Hey all looking for some help. I have a 94 Del Sol Si D16z6 lately i can't drive it since RPMs will drop and cut off coming to a stop. trying to turn it on right after this happens i can't hear the fuel pump prime but after a few mins it goes back to normal. Last night this happened again and i got a fuel pressure reading of almost 0. Sometimes at a cold start i can't hear it prime either. Tapping on the main relay appears to make it prime. Am i looking at a failing fuel pump or a bad relay? I just finished checking the relay for continuity and had cont. throughout. i've also checked the filter, injectors, strainer(filter at the pump), and checked for blockage. Any suggestions would be very much appreciated

 

Try the regulator

 

replace or fix (re-solder) the main relay.

 

Yup doing that now. I had all the stuff to do it so i figured it wouldn't hurt to try. As for the regulator i tried three different ones and it didn't affect it.

Should the re-solder not yield desired results, would it be safe to say its the fuel pump?

 

Seeing that you can read fuel pressure, one fuel pump test is to pinch off the return line for 3-5 seconds and your fuel pressure should double. Don't pinch longer than 5 seconds though. Doesn't rule out the fuel pump 100% but it's a quick and easy test.

 

+1 on checking into relay or swapping with known good one.

 

Should it not work, do what coooljmp suggested. It will most likely work.

Lightly tapping on the relay is an excellent way to confirm a faulty relay, it's the street-smart way of troubleshooting a bad relay. First you check for voltage (in your case, you can hear the fuel pump) then you confirm the bad relay by tapping it. You'll never read that in a manual, but it has always been my second step, even on $1,000,000+ equipment. Works on pneumatic valves and probably hydraulic valves too.

On one of my cars, I've seen the connection to the top of the tanks sender corrode. I live in an area where they use a lot of road salt.

 

Should it not work, do what coooljmp suggested. It will most likely work.

Lightly tapping on the relay is an excellent way to confirm a faulty relay, it's the street-smart way of troubleshooting a bad relay. First you check for voltage (in your case, you can hear the fuel pump) then you confirm the bad relay by tapping it. You'll never read that in a manual, but it has always been my second step, even on $1,000,000+ equipment. Works on pneumatic valves and probably hydraulic valves too.

On one of my cars, I've seen the connection to the top of the tanks sender corrode. I live in an area where they use a lot of road salt.

 

Thanks all who chimed in i really do appreciate it.

I re-soldered the relay last night and let it sit over night. I havent gotten a chance to try it out yet but when i get home I'll test for continuity and try it then if not I'll try a few different relays.

Also, the fuel pump doesnt always prime. Most of the time it will bit occasionally it wont and at that point tapping on the relay would make it kick in halfway through the priming cycle.

stupid question: with the re-soldering is there a chance the relay could still be bad?

Thanks a lot again and ill post an update a little later

 

Yes. Besides some damaged soldering points (over time), honda relays are very reliable.

If it's a soldering issue you should be able to see where the defect is. Sometimes it's hard to see. Here's an example of what to look for:

 

sounds like your pump is dying, fuel pumps get dead spots on them. so if your pump lands on a dead spot sometimes will be hard to start or youll start losing fuel pressure all together.

 

Swap out the ECU with a known working one.

Old del sol's ECU's fail and act like a bad fuel pump.

 

First off, I want to give a HUGE thanks to everyone who's chimed in. I really REALLY appreciate the help.

Now for an update: I've been driving the car sporadically to run small errands and what not in light traffic and it hasn't tried to cut off. The real test is tomorrow when i drive to work 40 mi round trip in morning/afternoon traffic.

So what I did: I re soldered all the joints on the main relay. Now, I'm hearing the pump prime every time and the joints looked like the ones in the picture 2point2 posted and the ones that didn't look like that were well on their way there.

One last thing I need some reassuring on: Before I can mark this case closed, I wanted to post a pic of my fuel pressure gauge marking the fuel pressure I have. I think the pressure is still low but could use a second opinion. I'll post a pic tonight when i get home.

 

Alright so here is my fuel pressure on idle. is does it look normal?

 

pretty sure 45 psi is spec for b series but you might be ok. I think vtec fuel pumps have higher pressure too. plus your cars older so Id say your safe but Id google it

 

I have a D series pump so yeah I would think it would be lower. I saw a diagram (for 92-95 Civic/Del Sol) saying with the FPR hose unplugged I should get a reading of 40-47 psi and 31-38 psi plugged in. I've checked over and over and even in the pic I posted it's always at 32 psi and 42 psi with the FPR hose unplugged.

I did take the car to work today and it turned off once but started back up when I pressed the clutch. Other than that no trouble.

I did clean the IACV and bled the cooling system and also adjusted the idling screw on the side of throttle body and taking it out for a test drive it felt a bit more normal.