In love with my project 93' 80 series but its breaking my heart, bogging down on incline... fuel system issues ? any advice ?

[varnoid]

Bought this beautiful project 93' 1FZJ80 and have been working on getting it reliable for over a year now. It has alway run just fine but i have been chasing demons. I Live on the big island of Hawaii so i need to drive incredibly steep grades very often. to cross the island i drive roughly 6 degree grade for nearly one hour constant. Just driving to town and back to my home i have a much steeper climb and my 80 bogs down even at full throttle. I slow down and climb under 5 miles per hour up hill and it always feels like I wont make it home.

one by one I have replaced the entire fuel system, fuel pump, filters down to the injectors... no change

i thought maybe it was a common (for this year) transmission and ecu communication issue, replaced the ecu transmission solenoids and fluid flush .... no benefit.

thought maybe cats could be clogged so cut them off, welded pipe in

checked for vaccum leaks, no leaks but replaced the intake boot anyway

I have dumped way too much money into this truck to no avail,

next i am going to take it to a shop and have the timing, compression and fuel pressure checked as i cannot find any kits that adapt to my fuel rail with the appropriate banjo bolt

any advice ?

 

[Fj80oregon]

Man if you have done this much work why not do these last checks yourself? Timing is super easy, compression check is easy. Most auto parts store have rental tools for a fuel pressure gauge. Have you adjusted your throttle and acceleration cable per FSM?

 

[effjay80]

Just speaking from Colorado big long elevation increases especially twisty where can't keep up rpm's at speed not a strong suit of my 80. I pull over at times to let mules pass.

 

[baldilocks]

Bought this beautiful project 93' 1FZJ80 and have been working on getting it reliable for over a year now. It has alway run just fine but i have been chasing demons. I Live on the big island of Hawaii so i need to drive incredibly steep grades very often. to cross the island i drive roughly 6 degree grade for nearly one hour constant. Just driving to town and back to my home i have a much steeper climb and my 80 bogs down even at full throttle. I slow down and climb under 5 miles per hour up hill and it always feels like I wont make it home.

one by one I have replaced the entire fuel system, fuel pump, filters down to the injectors... no change

i thought maybe it was a common (for this year) transmission and ecu communication issue, replaced the ecu transmission solenoids and fluid flush .... no benefit.

thought maybe cats could be clogged so cut them off, welded pipe in

checked for vaccum leaks, no leaks but replaced the intake boot anyway

I have dumped way too much money into this truck to no avail,

next i am going to take it to a shop and have the timing, compression and fuel pressure checked as i cannot find any kits that adapt to my fuel rail with the appropriate banjo bolt

any advice ?

What size tires and what gear ratio? Is the coolant getting over 205* on these climbs?

 

[RAYJON]

Check timing, the computer will knock 10 degrees when it senses knock or temp gets too hot.. and it will feel like it falls on its face..

 

[BILT4ME]

Are you manually controlling your gears?

Are you using low range to maximize your torque range on the engine?

Maximum torque occurs about 3400 RPM on this engine. Operate your gears so you are around that rpm on those hard climbs.

If you are really dropping to 5 MPH at WOT, you have a serious issue. You should be in ow range if that is occurring.
Are you heavily loaded (8000 LB?) Tire diameter? Truck modifications?

 

[calokie]

Bought this beautiful project 93' 1FZJ80 and have been working on getting it reliable for over a year now. It has alway run just fine but i have been chasing demons. I Live on the big island of Hawaii so i need to drive incredibly steep grades very often. to cross the island i drive roughly 6 degree grade for nearly one hour constant. Just driving to town and back to my home i have a much steeper climb and my 80 bogs down even at full throttle. I slow down and climb under 5 miles per hour up hill and it always feels like I wont make it home.

one by one I have replaced the entire fuel system, fuel pump, filters down to the injectors... no change

i thought maybe it was a common (for this year) transmission and ecu communication issue, replaced the ecu transmission solenoids and fluid flush .... no benefit.

thought maybe cats could be clogged so cut them off, welded pipe in

checked for vaccum leaks, no leaks but replaced the intake boot anyway

I have dumped way too much money into this truck to no avail,

next i am going to take it to a shop and have the timing, compression and fuel pressure checked as i cannot find any kits that adapt to my fuel rail with the appropriate banjo bolt

any advice ?

EGR or MAF? or the notorious wire harness near EGR burn location?

 

[Reachej]

Have a listen at the catalytic converters, and look for soot marks at the seams nearby and around the O2 sensors. Never know.

 

[varnoid]

Have a listen at the catalytic converters, and look for soot marks at the seams nearby and around the O2 sensors. Never know.

cats have been removed and straight piped through, unfortunately no soot marks near o2 sensors, its hawaii though so the o2 sensors themselves could be toast (everything here rusts to hell and back)

 

[varnoid]

EGR or MAF? or the notorious wire harness near EGR burn location?

very likely, I have cleaned the maf with Maf cleaner, and the truck has a full egr delete, except for that damn near impossible egr pipe, currently capped off but there is a burn on the wire harness. the wires appear to not be compromised but the shroud has melted through. I have not checked the wires for continuity. What issues might be common with that egr pipe harness burn ?

 

[varnoid]

Man if you have done this much work why not do these last checks yourself? Timing is super easy, compression check is easy. Most auto parts store have rental tools for a fuel pressure gauge. Have you adjusted your throttle and acceleration cable per FSM?

