Hi All,

I have been a lurking on here for a while and have seen some great knowledge on here. Hate for my first post to be a question but I am stumped on this one and hoping someone can straighten me out.

I have an 85 with just under 50K on it. It was running fine a couple weeks ago but now I can't get it started. I can get it to start with some starting fluid. So it has spark and air so that lead me to fuel problem. I followed some advice from here and realize I think the pump went out on me. I have zero pressure. I buy a new pump install and hear and feel it turn on. car still won't start. Try a new filter blow air through the line that is not it. I take the pump out submerge it in a bucket of fuel and turn on. Pump doesn't pump. I figure ok I got a bad one off the shelf. bring it back get a new one, install and still will not start. I didn't check pressure again because I don't have a pressure gauge handy. I am assuming it still is not getting pressure. Can someone tell me what am I missing? Is there a priming procedure or something? Could it be the
pulsator possibly? Any advice on where to go would be appreciated greatly because I am confused on this one. Seemed pretty straight forward going in but it has been a head scratcher.

 

Without checking fuel pressure with your second new pump in, we'd just be guessing. You can borrow a gauge from Autozone for free.

As for the pulsator, just replace with a piece of fuel injection hose and clamp securely.

 

Yeah,

I can get one tomorrow on way home. Just find it hard to believe that I would have 2 in a row out of the box not work? Seems very unlikely.

Thanks Frizle. Was kind of hoping I would catch you. read another thread where you walked someone through with zero knowledge on testing and multiple meter usage and you were great with your responses and knowledge on the subject. I will get a gauge tomorrow and see what it is reading. I am pretty confident it will be zero or close to it.

Let me know if you have any random thoughts to check. Not my daily driver so I am in no hurry to get it fixed just really frustrated by what I thought was a simple problem and fix.

 

When you had the 2nd pump in the fuel did you hear it activate? Were the connections tight? If it didn't activate, did you check the FP fuse?

You changed the filter....it should have an arrow on the outside showing the flow direction...installed correctly?

 

What John said. Assuming your new pump is running, the pulsator replaced with F.I. hose, the filter is new and oriented correctly, and you've ruled out obstructions in the pressure line, you should have 38-45 psi of fuel pressure at 2 second key on prime. It should hold pressure for several minutes.

If all of the above is correct but you have no (or little) pressure, run 12V to terminal G on the ALDL. Check again for pressure reading. Now pinch off the return line and see what happens. Suddenly get full pressure? Replace fuel pressure regulator.

Post what your results are when you pick up the gauge. This should be an easy fix.

 

John,

Yes 2nd pump activates for the 2seconds it should. Had the wife turn the ignition on while i had my hand on the top of the fuel filler. felt and heard it turn on. It is still in the car.
Fuel filter is right direction. It says out (no arrow) and that side is closet to engine as it should be. connections are good, fuse is fine and I am stumped.
I have a pretty good mechanical aptitude. I have rebuilt engines swapped transmissions etc. I am not a pro but not a complete noob either. This is just flat out weird. By all rights I should have pressure and it should start. And as I said before it will fire if I squirt fluid in the intake and it runs for a couple of seconds while the fluid lasts.
I am gonna go look at the pump instructions again. Maybe I missed something there? It seemed pretty basic but maybe there was a cover or something on the pump intake that should have been removed. But I have changed a couple of electric pumps before and never saw an intake cover for instance. I Did see a filter screen on the intake Of this one but that was all.

 

Did you re-install the pulsator or replace it with a section of hose?

I had experienced a problem a while back where the pressure from the pump forced the pulsator off the fuel feed tube leading out of the tank. The pump would run, but the fuel was flowing back into the tank. Try replacing the pulsator with tube and two screw clamps if you still have the pulsator in place.

 

I just pulled the pump back out of the tank. I looked at the original pump and it didn't have a filter screen over the intake like the new one. So I removed the screen thinking maybe it was restricting flow. The pulsator was still in place. I haven't replaced it with FI hose yet. I have the hose but don't have any clamps handy. So I will replace the pulsator tomorrow too.

I put it back in and tested to see if it would start. No luck with the screen removed either. So that will go back in also.

I then went and checked to see if I would get any fuel pressure squirt out at the rail if I pressed in the schrader valve on the rail. I got not a drop so I would say that there is zero pressure even without a gauge to measure it. Would you agree with that?

