the rear muffler off and welding a few parts and putting it back on. the car wouldnt start yesterday, cranked and cranked and never would completely turn over. so i thought was low on fuel, put a gallon in, and the same happened. checked battery terminal and the negative one was slightly loose, so tightened it down and voila! car started like normal.

so drove to gas station filled up and when i went to start it, same issue. cranks all day but never starts.

I tried replacing the main relay/fuel pump relay with a new one from advanced auto parts and that didnt fix it.

here are the questions: when i put the key to ACC selection the CEL light comes on for about 3 secs, then i hear the click of main relay and the CEL goes off. is this normal??

i dont hear the fuel pump priming, i took off the driver side (which i believe is input line) lead on the fuel filter and tried starting it and no fuel came out. so if i'm correct the fuel pump is not pushing any fuel right?

If i replace the fuel pump with a Walbro 255 will my car run rich?

I believe its either the fuel pump is bad or the connects are corroded b/c the problem seems to be intermittent.

 

I've also seen that it could be the ECU went bad. I have a JDM auto p30 that came in the car when i bought it, the ECU was modded to work on a manual so its OBD0 i believe (I'm new to the tuning world) thats why i bought the car to learn. is there any way I could test or easy way to know if it is the ECU without just going out and buying a new one and putting in the car? my friend told me to look on the ECU for blinking red light but my ECU doesnt have one... i think b/c its JDM correct?

 

Have you disconnected the battery before doing any welding on the car? If not, you might have damaged / short some wiring or the ECU. The CEL light should go off after 2-3 seconds on the ACC, so it's normal. The pump only primes for a second or two just to push enough fuel to the fuel rail for an engine to start, so it's normal that you don't hear it priming continously after turning the key to ACC mode. Open the gas tank doors, take the cap out and ask somebody to turn the key to the ignition, you should hear it prime for a second or two if you listen close enough to the gas tank filling pipe. If you don't hear anything then either the new relay is also dead or you need a new fuel pump. An easy way to check on the pump is to take two wires straight from the battery and give 12 volts to the pumps plug under the rear bench seat/cargo storage. New parts not always mean that they are good ones, especially non OEM. good luck

 

#1 This is normal.
#2 you need to grab a multimeter and find out if you are getting power to the pump.
#3 not good.see #2^
#4 you shouldnt,but it will boost fuel pressure.

based on your story though,sounds like you need to clean your grounds up.that means REMOVE/THOROUGHLY CLEAN/REINSTALL

 

ok i purchased a multimeter yesterday also, so where should I test the fuel pump to make sure its getting power? the harness under the trunk carpeting in between the hatch the the front seats? at the silver metal dome in the center of the car?

and I know the pump only primes for a sec or two but i dont hear anything and i turned the key back and forth like 30 times yesterday lol. I'll try the ear up to the gas tank inlet today but I'm doubtful I will hear anything.

and I welded the muffler with it off the car. so no chance of messing up any wiring when doing that.

 

when you jacked it up dirt at the bootom of your tank could have gotten into your fuel lines. When you got it started did it cut out ? or did you have it running long ? clean your fuel lines would be my theory

 

no didnt cut out, just after i turned it off it wouldnt start back up. and I do have a weird issue where when the car gets down to quarter tank of gas, if I go around a corner fast, the car loses power like no fuel then when it straightens back out it gains power again. I figured the gas gauge was just off by a quarter tank b/c the previous owner installed indiglo guages so he might have messed up the gas guage?

does the turning lose of power seem like low fuel?

 

unbolt the main relay and hold it in the hand before turning the ignition on. it can be easily felt if it turns the circuit on or not with a click noise. if it does that,then, as I mentioned before, get to the fuel pump wiring in the rear, this will be the easiest way to check the pump. unplug the pump from the main loom and give 12 volts to the positive terminal of the plug, ground to the negative. if you won't hear the pump spinning, then you found your problem. don't forget to try this both with your old main relay and the new one, just in case one of them is faulty.

 

by the way, I had a very similar issue with the pump on my EG Civic, the pump was half dead and was not priming enough fuel to the engine, it did not start well and it did not run well even tough I heard the priming noise. It died completely after about 2 days.

The golden rule is always to put enough fuel in the tank before doing any other major repairs. Also don't forget, that all the nasty stuff that comes with the fuel stays on the bottom of the tank, so if you run out of fuel the pump takes all that stuff to itself and sends it to the lines and fuel filter. If you have never ever changed the filter it might be worth taking a look at it as it's not a pricey job to do and might save your time.

