Fuel pump constantly cycles?

Hi,

If the pump won't stay running, but the spark plugs are wet, chances are you lost ignition spark to the plugs. The system is designed to shut the fuel pump off if there is no ignition.

Do me a favor. Check to see if there is spark to the plugs.

Here is a link that explains how to do it:

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

Let me know what you find.

Take care,

joe

I checked 4 of the six, 2 on each side and they all had spark. The pump will run if i bypass the relay and I can only assume it does when it’s running, however it hasn’t yet, lol. This repair has been going on a couple weeks now, started as shutting off while driving, fuel pump would not work when I got it home, put in new pump and it wasn’t getting signal to prime with key on, that’s when I learned how to bypass the relay. It ran perfectly for about 45 seconds then would bog down and shut off. I'm sorry for only getting you a part of the info to start, I had been working with another mechanic here (Steve W) and hadn’t heard back from him in a few days, I hope the guy is ok, he’s been a big help. Anyway, it seems I’m chasing a ghost or a ground problem because symptoms and codes lead me to changing TPS, crank sensor, ICM, plugs and wires and cap and rotor are new, fuel pump obviously and filter, positive side of my battery cables. after putting those in my fuel relay started getting signal however it’s getting to many lol. Pre battery cable I was able to get it to run for the 45 seconds like I was saying (about ten times in a row) but after cables I am not getting it to run, although my pump is priming, lol. It's gotten well past frustrating. I’ve checked and cleaned a handful of grounds, I even ran a couple cables in tandem on the negative side to see if I needed to change that side, but it hasn’t made a difference. The only two grounds I haven’t been able to get to and probably are important are on the topside but behind the back of the cylinder head, there is so little room, but I guess that’s where I start again tomorrow.
Thank you for your help and input.

Oh yea, I replaced the ignition wire harness today and first crank it almost sounded like it wanted to go but it did not.

Last two codes I had were 1361(ic system low voltage) and 0122(throttle position sensor) which has been there since day one after clearing and introducing new codes and clearing them, it must be a wire I haven’t found yet.

Lastly, I used this method to come to the conclusion there is some kind of almost short in the ignition system because removing fuse 9 almost makes the test light go out, it goes very dim.
https://youtu.be/9wLrTjeb9TY

A little progress today, didn’t realize there were two different grounds at the radiator support and the one I didn’t already clean was the core ground support or something like that, the third negative coming off the battery, cleaned it & the mounting surface, now my fuel pump keeps cycling through the priming process only sometimes. So, I’m happy for a little progress, I'm going to try running a second core ground in parallel to it, just to check and keep looking for and finding grounds. Thanks again for the help.

Hi,

I have to go back to the spark plugs. You indicated they are soaked. If you have an ignition spark at the plugs, it should start unless there is a compression issue or timing issue. You should at least hear it fire on and off or backfire.

Is it possible for you to record the engine cranking and upload it for me to hear?

Let me know.

Joe

I will do that tomorrow, Thank you for all your efforts and willingness to help me solve this crazy issue.
I know I threw a bunch of info at y’all and I I can’t thank you enough for jumping in, without even seeing a vehicle and offer excellent advice for those of us that aren’t afraid to give it hell however absolutely need some direction lol. I’ve done the majority of work on my own vehicles and the amount I’ve done grew with experience. I don’t mind getting dirty and enjoy learning, but electricity is by far my weakest skill set.
So, after installing the new ignition switch wiring yesterday, the first crank gave an indication that it wanted to fire but fell short. Today, after finding and cleaning the ground wire I had missed previously that came off battery negative, first crank did backfire, not huge but definitely backfired, no further progress though on the next few attempts.
This vehicle died while driving when this problem started under no crazy conditions, early morning, 6 miles into a 10-mile ride, no rain or anything that I could imagine would contribute to it. It’s bizarre man, did I mention that when I first put the new pump in, I could get it to run for about 45 seconds before it would bog down to stall, while running I could press the gas pedal and it would rev accordingly, when it wanted to stall, the pedal was no help. I was able to get it to run only by bypassing the fuel pump relay as it wasn’t getting any priming signal. Since replacing the positive side of the battery cables, pump is receiving priming signal, however now it won’t fire up.
Thank you for your time and I seriously mean that.

Hi,

If it backfired, you may have fuel filled spark plugs. Have you removed and inspected them? That can cause a backfire.

Take a look at this link:

https://www.2carpros.com/articles/engine-backfires-while-running

Let me know. Also, let me know if you have rechecked the fuel pressure to make sure the regulator isn't acting up. Make sure the vacuum hose to the regulator isn't wet with fuel and it is attached to the intake. I believe it is under the front of the intake on this engine.

