91 FJ80 Intermittent Starting Issue

[sea bass]

I originally sourced from @cruiserdan @ American Toyota but since his retirement from the parts industry and move from ABQ to SLC I source online at:
DAMPER ASSY, FUEL PRESSURE PULSATION. FUEL INJECTION SYSTEM for 1992 TOYOTA LAND CRUISER. #2320746010
If you haven't changed your FPR and fuel sock/strainer, I would order and install it as well. The FPR is on the front side of the rail and as @jonheld mentioned "These items are over 25 years old now. They have served you well" and are really just a ticking time bomb which will cause you issues down the road.

If it is a fpr or a dampener wouldn't it affect all cylinders though

 

[SUMMIT CRUISERS]

If it is a fpr or a dampener wouldn't it affect all cylinders though

Yes and hard starting is the OP problem leaning towards a fuel pressure related issue only at starting. A malfunctioning FPR and specifically a damper will affect this.

 

[sea bass]

Yes and hard starting is the OP problem leaning towards a fuel pressure related issue only at starting. A malfunctioning FPR and specifically a damper will affect this.

Sorry i thought this was another thread where cylinders 1 and 2 were not firing

 

[seatosummit]

Personally, I would replace the fuel pressure damper with a new one. It is a small pressure vessel that serves to absorb the pressure fluctuations in the fuel rail as the 2 sets of injectors fire. Over time the membrane will fail. Tightening the screw will do nothing.
The fuel pressure regulator is another culprit on the fuel rail with a diaphragm that fails over time. These items are over 25 years old now. They have served you well.

Ordered a damper assembly from Toyota of Berkeley. Planning to install Saturday. I'll keep you guys posted.

A

 

[Alleycats]

You'll need a 'crow foot' wrench to install the fuel pressure dampner FYI.

 

[SUMMIT CRUISERS]

You'll need a 'crow foot' wrench to install the fuel pressure dampner FYI.

^^^This^^^ as I recall it is a 22mm. I bought a full set.

 

[seatosummit]

So a quick update:

• replaced the fuel pressure damper (sourced from Toyota of Berkeley)
• replaced fuel pump with Denso unit
• problem persists

You'll need a 'crow foot' wrench to install the fuel pressure dampner FYI.

Sure wish I had read that prior to getting started, I ended up have to make my own in order to finish the job.

I tested the truck for about a week after the pressure damper replacement, before the fuel pump, with no noticeable change in the frequency of the hesitation when starting. I was able to reliably start the truck using @tacoma2002 's method of cycling the key to the "on" position 3 times and then waiting seconds before engaging the starter. Based on this, I concluded that fuel pump check valve was failing and needed replacement.

The following weekend (now two weeks ago) I replaced the fuel pump. It look about 4 hours and was a fairly straight forward undertaking.

Following the installation, and the requisite 10 seconds or so worth of cranking to clear the air in the fuel lines, there was no change in easy of starting. For the first 10 or so days, it seemed the cycling method described above worked reliably to get it started. Now, it takes perhaps 12 periods of 5 second cranking to get it to finally turn over if it is still warm from a previous trip.

The cycling method still works on the first attempt when the vehicle is cold in the morning.

I have not replaced the fuel filter, as I was told it was replaced immediately prior to my purchasing it (12 months ago). Could that be a culprit?

Should I start looking at the ignition system?

Thanks,

Austin

 

[Alleycats]

Just throwing out ideas, but what about the 'igniter' that has caused other no start situations before on similar years 80 series 91-92

 

[SUMMIT CRUISERS]

If you are thinking it could be spark related, I would verify by using one of these or another method: New Automotive Spark Ignition System Tester Flashover Detector Gauge Useful | eBay
Before throwing ignition parts at it.

 

[seatosummit]

The intermittency is the piece that is taking me for a ride.

I am going to talk to a mechanic friend and see if any additional clues point to ignition system.

 

[tacoma2002]

Wow. I'd have bet a paycheck on the fuel pump....

Interested in the final resolution.

 

[Allen9480]

I would replace the fuel filter.

 

[seatosummit]

I had an electrical engineer friend look at it and explained the work I had done thus far.

We took a look at some of the ignition components and found that the spark was a bit anemic with an external plug grounded to the valve cover. He recommended I go through the diagnostics prescribed in the FSM. I am planning to do that this weekend. I will also swap the fuel filter.

I have driven it another 1500 miles since starting this thread, and there seems to be no change in idle, fuel economy, or general performance with the exception of the difficulty starting.

I'll certainly keep you guys posted.

Cheers,
Austin

 

[jonheld]

Before you try starting it cycle the key from the Lock position to the ON position about 3 times. When you cycle to the ON let it sit in that position for about 5 seconds. After you do this 3 times attempt to start the vehicle.

Sounds like the fuel pump is losing prime. If the vehicle starts after this method then you know the check valve on the pump has gone bad and is allowing fuel to back flow into the tank.

Just an FYI, the fuel pump only runs when cranking the starter before the flap in the AFM opens. Turning the key to the on position will not fire the fuel pump on a 3FE.