 

I had it running enought to drive about 4 miles to gas station before turning it off again. so about 5 min drive.

so what I plan on doing is checking the pump by doing the wires from the battery straight fuel pump connector in trunk of car like the other user suggested. thank you for all the help guys, i'll let u know how it goes

 

Fuel pump for sure

 

yeah the filter looks like it was never changed, so going to try that either today or tomorrow and see what happens. any suggestions on which filter to get?

the engine has a b16a in it, so not sure if that requires a different type of fuel filter compared to the original CRX HF motor??

 

you are running around in circles if you listen to everyone at once and dont make a move..it is much easier to diagnose something if you start somewhere.


unplugg the fuel feed line from the fuel filter and crank,does fuel come out?if yes,plug it back in and do the same thing for the fuel out line.if it doesnt come out of that,then replace the fuel filter.

if you did both of those tests and cant get fuel to come out of either one,grab your multimeter,pull the back seat out and test to see that the fuel pump is receiving 12v.if it is receiving 12v,then your fuel pump is faulty.

if it is not receiving 12v,try the jump test and give power to the pump from the battery at the same place you tested for power.you should hear a whirring(fuel pump priming).if you do not,then you just confirmed that the fuel pump is bad.

UPDATE AFTER YOU DO THIS.

 

ok so i turned the key to the 2nd position where all the lights come on in the dash, the main relay clicked like normal and no fuel pump prime. I used my multimeter and I was only able to get voltage from one wire on the wire harness that is connected under the trunk tool box area behind the front seats.

6.7 volts from the yellow wire

 

bump... so 6.7 volts to fuel pump what's that mean?


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is 6 volts to a CRX fuel pump normal?? b/c I'm going to replace the fuel pump this friday but I want to know if something might be wrong with my ECU or the wiring to the fuel pump, b/c people say 12 volts is required but others say lower voltage will work depending on the fuel pump. the more voltage the faster it spins, so for a crx what is the norm?

 

Do you mean yellow with a black stripe?
6V is not normal.
It should be 12.
Try testing again with the connector for the fuel pump (under your rear seat) unplugged.

This isn't even an ECU issue (yet).

 

i found a honda shop manual online and it says it should be between 5-8 volts on the fuel sender unit harness, so i guess I'm good with the 6.5 volts.

will give an update on friday or saturday after I replace the fuel pump...

 

UPDATE: it was the fuel pump. car runs like a champ now. but in the process somehow I broke the fuel guage lol. it just reads completely empty all the time. so gonna do some troubleshooting over the week to figure it out.

 

Check the fuses under your dash. I had one go out and my rpms, fuel gauge, temperature, turn signals, and reverse lights stopped working one by one.

 

Maybe the connector to the fuel sending unit is not fully seated. Was it disconnected when you replaced the fuel pump?

 

yes I disconnected the wire harness going to the fuel sending unit when we dropped the tank. we didnt fully drop the tank just about 8 inches or so, just enough to get the fuel pump out. which was probably a mistake. took alot of adjusting the tank while it was barely balancing on a jack. ended up spilling gas all over ourselves lol, funny now but wasnt at the time.

Im hoping for it to just be a fuse (fingers crossed) I hear there is a 10amp fuse that could go.

only problem, while trying to troubleshoot the fuel pump everyone told me to jump 12volts from the battery directly to the fuel sending unit for some reason. (unless they meant jump 12 volts to the wire harness that splits off to the fuel pump) so i disconnected the wire harness and ran speaker wire straight from battery to the 2 metal connectors directly attached to the fuel sending unit.

do you think I fried the fuel sending unit by putting 12 volts to it?? b/c normally i know it receives 5-8 volts.

 

You have to jump two pin outs on your main relay plug to get a 12 volt for the pump.. don't waste your time.. take fuel pump out.. hook it up to 12volt an put bottom half in a cup of water.. if it shoots the water like 12 feet in the air... pumps fine... if it comes out lightly an not shooting like wild in the air its the pump.. I can almost guarantee its your fuel pump.

 

Alrdy replaced the fuel pump. Car is running again. But in the process my fuel gauge no longer works
. Its getting around 6.5 volts like it should so I think I fried the fuel sending unit by putting 12 volts to it :/

 

Did you check whether the fuel sending unit connector is fully seated?

If the connector is fine, with the key in ON(II), ground the Yel/Wht wire at the fuel sending unit connector. Does the fuel gauge needle rise to full?