1996 2.4L Stalls, Dies, Starts, Stalls, Dies

Without starting fluid to restart I will have to let the truck sit at least 20-30 minutes.

If started with starting fluid it will pretty much die immediately.

Not only when it idles for 15-20. I have had it stall out while driving at least 6 times now. most of the time I was able to get it going again and make it to my destination. Twice I had to have it towed.

Plugs didn't look horrible last I checked. They were a bit dirty but no horrid corrosion or anything like that. All were still properly gapped as well. Replaced them about a year ago, but may do it again since they aren't expensive.

 

Fuel pump/EFI relay, maybe

 

Checked those per the FSM and they were fine. As well as the circuit opening relay.

This thing has had me stumped haha

 

Alright guys I have a strong feeling I have figured this one out but will report back if I am wrong or right.

As a brief refresher I had a P0171 code after my truck died on me and I loaded the parts cannon and went to town, and was a big disappointment. Fixed a few things but the truck kept stalling. Code went away and have no other codes.

spent $80 to have a shop hook it up to their computer to see if it was something electrical. It was not.

So today I decided to check the inside of the fuel tank and see how it looked inside. When I swapped the fuel pump it was about to start raining so I didn’t get a good look inside before sealing it back up. Well upon investigation there is a TON of rust and sediment in the bottom of my tank.

So here is my theory, truck starts and runs fine but as the pump is pumping, sediment is building up on the strainer. Finally enough sediment builds up to restrict flow enough to kill the engine. Once it sits for10-20 minutes, the sediment falls off and allows it to flow again until the cycle repeats.

I’m going to check the tank at the junk yard and see if it’s better looking inside since it’s only $22 but if it’s not I’ll be scrubbing out mine and will let y’all know if this fixes my problem

 

Have a 96 Land Cruiser and it did the same thing. Test the ignition ignitor. I believe it has one.

 

Will definitely check that next. But boy do I hope this is my issue. It has plagued me far too long haha

also, the shop that had it hooked to their computer said nothing electronic was showing anything wrong when they were diagnosing it. But I’ll read the FSM about that

 

If it works enough to not tell the ecu it won't throw a code , it needs to be be bench tested. Should be on the passenger side near or on the fender or fender well. Should be silver with blue or black label. Wide oval connector.

 

From your description and a google search I’m 95% sure I know exactly where it is.

I’ll yank it out tomorrow and give it a go! Thanks for the idea

 

Igniter was a problem on my old truck

 

If it ends up being that get Toyota. It lasted almost 25 years, they are well made.

 

Yea I’ve tried to get new or used OEM for everything. I have a 95 Land Cruiser and it’s done me well on OEM. The local pick and pull by me NEVER gets Tacoma’s and they finally did but I went 9 days after it was on the lot and this is what it looked like vs what I showed up to

 

I gotta say this theory has Merit

 

Back. To. The. Drawing. Board.

Finished cleaning out the tank and put a new gasket on the fuel pump assembly hat and fired the truck up. Things were great, feeling confident having a good time and I let it idle for about 45 minutes intermittently revving the engine and whatnot. No issues, none. Came back later just to try it again and had the same results. Everything was wonderful so I took it for a 30 minute drive and didn't have a single issue on the drive. Got some gas and made it home. Go out to drive it about 3 hours later and make it a half mile before it shut down at a stop sign on me and wouldn't start again. Had my wife crank the engine and I held my ear to the gas tank (haven't put the bed back on yet) and I don't think I could hear the pump running.

I am going to swap the computer again and see if that was it and test my EFI/fuel pump/ circuit opening relays again.

Also on the hunt for an OEM ignition ignitor as well.

 

A completely random problem

Years ago with my 87 4Runner my Big feet would bump the fuse block enough to knock the EFI fuse loose Have you checked all the fuses are tight in the fuse block.

At times I make the mistake of not double checking the simple things .

Any help close at hand sometimes extra eyes is all it takes.

Best of luck

 

I’ll be retesting all the fuses today so I’ll make sure they are snug when I put them back in.

I did test the fuel pump again last night and got some interesting results.

I connected the fuel pump directly to the battery and got nothing. No pumping or anything. Tried moving the leads and connecting again to no avail. Then I tried to crank it and it started right up, idled and died. Reconnected the leads and the pump was running just fine. Hooked it all back up and the truck ran and idled great. It was late and dark and didn’t feel like getting stranded somewhere else so I left it where it was and am going to go get it this morning.

I’m debating swapping the fuel pump again cause it seem to be deciding when it does and doesn’t wanna work.

unfortunately I am probably the most mechanically inclined of my local group of friends so they are all as puzzled as I am

 

There's a relay on the drivers side inside the cab and EFI relay in the engine bay.

 

Since the bed is off you went direct to the fuel pump connector when you applied battery voltage??

Nothing corroded on the plug . Your jumper was grounded to the battery or you used a frame ground ??

it should pump and you should be able to hear the returned fuel in the tank if not the pump running

Did you go with a Denso Fuel Pump .

I think I would measure voltage at the pump while cranking and running .

then when cranking right after it quits if you still have voltage it is between the connector and pump

 

Correct, I made some 12' leads and went straight from the battery to the fuel pump to terminals 4 and 5 from the FSM. I disconnected the return line from the fuel pressure regulator and put a can underneath it to catch the fuel but the first few tests it was not pumping at all. Tried battery and frame grounds. Then after trying to crank the engine it fired up then died. Hooked the leads back up in the same manner and it would pump.

I'm going to get some electrical contact spray and clean out the connections as well but you are probably right in the thought of something inside the fuel pump rather than the connections. I'll pull it out and try and test that.

Also, it was a Denso pump however it was one I got from a junk yard Camry that uses the same part number.

 

Well I think I have figured it out and will put SOLVED in the title if the truck continues to run well for the next week or 2.

Just a reminder this started with a P0171 code, fixed a few issues but the problem remained, truck would idle for about 20 minutes then shut down or would get me out on the road and die.

Well I bought a new Stant gas cap and so far so good. Let the truck idle for an hour the other day and rev'd the engine a lot, never had an issue.
Let it idle for 40 minutes then went on a 40 minute drive then let it idle for another 30 minutes and again, no issues.
Have been driving it for 2 days now with about 5 trips usually being about 20 minutes each, and no problems.

Only reason I tried it was because When I would loosen the gas cap there would be a LOUD and a lot of suction of air into the tank. I know there will be some but this just seemed excessive. I figured maybe the negative pressure being created in the tank from the pump was too much for the charcoal canister purge to handle on its own and the venting from the cap wasn't allowing an equalization of pressure, causing the pump to shut down. Similar to my rust in the tank theory but different.

Really not sure if this was the true fix since it has only been 2 days, but just goes to show ya start SUPER SIMPLE FIRST.

 

That is the thing these new fuel caps don`t vent !! All the fumes are vented out through the Charcoal filter

A leaking cap that vents will cause a Evap code to trip.

Going to be interesting