Just bought 01 Rodeo 3.2 4wd w/121k miles. Battery was dead, put a new one in and it started. Drove three days, fine. Then it died. When it died the gas gauge went to E. So i tried starting and it was fine. 30 min later it was sitting there running and it just died at idle. Gas gauge on E so I put 4 gal of gas in. Started right up. I drove 1 hr and it died at idle. Just before it died the rps went eratic. Couldn't get it started. Called the previous owner and she said it need a PCM. OK, but before I change it, I tried starting fluid in the PCV intake hole. Started but ran like it was on ether. Tried 3 computers. all have the same symtom. I have put a noid light in 3 of the injector connectors. Nothing. I know I am getting fire at the right time, I just don't seem to be firing the injectors. The Haynes manual list a CMP,(Camshaft Position sensor), which should be in the head around the timing gears. Uh uh. No wires, no sensor. Have had 3 different mechanics look. No sensor. The manual also says this sensor controls the fuel and the timing of the injectors. By the way, all fuses have been pulled and are good. I have removed the fuel pump relay and bypassed to test, it function fine on bypass. Dont know if it is working during crank, (I dont think so), but the circut is okay. I have the original computer back in. Gas gauge is still on E and I know from the wiring that the sending unit feeds the PCM, and then the gauge. I also know that these Rodeos have sending unit issues, but could a sending unit cause the injectors not to fire? No cel or anything, maybe changing has erased any codes. What gives the PCM the signal to fire the injectors at the right time? Is there really no CMP sensor? Can the Fuel Sending Unit make the PCM stop fuel flow? I have oil, antifreeze, it ran fine, what gives? I am at my wit's end with no Isuzu dealer in close range. No one wants to touch this as it is an Isuzu, not even the local Foreigh Performance shop. What do I do? Somebody help, please?

 

Okay, was sad to see no responses in the few days of posting, but good news is it's fixed. I checked voltage at FP relay, no signal from PCM. Checked signal at ECM relay, signal from ign switch. Bypassed ECM relay to back feed voltage to anything just in case, still no injector pop. Looking at the wiring the ECM relay feeds all the injectors a 12V+ signal and the PCM feeds the injectors a 12V- to fire them off. Tested a noid half in the side,(gr/rd wire) from the ECM relay with the other side hooked to 12V-. No noid light. So i checked for voltage. 2.02volts. Wait! It's supposed to have battery voltage. So i looked at it again, yep, the outgoing voltage to the injects was 12V+ but the injectors were only receving 2.02V+. By the way, the ECM relay feeds the PCM input voltage off that same wire. Followed the wire around the front of the Rodeo and found it's first connection between the air box and the drivers fender. (White connector) I checked the Red/GN stipe wire and got the 12V+ going into the connector, (I had to disconnect and test the pin). I put it back together and heard some new clicking at the relay box and back of engine. Looked at the dash and the gas gauge read over half a tank. Hit the key and it started. Took all my bypass wires off and put everything back to normal and have been running since. I had read on this site of a guy whose mechanic found a bad wire in that same area but didn't get the datails I just gave. Maybe this will help someone else. I guess since the computer didn't get a full 12V+ signal from the ECM relay it only half functioned. No fuel injectors, no switched signal to the fuel pump relay, and no fuel gauge. Odd huh? Write feedback and lets hear what others have to say, please. Even if its wrong its nice to hear an idea. What do you think?

 

Okay-driven for a little while. I replaced plugs and regapped. Now I get a CEL only on acceleration during load I get a P0300, cylinder misfire. It seems to be running fine to me. Anything else that could cause this but yet make it run normal?

 

Hi,
I just bought the same 2001 rodeo...the dealer said wiring harness needed to be replaced - the entire thing. 2 mechanics said the PCM. It scares me that you tried 3 of them and it didn't work. Your symptons sound very similar to what the seller told me happened to him. My mechanic owns a rodeo, so I'm hoping that will work in my favor!

 

Well i fixed the misfire. Replaced 2 spark plug boots. Remember the rear right one is a little shorter than the rest to allow for clearance of the brake booster. Someone had mixed it up with the opposite side. Also, one of the boots had a busted spring inside it. Good to go now. Did find a small cchaff on the harness going along the head/rocker cover. That may have been causing the connector to fair(Previously mentioned).

What have you done to yours so far?
PS I only used the 3 CPU's due to professional mechanics telling me that it needed to be replaced. I dug deeper to find the connector problem. I had read about it on this forum at least once before.

 

Good evening...i saw you had a problem with the fuel system wiring and "BY-Passed" the relays, etc to find your problem...how did you bypass the relays, etc?? do you have a wiring diagram for this vehicle?? I've only found a partial diagram on line..sure could use the assistance...
My Rodeo will crank, but will not fire...have the pos. 12V at the injectors, didn't check the Neg 12v...didnt know about that..! I have no fuel to the fuel rail and no indication that the fuel pump is working...all fuses are good and i have swapped out the FP relay with a known good one...i do have +12v at the relay but the pump does not work...over this weekend i plan to pull the tank down enough to get to the FP wiring and try to go from there...ANY assistance would be greatly appreciated...
thanks in advance!! Larryd in Arkansas

 

Where did you use the "Jumper" wires at? I'm having similar problem, no fuel to the fuel rail and it doesnt seem that i'm getting 12v to the pump...have to pull the spare-tire tomorrow and see if i can get to the fuel pump wires at the tank...if you have a schematic for the Rodeo that would be greatly appreciated...or can pass me a web-site...Thanks in advance!! Larryd in Arkansas

 

Sorry this response has taken so long. Wrong log in info killed me for a week! Anyway, heres what I can tell you. Look at the gauges and listen under the hood. If you don't see a fuel level in the gauge or it making electrical gadgets come on under the hood then it is similar to my old problem. If you have a fuel level and the noise then you most likely have a bad fuel pump. I have no schematics I traced everything down manually, what a #itch!