I will confirm with the gauge but this is one of those dumb things that will drive me crazy until I figure it out. Thanks for the help so far. Hopefully with this groups help I can get to the bottom of this one. I just got the car back from being stored at my house in CT and I would love to drive her. It's been a long time and now I can't get her to run.

I am Still stumped?

 

The pump you bought was plug n play, right? No chance you reversed the polarity on it? I've gotten both from the discount houses....some were complete with the plug, others I had to crimp it on.

It sounds like the pulsator has split. Do the F.I. hose section first. Don't run the pump without the filter sock in place....in fact, the stores usually won't honor the warranty on a new fuel pump unless you can prove you bought the sock too.

No worries....there really isn't much to the fuel system. We'll get to the bottom of it.

 

Frizle,

That is my next step I think. It was not plug n play. I had to replace the ground and power wires. I did install them back to the corresponding sides where the original pump was wired. You think they are reversed on the new pump. Would that power the pump but not make it pump? The new pump uses a small pin connector type. The power wire was just a complete swap out. The ground I had to cut and splice because the ground was soldered to the tube. I soldered the splice together and used fuel resistant shrink tube over it. There was no indication in the wiring instruction that the power and ground pins were reverse from original.
I inspected the pulsator for splits/cracks etc. Didn't see any.

Also I had the sock on the whole time. I did buy new one with the pump. That is why i had no trouble swapping for a new one. there is a small wire mesh secondary filter screen over the intake of the pump. That is what I removed.

 

I've never seen a pump with the postive and negative reversed from original, so if you wired it the same as it came off, you should be fine. Now,.....on the pulsator, I know you inspected it for tears, but is it clamped securely? The fuel flow could be escaping from where the pulsator clamps to the pump or the fuel tube.

 

OK

Here is the result. I came home replaced the pulsator with FI hose and clamps. checked wires and seemed correct to original. Dropped in the tank made all connections. Turned ignition on and of a few times to pressurize the system. Tried starting. After a couple of cranks it started.

So I guess it was the stupid pulsator. It didn't have any clamps. it is more like a pressure fit o-ring on each end. guess the pressure fit was not allowing a good seal and not creating vacuum for the pump?


Now my next problem is it is running rough and throwing a code. It didn't do this before the pump issue. I will have to either get it scanned or I think I can jump the ALDL and count flashes on this OBD1 system to retrieve a code if I remember correctly. It has been a long time since i have had a check engine on this car. But that will be tomorrow or later this week/weekend. If you guys got any thoughts on that I am all ears.


Thanks for the help on this problem. I appreciate it.

 

The pulsator has caused many a heartache....glad you found that problem. I would still test fuel pressure to ensure it's up to snuff and not causing / aggravating the new rough running issue.

The 85 OBD1 system is very simple. Jump terminals A and B on the ALDL, turn key on but don't start. You should get 3 "12" codes (flash pause flash flash), then any stored fail codes, then 3 "12" codes again.

That should tell us where to look.

 

I will definitely test the pressure. Will have to be tomorrow or Friday. Too busy with work today. I think it may be a pressure issue that is causing the rough running. It feels and sounds like a pulsing type of rough.IDK?

I also found the code reader for this car along with the code key book it came with. Forgot I had it. Bought it 20 years ago for this car and may have used it once. So I won't have to jump the ALDL. Amazing what you can find in the back corners of a tool chest when you really look.

It didn't throw a code back out last night. I disconnect the battery when not using because of the typical hatch ajar switch that I need to deal with too. I am just starting to systematically go through the car and get all the typical bugs worked out. The pump was step one so I can move it back into the garage since I completed the wife's trans swap on her GTP a couple weeks ago. I will update again when I can get an accurate pressure and or a code to work with again. Thanks Frizle and John.

 

Just tested the fuel pressure.
After relieving the pressure and checking with just the key on I was at 15 psi. With the car running it was at about 37psi. It is currently holding pressure with car off after running at 32psi. Down from 37 but it has been about an hour of sitting without pump being run. What is normal for leak down of pressure?
Car also isn't throwing a code after I reconnected the battery and left battery connected so I didn't clear it out. I will take for a good ride tonight and see if I can get a code to come back on. It isn't running as rough as it was but it definitely is 100% throttle response.
Any other ideas of where to start looking would be appreciated.