 

[seatosummit]

Quick Update:

I finally got around to testing resistance on the ignition system per instructions in the FSM.

Primary coil resistance: 0.45 ohms (FSM calls for 0.4-0.5 ohms)
Secondary coil resistance: 12.8k ohms (FSM calls for 10.2-13.8k ohms)
G pickup coil resistance: 245. 6 ohms (FSM calls for 140 - 180 ohms) OUT OF SPEC
NE pickup coil resistance: 240.0 ohms (FSM calls for 140 - 180 ohms) OUT OF SPEC

So, because the failed tests correspond to parts on the low voltage, pickup side of the distributor its not as simple as replacing the rotor and cap, but I rather need to replace the sensing circuitry within the distributor. Does anyone have experience doing this? Easier to just replace the entire distributor?

Thanks,
Austin

 

[82much]

Hi All-

I have a 91 FJ80 that has developed a starting hesitation. It first emerged about three months ago and has seems to have worsened gradually to the point that now nearly every start seems to require about 10 seconds of cranking.

What I know:

• The starter is good (with new contacts) and is properly rotating the flywheel
• The Check Engine Light (CEL) is reliably illuminated when the ignition is in the "on" position
• Though it has an alarm system that is no longer in use, removing the "immobilizer" relay causes the starter to not engage, seemingly ruling out the possibility that the immobilizer relay was wired to interrupt the fuel pump
• After 10-15 seconds, it will start
• Once it starts, an immediate attempt at restarting will always work within 2-5 seconds (normal time)
• Once started, the 3FE will run smoothly and accelerate without hesitation. This includes long drives in below freezing conditions. This makes me think the fuel pump is properly functioning.
• My battery and starter won't last forever

My questions:

• If it was a bad ECU relay, I would be without CEL in "on" position, yes?
• Do these symptoms align with a bad Circuit Opening Relay? Part #?

Thanks for any help on this, Guys.

Austin

I had this same issue with my 91. I had to hold the key in the start position and it would sometimes take up to 30 seconds for the engine to crank. I checked everything! Turns out..it was my battery all along, event though I had above 12V.

 

[jonheld]

Quick Update:

I finally got around to testing resistance on the ignition system per instructions in the FSM.

Primary coil resistance: 0.45 ohms (FSM calls for 0.4-0.5 ohms)
Secondary coil resistance: 12.8k ohms (FSM calls for 10.2-13.8k ohms)
G pickup coil resistance: 245. 6 ohms (FSM calls for 140 - 180 ohms) OUT OF SPEC
NE pickup coil resistance: 240.0 ohms (FSM calls for 140 - 180 ohms) OUT OF SPEC

So, because the failed tests correspond to parts on the low voltage, pickup side of the distributor its not as simple as replacing the rotor and cap, but I rather need to replace the sensing circuitry within the distributor. Does anyone have experience doing this? Easier to just replace the entire distributor?

Thanks,
Austin

It might be possible to replace the pick up coils inside the distributor housing, but they are not available from Toyota. I would search for a good used OEM one and replace the unit.
It is very very unusual for a coil to increase resistance. Typically they will open or short. You may just have corrosion on the coil solder pads inside the housing.

 

[decavo]

try checking the pickups on the dizzy... There are 2 black pickups on the shaft inside the cap.. check to see if they have the correct ohms... That was my issue.... you can use one off of a 4.5 engine they are the same, and how i fixed this issue.... Use the FSM to find the correct ohms,,,, etc...

 

[seatosummit]

try checking the pickups on the dizzy... There are 2 black pickups on the shaft inside the cap.. check to see if they have the correct ohms... That was my issue.... you can use one off of a 4.5 engine they are the same, and how i fixed this issue.... Use the FSM to find the correct ohms,,,, etc...

Thanks, @decavo

I checked the resistance values on the pickups and found them to be out of tolerance. Cool that you can swap parts from the 1FZE. Did you buy new, or find used? Most have recommended steering clear of non-OEM...

It might be possible to replace the pick up coils inside the distributor housing, but they are not available from Toyota. I would search for a good used OEM one and replace the unit.
It is very very unusual for a coil to increase resistance. Typically they will open or short. You may just have corrosion on the coil solder pads inside the housing.

Thanks for this. Noted on the rarity. Are the pads located in the shaft of the distributor? Or are they rather more conveniently located under the cap? If there is a decent method for opening the distributor up, I'd entertain the idea of trying to rework some of the solder joints...

 

[decavo]

Thanks, @decavo

I checked the resistance values on the pickups and found them to be out of tolerance. Cool that you can swap parts from the 1FZE. Did you buy new, or find used? Most have recommended steering clear of non-OEM...




Thanks for this. Noted on the rarity. Are the pads located in the shaft of the distributor? Or are they rather more conveniently located under the cap? If there is a decent method for opening the distributor up, I'd entertain the idea of trying to rework some of the solder joints...

I found my parts at the junk yard.... I am heading home this week end and will see what I have. Look at he had one and head to your local boneyard. Look for the correct size and test the ohms... Bingo you have the part you need. Lots of pieces parts will swap out. I soldered my parts and used heat shrink to deal it up.