Stranded.. Engine starts up then dies (1 Viewer)

[SmokingRocks]

I was starting to think that myself actually ^

I'm going to get her on the lift so I can take all the plugs out and blow them out with compressed air. Then I'll let them all sit exposed for a day or so in the shop... Maybe that will do it..

I had noticed that the PO used a bunch of dielectric on all the connectors, however since I have gotten it I have cleaned the engine and rubbed off some of that grease. It seems as though someone has troubleshot this problem extensively once before.

The only other issue I've had with this truck was after running it through a deep stream crossing. Water got into one of the connectors (I think it was the main one for the TPS and stuff) the engine went into limp mode and wouldn't rev past 2k rpm or something like that. I pulled off the trail popped the hood blew out the connectors with compressed air and it was fine after that.

 

[Pin_Head]

Check the exhaust flow when it won't run. I have seen a couple where a baffle breaks off in the muffler and bangs around in there and sometimes gets stuck covering the outlet. After the enging dies, the baffle falls down and it runs good again until it plugs the outlet again. Sometimes it makes a whistling or blowing noise, but sometimes not.

 

[SmokingRocks]

What is the part number for the fuel pump resistor?

 

[blkprj80]

2308066030 FUEL PUMP RESISTER [sic]

 

[REDDAWNISHERE]

The last time I had a problem with the engine dying like that on my 80 it was the air intake. Check that your air intake tube is sealed from the air filter all the way to the manifold. If there is a crack in it or one of the hose clamps is loose that could cause it to die. I found a crack in mine, duct taped it closed and the lc ran fine until my replacement part came in the mail.

 

[zukinut]

I have a similar post on here from a few years back, it may help.

Try the IAC test it repeatedly with jumpers. After like 20 tests mine would get confused and go out instead of in. Fixed the problem for a long time.

 

[SmokingRocks]

If it was IAC though I should be able to keep the engine running by giving it throttle right? I do have a break in the intake tube line and I have duct tape on it now. It had been running fine with it duct taped prior to this, that was one of my first suspect items so I reinsured that it was sealed and I have a new tube on the way.

 

[ChiTown]

It sounds like your mass air flow sensor went south. Have you tried starting it with the sensor unplugged?

 

[westafari]

My MAF went south last week and the result was lots of black smoke and poor idle. I've also had various other idle issues. I also had a failed park/neutral switch which I've known about for a long time and had ordered the part from CDan already. As it turns out the park/neutral switch also provides feedback to the EFI and ECM so once that was installed not only did my reverse lights start working (amaze!) but the idling problem went away.

 

[SmokingRocks]

I did troubleshoot the MAF, seems to be OK.

I pulled the fuel relay last night and opened it up looked like the contact has a pretty good burn spot on it. Also there was a fair amount of dielectric grease on the connector, without doing an analysis on the grease it seemed as though it had moisture in it as well which is not good.

My plan for this weekend is to get it in the shop so I can unplug all the connectors, blow them all out, clean up the dielectric grease, then dab some new grease in then let the plugs sit out for a day or so. This should get all the moisture out. I will also take a look at the pump and filter. Finally I have a new fuel pump relay, resistor and intake tube on order. Then I'll drive it around and hopefully not have any issues.

 

[SmokingRocks]

Progress...

I took every connector apart that i could reach from the engine bay and under the truck, blew them out, sprayed them with brake cleaner, blew them dry, and applied a ton of dialectic grease. I also pulled my fuel pump relay apart, the contact is severely burnt so I got some 400 grit and ran it through the contact a couple times. Put it back together, lifted it and did the same to all the connectors under the truck. (I also changed my transmission filter and oil as PM but that was outside of this issue)

strange thing is I noticed that the transmission main connector that runs past the starter has been replaced, its a non toyota connector (fuse side ofe the engine the whole wiring harness has been spliced to this connector) basically it looked rough. So I cleaned it and greased it all up and stuck it back together.

Took it on a 2+ hr off road trip today and there were NO problems! I'm hesitant to say that I've fixed it but it seems as though the problem has been addressed. It was more than likely water in a connector.

I still a have new fuel pump relay, resistor and air hose coming in, so I will replace all the suspect parts when they come in.

Heres a video of me playing today:

 

[blkprj80]

Post a pic of that fried fuel pump relay will ya?

Could it have been killed by a bad fuel pump?

 

[SmokingRocks]

Fuel pump is new as of the PO. IDK if I could have grabbed a pict of the FPR, the contact is hard to see with the human eye and only if you looked closely would you had seen that it was burnt. I cleaned it for now but will replace it when the new one comes in.

 

[alia176]

Goats,

This is an EXCELLENT opportunity for all of us to learn from your issues. Would you mind updating your first post in a systematic fashion so that we can keep abreast on what's been tried and the subsequent results? This would save us from reading the entire thread, when another person is on the side of the road and trying to figure things out with two screaming kids, pissed off wife and semis whizzing by at 80mph.

Oh, as far as the gas quality, this has very little bearing on our engines. Third world gas makes this engine run just fine and I've run some s***ty crap through that tank and then beat the fawk out of her pulling a trailer at elevation.

 

[SmokingRocks]

here is a overview of the whole issue and fix;

Day before, I went snow wheeling with a bud and had a great time. (This fact probably has bearing on this issue)

The next day I was leaving to head back home (5hr drive). I noticed several times that while cruising at 75 mph the engine cut out then came back quickly, all gauges normal and new oil so I thought nothing of it. Was climbing out of Denver on US 285 and the first major stall out occurred. Engine just cut out as if it lost fuel. Coasted off to the side of the road, checked everything; Oil - Fine, Coolant Temp - Fine everything seemed OK. So I cranked her over and she fired back up Oil Pressure - Fine, No Smoke out exhaust.

Continued to drive, this stall out happened several more times. Finally got into Fairplay (about two hours after first symptom). Thought it could be bad fuel as I got some cheap gas in Fort Collins (50 cents under anywhere else), so I put a half tank in of good gas. Went to fire the old girl up and she wouldn't stay running. Started up fine, idled fine for 5 seconds - exactly - then cut out. I finally was able to keep her going by holding revs for a bit. Got on the road and started praying that she wouldn't strand me in BFE.

Several stalls later I made it to Buena Vista, stopped to empty my tank, came back out and tried to restart her. This time the start - idle - stall thing happened for an hour. I got my tools out and started pulling sensors out, checking connections, looking for a ground out, twisting, prodding and inspecting every wire. Nothing seemed to work for me. Finally in a last ditch effort I started her up and shifted into reverse... she stayed running.... So I ran for the boarder still having 1.5 hrs to drive.

Got her home went inside and grabbed a drink.

For the next two days she sat in front of my house, not wanting to stay running, thinking the problem was finally persistent I grabbed a jump lead and was going to bypass the fuel pump relay (FPR) and resistor and hard power the pump. I was never able to do this because at that moment she decided to start working again. Pissed off I pulled out the FPR and pulled it apart, the contact looked like it was pretty fried.

So I ordered a new FPR and Resistor. Also I pulled apart EVERY connector I could reach from the engine bay and under the truck including the connector just forward of the left rear wheel (fuel pump power?). I sprayed them all with brake cleaner to displace water and remove dirt then blew them out with compressed air till dry and applied a ton of Dielectric grease. Put all the connectors back together and now I don't have the issue.

Hope this helps someone else.

 

[SmokingRocks]

OK so I haven't been driving my truck much. Its been sitting at home as I have another project on my lift, and as a result the old 80 hasn't had much street time. Its been fairly dry here for a bit however I drove her into work today (30 miles one way) and she was stuttering at higher rpm's while climbing hills n such. I got concerned that it was a reappearance of my original issue however this seems a bit different. I can almost make it happen on command just by keeping the RPM's high and my foot deep in it. Seems like a stutter with the occasional shut off then turn back on.

This is concerning because I was planning on taking her 5hrs away and wheeling up a pretty tough trail this weekend. I guess she got jealous that I was spending so much time on my other project...

Anyone have a suggestion as where to start?

 

[alia176]

I got concerned that it was a reappearance of my original issue however this seems a bit different. I can almost make it happen on command just by keeping the RPM's high and my foot deep in it. Seems like a stutter with the occasional shut off then turn back on.


Anyone have a suggestion as where to start?

I didn't read your entire thread so let me know if this has been brought up already. Can you repeat this symptom by power braking and torquing the engine?

 

[SmokingRocks]

I think I've figured this issue out, however I think this second go around is a different issue than my first issue that had me stranded.

If I fill my tank up then top it off I will get this issue ever time, when pulling grade right after filling up (between 0 and 20 miles away from the gas station) the engine feels like it gets less and less gas like its being starved. It will get more severe until it has to downshift, then will do the same thing until I crawl to a stop. If I stop and chill for a second, then start it up agian its fine.

I have a new charcoal canister (pontiac cheap replacement) and I have a newer gas cap. So I am wondering if the connector to the fuel pump is corroded and when I top off the tank the gas gets on the wires creating resistance dropping the voltage to the pump? Either that or the vent is plugged and the tank is pulling suction. If it was pulling suction or if the fuel sock was dirty this would happen when all the time not just until the tank burns off the first gallon or two.

Looks like a trip inside the tank is in my future.

 

[alia176]

To confirm your theory check the ohms of the pump while tank is full and compare against FSM, just to save you some work?

 

[blkprj80]

You can pull more suction on a larger volume of air. A full tank leaves little room for air.

I'm trying to think how the fuel pressure regulator is controlled. If you unhook vacuum to it, is it supposed to stay at full pressure? It's on the front of the injector rail.