stalls after 30 minutes, will not restart till cools off

[surewood]

I have a 1984 2.4 720.

I've been reading all the posts here for days, and the problem still happens.

I replaced the fuel pump relay 2 times thinking I got a bad part. I also soldered the original as I read on here.

I replaced the fuel pump and the filter 2 times.

I did a tuneup as well. 

 

I'll drive for 20 to 30 minutes, then the truck stalls while cruising down the road. Usually it will restart, but if I give it any gas it stalls.

It seems like it is not getting enough gas causing it to stall. I can turn the key to hear the fuel pump, so I know the fuel pump is working.

It was also dieseling when I turned the truck off before this problem began, may not be related.

 

The good news is that I can finally create the problem by having my truck run in the driveway for 30 minutes till it stalls and will not restart.

Re-creating the issue is way better than calling my mechanic while dead on the side of the road. 

 The engine just turns and turns but does not fully start up till the truck cools off, either 30 more minutes or many hours later.

Sometimes it will start, but if I give it any gas, it stalls.

 

 

Any advice on other parts and money to throw at this little monster?

 

[Stoffregen Motorsports]

Based on the limited info here, it sounds to me like a bad accelerator pump or just plain dirty carb.

 

Did you do any work to the truck before this started happening?

[Rhino13]

Have you checked things out/tried starting it with the air cleaner off? Mine was doing this with the stock carb and it was some little vacuum actuator for the choke that had broken and would cause it to close and choke itself, then turn off and wouldn't restart until what I assumed to be the choke coil cooling down and letting it reopen.

[surewood]

I had my mechanic instal a new speedometer cable put in before this started.

Everything runs great right up till it dies.

 

What information should I try to round up to get a better opinion?

 

I'll look into seeing what the choke is doing with the air cleaner off.

[flatcat19]

Think fuel; fix ignition.

 

How are plugs, caps, rotors, coils? Timing set?

[surewood]

After I thought the problem was fixed with the new Fuel Pump Relay, I put in new plugs, cables, distributer, and rotor. It's been running nice and smooth.

I did not replace the coils. 

 

I have been reading about Ignition Control Module heating up and causing a similar issue.

Autozone has the Duralast listed for $250 or Proform for $22.

That is quite a difference.

[bmxninja357]

This is what I did

 

https://axleaddict.com/auto-repair/The-Datsun-and-Nissan-Pickup-Fuel-Pump-Relay-What-the-Haynes-Automotive-Repair-Manual-Wont-Tell-You#

 

Even our piss poor soldering job has worked for about 10000km so far with no trouble. It's easy and virtually free and I bet it works.

 

Peace

Ninj

[datzenmike]

The chances of both coils failing at the same time from over heating is vanishingly small.
 
Module? Cheaper to check for spark first than throwing parts at it. Next time it won't restart, pull the coil wires off and put an old spark plug in the ends. Lay on a grounded surface and crank the engine over... GOT SPARK?????
 
YES... go to FUEL
 
NO. Get a can of refrigerant for computers. Spray the distributor to cool it down. Does spark come back? Might be the module.
 
 
 
 
 

Sometimes it will start, but if I give it any gas, it stalls.

I'll drive for 20 to 30 minutes, then the truck stalls while cruising down the road.Usually it will restart, but if I give it any gas it stalls......

Next time the truck is warmed up, after about 10 minutes, take the top off the air filter and look. Is the choke plate fully vertical and open? or is it partly closed?

[surewood]

It took about 45 minutes to finally sputter out in my driveway today.

The choke plate seemed partially closed while running.

I have spark from the coils.

I don't see any gas going in while I try to start it.

 

EDIT: the choke plate is fully open after 10 minutes

[surewood]

I just checked the fuel pump again while it wouldn't start up.

I took the hose off the out line of the pump and had my wife turn the key.

 

It started right up and the pump was pumping out gas properly.

It wouldn't start before, unhooking the gas line seemed to make it start up and run off the remaining gas in the line. 

[banzai510(hainz)]

when it dies. pull the aircleaner off and then cycle the gas and see if the accell pump is squirting gas in the main barrel of carb. IF NOT then the carb is running out of gas which could be a sticky needle valve. Or fuel pump is not pumping after certain mount of time.(just guessing now)

 

 

vacuum lock? Be honest I never had this happen and just tell other people if a hot day. Take the cap off fuel tank?

[surewood]

The truck just died again down the road to work, which is only a couple miles.

I didn't hear the fuel pump making noise.

I made a jumper for the fuel pump relay and the fuel pump started working again.

This is the 2nd fuel pump relay I've tried.

Do I keep buying the wrong part?

Or another bad relay?

It's the duralast relay from autozone, part #20550 

[banzai510(hainz)]

you cant test the relay. Put 12volts on the coil part and then ck the ohms on the circuit open/closed part. should be shorted.