Let me know.

Joe

I will do it Joe. Didn’t get a chance to do anything with it today, because the rain shut me down. I’ll look into those things and have some video as well. Thanks again

Sounds like a plan. If you have a chance, send some of the rain to Western PA. We need it. My yard looks like I live in the driest part of AZ.

Take care and I'll watch for your reply.

Joe

Man, it was storming last night, had an F1 tornado roll through about ten blocks from the house, crazy weather.
So I was able to do a little checking, after finding, cleaning and re-attaching the core support ground( I even ran an extra one in case it needed some extra love), the shorting or I guess you call it an open ground circuit, that was observed by pulling positive post off battery and connecting 12v test light to the post and other end to the terminal, the only fuse that had any change was #9, IGN/BATT, and it would get very dim but not go completely out. We went away after redoing the core support ground. The only DTC code at the time was TPS sensor, which has been there since this problem started, even though I’ve put two different new ones in. Gave it a crank and ut basically just cranked. I can smell fuel, pulled three plugs from passenger side (2-4-6) and they were wet with gas. Now it gets interesting, # 4 plug was didn’t show me any spark, #2&6 did then come to find out the plug in 4 was cracked, ok I’ll accept that I probably over tightened it. I have some videos I’ll send also. While getting the video I noticed the plug in the #6 spot is arching through the plug boot I guess to the block, got a little footage of that and that kind of freaked me out because I never saw it before and plugs, wires, cap and rotor are new. Looking it up I guess it could happen because it’s a little wet there from the little bit of gas, but I don’t know. DTC code p1335 was added to TPS sensor and p1335 says crank position sensor however the guy I was working with here before you said that meant low voltage to ignition system & has me do voltage test for crank, ICM and coil, I’ll send those results as well as I haven’t heard back from him in a while and that’s totally fine, I appreciate any and all help !!! Then the storm came and shut me down again. So, to summarize, had fuel and spark (in 2 of the three cylinders checked anyway) but no ignition. I’m just getting going down here today (in Florida) and I’ll send the video and results from test done previously and anything else I can find to you shortly ok. Thanks B again man I can’t tell you how much I appreciate you input.

When I noticed the arching, I had a different set of plugs in than the new ones as they had all been pulled, this is the plug that had the arching, and I didn’t even notice it has a little bit of a crack in the ceramic.

Cylinder #2 after I pulled it and pouring the gas out

#4

#6

The plugs.

Spark test #2.

Spark test # 4, no spark, cracked plug

Spark test #6 you can see the spark go to the frame because it’s too close, sorry about that.

This is where you can see the arching in #6 with that Autolite plug in.

This you can see the little bit of gas coming out plug hole, I think that’s 4 cylinder.

I think that’s all of the decent videos I got, let me know what you think and I’ll try and send some rain y’all’s way !!!

Still waiting for the rain. LOL If you have that much fuel in the cylinder, either we have a leaking injector, a faulty regulator, or no spark. I watched the videos and am I correct in assuming the cylinder with the fuel leaking out had no spark? Was that the only cylinder like that?

Let me know.

Joe

The cylinder with no spark had the same amount of fuel as all the others. I guess I’m just realizing that I don’t know how much fuel would normally be in there because I’ve never pulled a plug and had fuel come out of them. If I shorted the videos to much or they didn’t have enough info just let me know and I’ll adjust, there is sound in all of those if you wanted to hear it cranking, one has the battery weakening but the others aren’t like that. They all have just about enough fuel to pour out of the plug after you take it out, or maybe it’s just that’s all it will hold, lol, sorry for the most part I usually am figuring some things out as I am saying or typing them, however no fuel pours out after removing a plug, that cylinder that didn’t spark(#4) did have the cracked ceramic on the plug and I'm hoping that’s why it didn’t show signs of firing. I didn’t retest the other side for the video. However, previous test showed all cylinders having what appears to be the same amount of fuel being injected. I'm guessing that would be more of a regulator problem, also wondering if said regulator would be cause for it to shut down while driving ? In reality it could have been a combination of things because I did have some ground wires that were concerning once I looked at them. I’ve never done the fuel regulator or injectors; any advice is surely appreciated. With that fuel being in the cylinders, do i need to do anything to clear it or will it evaporate with the plugs removed being good enough?
Oh yea, what do you think about the arcing in that one cylinder (#6)?

Thanks again Joe.

* no fuel pours out of the cylinder after plug removal, however there is just enough in the plug to pour out.

