Pirate the '88 FJ62 Build

[taylorqj]

@diesellibrarian I set timing per your recommendation and my idle dropped to a still-not-normal 800~ which is much better than 1100-1200! I’ll be doing valves soon. Maybe a slight change in the stumbling, bogging, and backfiring.. less pronounced but still happening. Thank you.

I went through with a multimeter and tested the ICV, TPS, and AFM.. all testing within spec. Picked up a vacuum gauge and it’s reading around 18-19 Hg at idle which seems in the normal range. Stabbing at the pedal it would fall but come right back up, giving it steady input it mostly stayed the same.

Thinking I’ll check plugs, wires, do a valve adjustment, and then maybe pick up a fuel pressure gauge. Really wanted to take this thing out camping this weekend. Bummer.

 

[diesellibrarian]

Yeah valve clearance is critical. These old tractor engines will run even if the valves are way off, but they won't run well. According to the FSM, valves should be adjusted every 15,000 miles or 18 months, but I would bet that a lot of rigs will go years or even decades without one. I've noticed a marked difference in how my F engines run after a valve adjustment.

I think you mentioned that you'd checked the hose between the MAF sensor and the throttle body, but my advice is to remove the hose from the vehicle and give it a really thorough inspection. I've found large cracks in that hose that were not visible when it was in place on the rig. I think that replacement hoses are available through City Racer and probably other vendors. An air leak in the intake hose is mentioned a couple of times in the FSM as a possible cause for the symptoms you're experiencing.

 

[taylorqj]

I think I have narrowed it down to the fuel pump, which is funny, as it was "working properly" before I started replacing all the fueling parts. Tried ordering the LCE Fuel Pressure Bolt Kit but fulfillment was taking forever so I picked up a Maddox fuel injection service kit at HF that includes a M8x1.0 banjo bolt to place a gauge at the cold start injector. Works perfectly and you get a full kit for other vehicles for around the same price as a gauge + bolt.

I'm getting about 37~ PSI at the gauge when idling and sharply dropping down to 15-20 PSI under any sort of load. I've put 12v directly to the pump via the +BP + FP short and experiencing the same thing. My best guess is that we have a weak pump.

Idling (cold)

Under load (Reading just under 20)

Looked for a Denso pump and couldn't find anything in stock so I sucked it up and bought OEM pump (23220-16190), filter (23217-61010), and related accessories. Will be dropping the tank and inspecting the hanger.. maybe I'll get lucky and it wont be rusted out

Did some other maintenance like replacing distributor cap, rotor, and plug wires.. then some power washing before I take the tank down.

 

[taylorqj]

This build has quickly turned into fixing issues rather than building.. at least we’re refreshing parts.

I dropped the tank and replaced the fuel pump + refreshed the tank hoses with a kit from @cruisermatt (thanks dude!)

Unfortunately still having the same issue, it does seem less pronounced, but fuel pressure is still dropping sharply under load. Super bummed. Thinking I need to test voltage under load now.. maybe something going on there.

 

[toy_tek]

Or the new regulator is failed.

 

[taylorqj]

Or the new regulator is failed.

Not impossible but I’ve tried both the old and the new one. Worth another test.

 

[taylorqj]

After replacing just about everything I can think of and some things twice, I found the culprit.. a burnt up, crusty, and somewhat working engine harness. I chased fuel pressure from the rail all the way to the tank, triple checked all spark, and made sure vacuum was good. I knew the harness wasn't in great shape just from the look of the wrap but didn't consider it being an electrical issue due to the truck starting and driving well without any load. I peeled back the wrap and found that it was badly burned and one of the injector wires was completely mangled. Tbh I was shocked this thing was running at all.

I sent it off to cruisermatts to be rebuilt with all new connectors, new wire, etc. and they did a fantastic job.

Plugged everything back in and ITS ALIVE.. just in time for summer. Starting to address the steering issues.. ordered a full 555 kit and will likely get into the brakes. So happy to be driving again.