 

Datzenmike is the fuel pump guy on the later trucks. Maybe it comes on when it only needs to?

[surewood]

While the truck will not start this time, I took off the out line from the fuel pump.

There is no gas pumping out.

It's making sound like it's working, but nothing comes out.

 

I'm beginning to think I have junk in my fuel tank that gets clogged up after running a while.

Tomorrow I will hopefully get the fuel tank off and checked out. 

 

I think every time I have checked this, releasing the pressure or with enough time, the clog goes away and it works.

[banzai510(hainz)]

I heard of half tank things start going bad as junk plugs up line. Never seen this myself but heard of it on here.

 

when FULL it does it less?

[surewood]

Can't say for sure. It did it with a 3/4 full tank last week. 

It seems to crap out every time from driving for 20 minutes or parked running for 40 minutes.

 

I would go fill the tank right now to see, but have plans to take the tank off at the shop tomorrow and examine it.

[Doctor510]

???Fuel filter(s)???

[surewood]

fuel filter is fine. no clogs. Just put a new one on the other day. The old one had some rust sediment in the bottom, but wasn't real bad and flowed when I blew on it. 

 

My mechanic seems to think the screen or filter in the tank is building up junk till it clogs up but then the junk falls off while the truck is "cooling down".

[datzenmike]

The relay only follows how it was designed. There is an input from the oil pressure sender, the alternator, (charging) 12 volts from the fuse box, starter signal and a ground. My FSM does not describe the operation exactly but I assume that key on starts a timer to prime the pump. It keeps pumping as long as the starter is ON. After start up oil pressure and a charging alternator are needed to keep the pump going. Not sure though, but why else have those inputs?

 

If you jumper the relay and force it to run continuous... does this fix the problem?

 

Yes... the fuel pump relay or the inputs are the cause

No..... there is something wrong with something other than the fuel pump. Plugged line, carb...??

[surewood]

Took the tank off and discovered about 2 cups of junk.

After I cleaned it all out and fired it up, it died again.

I checked the fuel pump, and it seemed to be working at half power.

It was just spurting out fuel at half the usual rate. 

Replaced the fuel pump, and so far so good.

 

I've been all over the city today and drove for 2 hours with no problems.

 

So I think it was the junk in the tank this entire time. It would run for 30 minutes, suck up the junk and stall, then after a while all the junk would fall out and I could start it again. This strain is what made the fuel pump start to crap out. At least that is what I'm hoping. 

[surewood]

After yet another fuel filter crapped out, I read on a few posts here that the pumps at O'reilly Auto Parts are no good.

So, I came across a Facet PRO60SV 32 GAL PER HOUR 3.5 PSI.

I hooked it up, and everything felt and sounded great.

The next day, it dieseled when I shut it off after driving 5 miles, then began idling poorly at my next trip.

I got home and discovered a gas leak out of the carburetor accelerator pump.

The boot on it was cracked and gas was squirting out.

 

I see accelerator pumps in stock at Autozone, but was wondering if they will do the job.

Well, mainly, I'm wondering if this pump is too strong and responsible for this leak and future leaks.

 

Fun times. 

[Rhino13]

If its rated at 3.5 then you're fine. Keep with the facet, they are in my opinion the best pump for the money. Charlie69 recommended them to me and I haven't touched it since. I would try the replacement from autozone, but I'd also suggest just giving the whole thing a rebuild kit since its cheap and will prevent any other problems in the carb.

[datzenmike]

After yet another fuel filter crapped out, I read on a few posts here that the pumps at O'reilly Auto Parts are no good.

So, I came across a Facet PRO60SV 32 GAL PER HOUR 3.5 PSI.

I hooked it up, and everything felt and sounded great.

The next day, it dieseled when I shut it off after driving 5 miles, then began idling poorly at my next trip.

I got home and discovered a gas leak out of the carburetor accelerator pump.

The boot on it was cracked and gas was squirting out.

 

I see accelerator pumps in stock at Autozone, but was wondering if they will do the job.

Well, mainly, I'm wondering if this pump is too strong and responsible for this leak and future leaks.

 

Fun times. 

 

 

This is a sign the carb is flooding (possibly pump pressure is too high). The carb is over filling. Look at the round glass on the front of the carb. Fuel level should be half way up on the glass.

 

Flooding will cause run on or dieseling.

Flooding will also leak out the accelerator pump if the boot is split

Flooding will cause over rich and poor idle.

[surewood]

It seemed like the carb was flooding. I'll confirm in the morning.

If it is the new pump causing this, what is the ideal pump to get?

[Cheetahking]

The pump can't really be responsible for overfilling the carb - unless its at too high of a pressure.  

More likely the needle valve that is supposed to stop flow into the bowl when the float rises, is not working or getting junk in it.