thecole1098
New member
Hi all, I'm back in this part even though I don't own my 3rd gen anymore. Just got done with a road trip to Hot Springs, Arkansas for a wheeling trip up there with me and my 2 brothers. I hauled my XJ with my 06 4Runner and my brother followed with his new to him 96 4runner (my old one). Way there went great and both vehicles did fantastic off road and took a hell of a beating during the process so I was impressed. Fast forward to going home, things were not so smooth. About 2 hours away from home, I see my brother put on his hazards and pulling to side of the freeway. Shit. He said that it started shifting really weird (like downshifting going downhill), surging, loss of power, then died as he was coming to a stop. I could smell a strong sulfur smell so I thought the cat gave up the ghost and was restricting the exhaust majorly. So we removed the upstream o2 with it still plugged in and attempted to start it. It cranked then sputtered and ran for like a second then died again. Tried again. Cranking but nothing else. Few minutes later after looking everything over I heard a fast clicking under the throttle body with the key on, but stopped when key was off. Had key on and unplugged IAC, boom it stopped. Okay, so it's the IAC. Fair enough, it's original. So we run to the nearest part store 30 miles away to get a new one. Battery was disco during all of this btw. Plug battery back in once new IAC was installed, turn key and crank crank crank sputter then nothing. What the hell! The IAC was clicking just like the old one too. I could smell a ton of fuel in the engine area too everytime we cranked it. I called it a night and wanted to get the hell home so I let my brother drive the XJ back home and pull the 4runner up the trailer with the winch to get it home.
A good night sleep later, we decide to take another crank at diagnosing the runner. Tested for spark, it's getting it. Defintley getting fuel as I can smell it strong. I start thinking maybe its the ECU. Weird shifting, IAC clicking fast, ton of fuel. For shits and grins, I decided to disco fuel pump connector and spray starting fluid directly into throttle body while he opened throttle and cranked. After a bit of starter fluid, it runs for a little bit! Sounded like a lawnmower engine with o2 removed though lol. So I've come to the conclusion that the ECU is sending a shit ton of fuel and flooding the engine. Is my diag pretty sound in thinking its the ECU that's shit the bed? I suppose it could also be a stuck fuel pressure regulator.
A good night sleep later, we decide to take another crank at diagnosing the runner. Tested for spark, it's getting it. Defintley getting fuel as I can smell it strong. I start thinking maybe its the ECU. Weird shifting, IAC clicking fast, ton of fuel. For shits and grins, I decided to disco fuel pump connector and spray starting fluid directly into throttle body while he opened throttle and cranked. After a bit of starter fluid, it runs for a little bit! Sounded like a lawnmower engine with o2 removed though lol. So I've come to the conclusion that the ECU is sending a shit ton of fuel and flooding the engine. Is my diag pretty sound in thinking its the ECU that's shit the bed? I suppose it could also be a stuck fuel pressure regulator.