I have rented 3 different fuel pressure kits, unfortunately none of them have had the correct banjo bold adapter to fit the fj fuel rail, ill have to order the correct m12x1.5 cp7838 another member mentioned on a different thread, ill have to get a timinggun and have a check i did do a compression check a while back and the numbers across all 6 cil were almost identical but its a cheapo compression tester i was thinking a shop may get a better reading? maybe not needed

throttle cables could be the culprit, ill need to find a FSM and have a read, the cables are loose and not in the stock position in the engine bay, ive noticed that the rpm changes when i move the cable around by hand

 

[varnoid]

Are you manually controlling your gears?

Are you using low range to maximize your torque range on the engine?

Maximum torque occurs about 3400 RPM on this engine. Operate your gears so you are around that rpm on those hard climbs.

If you are really dropping to 5 MPH at WOT, you have a serious issue. You should be in ow range if that is occurring.
Are you heavily loaded (8000 LB?) Tire diameter? Truck modifications?

automatic trans but i did not think i would need to go into low gears on such a short hill up to my house, i cannot find the original video but i posted it on a FB group a while back, ill link the video of the truck going up this short hill.

video i posted driving up the hill to my house


the truck is unloaded not towing anything at all tire size is 26517r16 and the truck is bone stock except for egr delete.

i will try the hill again near 3400 rpm in low gears and see how it handles

 

[Fj80oregon]

FSM - 1993-1994 FZJ-80 Updated and Combined FSM

IF YOU ARE HAPPY WITH THIS FSM PLEASE RATE THIS RESOURCE 5 STARS! Revision 05 has been uploaded, check out the update I posted detailing the new features added. The previous version of the 93-94 FSM had confusing file names, ridiculously...

forum.ih8mud.com

 

[Fj80oregon]

Here is a digital copy of the FSM you can download for free!

 

[Fj80oregon]

That’s great you have even compression! Get your engine warm and make sure to follow the steps for setting the timing, only a 10 min job. If you are just driving normal roads no need to be in lo gear your cruiser should be able to climb a hill or like posted above you have some stuff to figure out. You can definitely try in lo gear on normal roads just be aware you are not going to gain a lot of speed as the gearing is much lower. Why are your cables not in the stock positions?

 

[BILT4ME]

automatic trans but i did not think i would need to go into low gears on such a short hill up to my house, i cannot find the original video but i posted it on a FB group a while back, ill link the video of the truck going up this short hill.

video i posted driving up the hill to my house


the truck is unloaded not towing anything at all tire size is 26517r16 and the truck is bone stock except for egr delete.

i will try the hill again near 3400 rpm in low gears and see how it handles

Can't view the video.

 

[Broski]

I have a 94 on 39” tall tires I just got back from Colorado where I was able to maintain speed with regular traffic 30 to 50 miles an hour on steep mountain passes 9 to 10,000 feet.
Manual shifts are necessary and 35 to 4000 RPMs don’t be afraid to rev the motor.
Low range was not necessary.
Turn overdrive off.
And keep the ECT button smashed down.

 

[calokie]

automatic trans but i did not think i would need to go into low gears on such a short hill up to my house, i cannot find the original video but i posted it on a FB group a while back, ill link the video of the truck going up this short hill.

video i posted driving up the hill to my house


the truck is unloaded not towing anything at all tire size is 26517r16 and the truck is bone stock except for egr delete.

i will try the hill again near 3400 rpm in low gears and see how it handles

unfortunately unable to see video,... you have adjusted the kick down cable? What if at the bottom of the climb you let off the gas let the RPMs drop then press the gas at the bottom of the climb allowing the transmission to drop back down into a lower gear?

When you cleaned your MAF did you remove it or adjust anything?

Have you checked your rubber intake hose that goes from your air filter to throttle body? I have heard of those cracking and causing issues.

 

[varnoid]

Can't view the video.

Noob question but what

unfortunately unable to see video,... you have adjusted the kick down cable? What if at the bottom of the climb you let off the gas let the RPMs drop then press the gas at the bottom of the climb allowing the transmission to drop back down into a lower gear?

When you cleaned your MAF did you remove it or adjust anything?

Have you checked your rubber intake hose that goes from your air filter to throttle body? I have heard of those cracking and causing issues.

Ill Adjust the kick down cable asap but have not adjusted yet ! Ill have to let the truck and trans try to shift to a lower gear and see how she handles it, the main road i am concerned with is going alteast 50 up a highway that basically starts at sea level then climbs to 6765ft then back down to sea level haha a bit ridiculous.

when I cleaned the MAF the only parts removed were the hose clamps to access.

I also have a brand new intake boot, about 2 miles on it so far, the previous boot was a bit cracked.

 

[varnoid]

I have a 94 on 39” tall tires I just got back from Colorado where I was able to maintain speed with regular traffic 30 to 50 miles an hour on steep mountain passes 9 to 10,000 feet.
Manual shifts are necessary and 35 to 4000 RPMs don’t be afraid to rev the motor.
Low range was not necessary.
Turn overdrive off.
And keep the ECT button smashed down.

noob question but do all fjs come with an O/D button ? my O/D light came on recently yet I cannot find the switch anywhere.

Right now the truck is incapable of driving over 40 mph up hill, right now I can barely make it home to about 1000' any faster than 10 ish MPH