Is there anything related to installing the new fuel pump that could be influencing the regulator to act this way, I’ve done the pumps before and I’m just wondering before I do all that digging. This whole time it seems I’ve been chasing a problem that reappears down the line after renewing something, i.e., fuel pump became an issue with the fuel pump relay(had proper ignition at this time), replacing positive side battery cables gave me back relay priming but lost the ability to start and run which made me check spark related things. First, I replaced the pigtail on crank sensor for exposed wires then the crank sensor, ignition control module however not the coil because it tested good. Except for the fuel pump itself, everything I replaced gave me the same results as the part taken out so I’m sticking with the parts originally in it, so I don’t mess up anything new and I don’t see the need. Mind you I did the crank and igm before actually testing for spark because it only seemed logical, I can’t help but wonder if it’s something like the computer causing these different issues that actually aren’t issues, am I overthinking or is it the rise of the machines happening in real time, lol , no seriously lol. I’d like to think I’m not an idiot, but this issue has been wearing on me and as my mind normally goes, if I don’t know what it is, my mind starts at the worst possible situation and it goes south from there. Anyway, thanks for your time, sometimes it helps to get these things out of my head and it definitely helps when I do that to someone who knows better.

Not sure if I answered your question correctly, the cylinder that showed the little bit of fuel leaking down was the cylinder that didn’t fire, yes.

Okay, if the cylinder isn't firing and doesn't have spark but the others do, that takes me to the distributor. Is the cap in good condition? If you place your spark tester right at the cap, do you get spark for that cylinder?

Let me know. BTW, it finally started to rain here about an hour ago. Thanks!

Joe

It feels good to know I helped someone else, lol, especially when I need so much lately.
So cap and rotor are new, hadn’t put the tester right on the cap but I had spark on the one that didn’t fire when I tested it a week or so ago, just not the other day when I videoed it, as far as I know, I do most of this by myself and sometimes those a little hard to check, I can rig a separate starter switch but didn’t think I’d be going down this road. I’ll definitely try it right from the distributor cap, I can set the plug or test light so I can see it through the open hood.

Sounds like a plan. Let me know the results. I'm interested in knowing what you find. By the way, it's still raining. Wow, do we need it!!!!

Take care,

Joe

I’m trying to get myself in gear this morning, but the shrimp were running pretty good down here last night and I’m moving kind of slow, lol. Wound up with about half a five-gallon bucket though so I’m happy with that, even if my morning doesn’t start until about 12:30 today lol. Glad to hear y’all are getting some good rain, maybe the tide is turning for both of us!!!
Have a good morning, I’ll get back with you soon as I can.

Finally got to test them and all 6 plugs have good spark, via testing with an inline spark tester. Also, I pulled one plug from each side, and they didn’t seem to be getting as much fuel in them, after pulling, I got a little bit out of each plug when I turned it over into my hand, just a little came out. It seems like a more appropriate amount. She cranks fine but doesn’t act like it wants to fire at all, like I’m missing something from the equation. Where should I look next?

Hi,

If you have spark and fuel, it should run unless there is a compression issue or timing issue. Do me a favor. Remove the fuse for the fuel pump and see if it starts for a second or two.

Let me know.

Joe

That’s funny, I was going to ask you about something like this, what would this test be for?

With timing not adjustable here, how would the timing be off? Timing is another thing I’ve not done before, trying to put as much good info in my head as possible. Thanks man.

I gave that a shot, I wouldn’t say it sounded like it was going to fire but it did have a little more rumble to it as I cranked it.

Hi,

The idea of removing the fuel pump fuse was to prevent flooding if there was a pressure or stuck injector issue.

As far as the timing, the distributor may have been moved, the cap could be positioned is the wrong location, spark plug wires could be mixed up, and the timing chain may have jumped or stretched.

If it is possible, record it cranking and upload it for me to hear. I may recognize something that may help.

Let me know.

Joe

I sure will Joe. When I did the last spark checks I recorded all of them but they are very short. I can do a longer crank tomorrow, I’ll send either the longest or a couple tonight. I do have an issue with my distributor cap, the front mounting screw has stripped a bit so it wasn’t snugging down enough without slipping so I added pipe tape and it seems snug enough, considering it isn’t starting i snugged it enough to be comfortable doing crank tests but might have to sure it up when I get it running, i realize the cap & distributor itself are two different things, just trying to add all the info I can. In doing the last test I removed the fuel pump relay, I’m assuming that is sufficient for that test ? Thanks for walking through this process, I’m very grateful for your knowledge and insight