So I'm tracking a couple of small but annoying issues. I'l create a single post on each to track its progress.
- Stuttering around 1800-2000 RPM occasionally
This seems to be a common issue. some write up hear and in my local facebook groups. Strange that no direct fix has been found and instead lots of different things have been tried, but no one actually saying the issue went away, except some who have replace nearly everything. For me, it really only happens when car is warmed up, and on a trip. It only happens on slight inclines (hence slightly more throttle), does not seem to happen on normal flat surface or down-hill. It does not happen all the time (I can go on trips and not have it), but anything over 30ins i can normally feel is, and it will stay for a while. When it starts you cant floor it through the issue, however changing to a lower gear gets around it (RPM goes up to 2200-2500). It sometimes gets a big stutter, shaking the whole car (you loose all accell for like 1second), but then goes) , other times its is just a slight small cough. Possible related issues. After a long drive, idle RPM drops to under 500rpm (normally 650rpm), also engine does have a burble at idle (its not rough, but its not perfect, but I've never heard another 62, so it could be normal), Tacho occasionally decides to stop working and issue was present since i bought the car (hence nothing in the rebuild fixed it).
i thought it was originally spark related, but others think its fuel related, or air getting in somewhere?
Here is the list of things I'm going through to try and fix it. I generally do a couple before a long test drive.
- Emisions computer : DONE, not replaced, but re-soldered all connections
- Spark connections Grease: DONE
- Better Spark Leads: DONE
- New Fuel Filter: DONE
- Hotter Spark Plugs (looking not best): Not done yet.
- Bypass EGR Valve: Dont have one in a FJ62 Aus edition
- Green Wire Mod/Bypass Idle Cut off: aus 60's dont have green wire, but the cable can still be jerry riged to bypass - DONE
- Swap Canister Pipes? : Not sure what canister? Only have 2, and they each have different size slots
- Drive without fuel cap?: DONE
- New PCV Valve? - instaled
- Replace Disti Rubber Vac Pipe? (5mm) - DONE
- replace all Vac Pipes? 3.5mm. - DONE some
- Check Idle Cutoff (12V and Switched Ground). Remove and clean, tested and work - DONE
- Vac Problem/hole in intake manifold? (spray carb cleaner, around it while running?) Check when really hot?
- Replace 4 short Vac tubes back of Carb?
- disconnect tacho cable from coil?
- replace intake manifold gasket? Big job
- Could be related to fuel level issue in tank? Vapour lock etc: Not sure how to test
- Replace entire Carb
update 3rd Sept.
- Still happening. Thought it might be spare but replaced most of those parts? Could still be emmissions computer, but not sure how to test. It was not super bad, but issue kicked in after 30min of driving and prob occured about 1/3 the time on small inclines. Going to try idle valve bypass, and test for vac or manifold holes.
update 15th Sept.
- Still happening, seems to cut in when car warms up for a while (not just operating temp, but needs to be under a little stress). The idle-cutoff mod did not work. Itested the solinoid and it was working fine. I installed another PCV valve. When I removed the old one I could blow/suck air both ways, but the new one is a one-way only valve so it was definitely failed. Also when replacing vac tubes, I wanted to test the idle up valve. It's stuffed, when testing on 12V its not doing anything., a new one is on order.
Update: 19th Sept.
- its Hot, 35 outside, so took car for a round town trip. No evidence of any of these issues, but it was 40mins of city driving. Each time previously its been highway driving for hours then the problem occurs. Will re-test.
Update 26th Sept
- Some small drives, its still happening. It shows most when going uphill, around 1800rpm in 3rd or 4th gear. Its not as bad as it was, but I've found a hill that makes it happen. Trying to think what mechanisms are changing when these things occur. The engine is under load (hill), RPM 1800 about!. When engine is under load, Vavuum will increase. That feeds the Disti vac advance? I wonder if thats the issue. I've bypassed the green/white wire mod on idle-cut off as that has a trigger at 1800rpm. I think next I might give disti a good clean, and maybe even try electronic points! It seems petronix make them and they are on
ebay, but lots of mixed messages if they fit. Alternative, replace entire disti with an electronic one, but having trouble finding one.
Update 3rd Oct
- Pulled Disti Cap and Roter. They were both heavily clogged, the rotor was pitted so I cleaned with emry paper. The cap had white crud and pits on each contact, so I replaced entire Cap. I also tested the Vac Advance (basically sucked on the pipe) and was getting nothing Had to do some researched on how it worked and found that it 'twists' the entire contact assembly, and I was able to actually 'twist' it ok with fingers. I then repeated the suck test and I was moving? I guess I may have unstuck it a bit. Sprayed whole lot with contact cleaner. Also the 'Suck' has a possible leak. i.e. sucking moved the points, but the pressure then drops and they move back. This is possibly meaning the system has a leak, but I also guess that any vac from the carby is likely continuos, which means it would work. Time to do a bit of research. Went for a test drive and the whole truck has more life now! A tad more power, couldn't reproduce the fault, and it also idles 100rpm higher (which I wanted it to do, as I always thought it was low). I wont say its fixed yet, but I'll take it on a longer drive. Seems like a new one now! I guess I should have looked at this a while ago. NOTE:The disti-clips, have an angle clip on the bottom of the clip, that unless you pull it out you wont notice and think you messed it all up, but when you pull the bottom clip out it all makes sense and goes back easily.
Uopdate 14th Oct.
- Going to call this FIXED. Had a good run today, and zero evidence of this issue. No stuttering around 1800rpm on hills. I think either the Disti Vac-Advance being stuck 0R the crud on the disti rotor and points. I think the Vac is more likely as they will change depending on throttle and performace. I'm not sure if it was locked on or off, but the way to test is to disconnect vac tube from Carby and Suck on it. If the disti moves your good is not, they give it a push/WD40 etc to get it free. Best of luck everyone. This issue affected quite a few people.
Update: Feb
- Nope, still occurs. certainly not as much, not every time, but when it decides too, it happens. Definitely only when car is quite warm. Apart from replacing things like Disti/Carb I'm not sure what to do.