Still cutting out

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Joined
Jan 13, 2005
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Boise ID
Trying to figure this problem out because I have a feeling it is going to leave me on the side of the road one of these days.

Driving home today the engine started to cut out. Was going about 35 and the engine just starts to cut out. Put the pedal to the floor and it stumbles for a while then takes off and runs fine. Really only happens when the RPMs are low and once it gets aboe 2K it runs like a top.

The idle is also rough. When I first stop it idles smooth and perfect then gets worse and bumps between 400 and 600.

Things I have replaced are cap and rotor, soon to be fuel filter, took the fuel relay out and cleaned it off with the match box. I am about ready to order a new fuel pump and see if that helps out.

Any Ideas will be great, since this is my DD and about 45 miles a day (I know gas is killing me) I cant afford to lose her on the side of the road. Here is a little pic to show what I am working with
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Its starting to do it more consistently now. On my way home from work it started acting up again and this time for a longer and I actually could think about it for a while.

I will check out those other things guys thanks for the help.

What happened was the pedal was to the medal and the engine wanted to go but felt like it was getting flooded out it just wasnt accelerating and was actually decelerating. Every once in a while it bounced back accelerated then chugged. Did this a couple of times before coming back to perfect.

with this happening I am now thinking that it is the spark that is the problem. Since if it was the gas it would just die then pick up because none of the cylinders were getting gas. Im thinking some of the cylinders are struggling getting a good spark and this would cause the rough idle also.

After checking the things mentioned above I think I will get new plugs, wires and thinking about a new ignition coil, would this be a good idea or not? Is there any relays I can check?
 
I would check all your intake hoses to make sure there is no air leaking in past the MAF. What year is your cruiser?
 
yes it would. As the motor moved on the motor mounts it cold expose a vacuum leak that would not normally be present. and the rougher it idles, the more the vacuum leak will be. causing it to run even worse. this is a more common issue on the FJ80 in '91 and 92' models, but i see how it could be possible to see it on a '93 or newer FZJ80 also.

You can also look for a vacuum leak by spraying some starter fluid on some of the vacuum lines and intake. listen for an increase in idle speed and you can locate it that way.
 
Checked the hoses and couldnt find any leaks re-tightened everything and no change. I am thinking a vacum leak would just cause it to run rough and not to cut out and stop running for a few seconds right?
 
Try while in reverse, if engine runs fine in reverse check your wiring harness.
 
The PO said that the wiring harness was re-done where it gets burned up Ill try in reverse hope it isnt a wiring problem.

Wouldn't be the first that had a recurring problem here. If you didn't repair it yourself then you should start there.

-B-
 
It runs the same in reverse as in forward. What is strange is that it doesnt happen all the time. It is sporatic when it acts up. When it runs it runs perfect and strong. Going to change the plugs and wires tomorrow and see what that does.
 
Wiring harness

Open the wiring harness yourself. Make sure the wires are well insulated and do not forget to wrap with heat tape when you finish. You said when it runs it runs well so do not waste your time on plug wires and plugs till the wiring harness checks out.

The "Factory Tape" may seem to look OK, but once you touch it you will know why it requires attention.

https://forum.ih8mud.com/80-series-tech/218351-how-protect-wire-harness-near-egr.html


This one is a great visual!
https://forum.ih8mud.com/80-series-tech/169319-melted-engine-wire-harness.html
 
It has gotten a lot worse :o


coming home from the airport it start to do its thing again. This was the longest it has gone on for and I even had to pull off to the side of the highway.

No matter what I did it would no accelerate over 40MPH the revs would increase but nothing would happen. It wouldnt accelerate but was able to hold steady at that speed. I pulled off to the side of the road and it would still idle. During this hole thing it did not die at all.

After letting it sit there idleing for a while it ran fine and got me the rest of the 20 miles home.

I really cant figure this out and it is getting frustrating. the wiring harness has all new tape on it and looks like it was actually re-done.

Im back to my first thought of fuel pump. Is there a way to check it with out have to pull it out?
 
It has gotten a lot worse

I really cant figure this out and it is getting frustrating. the wiring harness has all new tape on it and looks like it was actually re-done.

I realize the main engine wiring harness can be intimidating but you need to 100% eliminate that as the cause of your problems. As we have been trying to tell you, your symptoms closely match the symptoms of several others that have had problems with the main engine wiring harness in the area where it passes by the EGR valve. Looking at the outside is not an adequate way to eliminate that as your problem. The fact that it has been a past problem on your truck and that someone has already been in there means this is something that you have to check.

There is a recent thread where we gave the OP some diagnostics on the fuel pump which included a wiring diagram and the testing procedure from the FSM. SEARCH for that thread. I believe the guy found a bad connection at the pump. The thread was within the past 30 days so it should be easy to find.

Have you checked the fuel pump relay? Have you checked the big tube that goes between the air filter canister and the intake?

Coil and igniter are other possibilities. Check the white wire between the alternator and the battery and from the battery to the main fuse box under the bonnet. That is the power to the ECM and you have to have that for the truck to run. Outside of these, I have no other suggestions.

-B-
 
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I will tear into that main wiring harness tomorrow hopefully. The air hose is good no cracks, brand new wires, plugs, rotor, and cap. Cleaned the Fuel pump relay. I found that thread talking about the fuel pump Ill try that tomorrow also.
 
Wire harness is perfect no melting at all. It was even re-routed so it doesnt touch the EGR tube anymore. Looks like it is tucked in to the left closer to the valve cover.

Could this problem be EGR related. I remember reading that this might happen if that EGR tube is plugged?
 
Could this problem be EGR related. I remember reading that this might happen if that EGR tube is plugged?

Give us a link to where you read that the EGR tube might cause your symptoms. I do not believe that it can cause anything like what you have described.

Start looking at the other things that I mentioned unless someone else has another suggestion.

-B-
 
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