Still cutting out

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

i found that link on here I will search again. They did something like disconnect it and see if it got really hot with being disconnected and if it did then it was blocked.

I did take a lot more time yesterday cleaning out the fuel pump relay like 5 minutes on each side of the bottom contact. It is running a lot better on acceleration but still does the same thing at idle.

Im kind of back to the fuel pump idea now. The chasis has 208K on it and the engine has 80K. Im thinking that it is the stock fuel pump and after that much mileage it is getting tired?
 
I cant find that thread I probably lookd through 30-40 threads last night trying to get some new ideas to check.

I am going to check the wire from the alt. to the battery then to that main fuse box right next to the battery.

The weird thing is that this entire time the CEL has never came on or flashed and it does work becuase it lights up when the key is on.
 
thinking about it it could be the tranny but I looked over that one becuase it shifts really well when not doing it. Nice tight crisp shifts with the ECT on, ATF fluid does not smell burnt and is at the proper level.
 
Reading this thread, all I could think about adding is to replace your fuel pump relay. The match book trick works good for a trail fix to get you home. But after sanding and moving around the contact arm, it should be replaced. I was never able to sand the contacts without bending that small arm a little off center, and now your contact surface is not smooth or clean so it will oxidize over again fairly quickly.

I agree with most here that you have some sort of elctrical problem. When your truck runs perfectly well between episodes, a part like bad spark plugs doesn't all of a sudden fix itself. I personally have never seen a fuel pump work great one moment and then crappy the next unless it was an electrical problem (bad ground) verses the actual pump burning up. If the pump can support full throttle acceleration, then the pump itself is probably good. Someone here may have had an experience which contadicts my fuel pump dying history, but either way, I would look at all electrical possiblities first.
 
Reading this thread, it sounds to me like a faulty MAF, now I don't have any toyota experience but I have worked for both Honda and Nissan. So I don't know what's common or uncommon on a toyota, but it really sounds like your MAF is flatlining...I guess there's no good way to check it without a scanner, but it sounds to me like you've been throwing parts at it anyway.

My opinion is take it to someone who knows how to diagnose it and repair it. You will have to spend some money, but you've already spent money on a distributor cap and rotor and fuel filter etc.
 
If you haven't checked the EGR lines and tubes do so. I doubt if this will solve the whole problem but may help.

My 93 had a sparadic low idle problem that eventually became full time. After exhausting most fixes found on this forum I had no luck. This went on for a year and a half. I never checked the EGR system because I never got a CEL. Then I found a thread that mentioned that the 93 does not throw a code for EGR system as there is no sensor used. I found the intake tube and lines were plugged. Once cleaned the idle problem dissapeared
 
I was thinking about the MAF but didnt really know how to check it besides just cleaning out and hoping. I got a brand new fuel relay on the way since cleaning the old one helped out.

68fj40 what lines did you clean exactly? and were are the located?
 
Check post # 3 in this thread : https://forum.ih8mud.com/80-series-tech/189044-egr-picture.html

The EGR valve is circled and the Modulator is to the right. Check all vacum lines to the modulator and EGR valve. Check all the ports that the lines hook to. Especially check where the line connects on the tube at the intake manifold.

The top of the modulator comes off and you can clean out the carbon inside if it has built up.
 
Ill check that out, blow out those lines.

I am doubting that they are bad enough to cause it to periodically cut out seems like if they are plugged it would be a consistent thing. Thanks though I will check it out.
 
Same kind of thing

I have a 1991, just in the last couple of weeks it has started acting similar. I took it to the mountain with the family no serious stuff just dirt roads ran fine the entire way out but on the way back home almost 80 miles it would chug the entire way. I would push on the gas it would start to go and then it would bog out. I had to limp it all the way home. So should I start with the wiring harness or the Throttle positioning sensor?
 
MTN HOME TLC said:
So should I start with the wiring harness or the Throttle positioning sensor?
Click to expand...

The 3FE engine does not have the same main engine wiring harness issue that the 1FZ-FE engine has in the US market. In the US, we get the EGR valve and this wiring harness passes right next to this and it gets extremely hot and melts wires.

You really should start your own 3FE specific thread here in the 80-Section regarding your issues so the guys that know that engine will see your request for assistance.

-B-
 
Since I really took the time to clean the relay it has been running really well. It accelerates better and has not had another episode yet. I ordered a new one from Cdan and I am hopeing that this will take care of my problem.

My concern is that will this relay casue the engine to stumble at highway speeds (65-70) and could this actually fix the loping idle?

In a few days I hope we can put this thread far behind us and only look back upon it.
 
Hasnt done its little thing in a while (knock on wood) but now it has decided it wants to idle at 400 or 200 rpm when warmed up. It doesnt even want to stop at the normal 600 it just keeps dropping down to 400 or 200 and then starts the up and down and up and down loping idle. I am thinking this could be the TPS and they are freaking out sometimes causing the stumble and hard to accelerate?
 
You can test the TPS with an analog voltmeter. It has to be analog, with the old school needle.
Backprobe (probe the back side of the connector while it's still plugged in.) the signal side of the TPS connector. It's easier to do this with a T-pin and the meter's aligator clips. Slowly move the throttle from closed to wide open and back. Observe the needle on the meter. It should sweep smoothly from closed to wide open throttle. If it does, it's probably ok. If there are any drop outs, the sensor is shot.
 
Quote:
Originally Posted by jonheld
Check the intake plenum for cracks.

x2 check the intake for cracks. It's more common than one would think.

Yup, I found out that mine completely broke off. I didn't see it before because the rip was at the bottom of the ripple thingy. I temporarily tape it off and the idle is normal again. Thanks for everybody whose make those comments and suggestions.
Boy, I wish all trouble shooting is this easy.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom