Hi All, My Rodeo with a 2.6 l 4ZE1 fuel injected engine runs rough not long after it has started up-barely warmed up to operating temp. I've done the various tests that the after market workshop manual suggested. It does not idle properly-sounds like it has a cylinder out, it has a flat spot and seems to have a cylinder out up to about 2700-3000 RPM, above this seems ok-(stationary) On test drive it breaks down under load. So far, I have removed and cleaned the fuel injectors and fitted service kits, replaced the Throttle position sensor and set correctly, replaced the crank angle sensor and timed distributor/timing, adjusted valve clearances correctly,and replaced the oxygen sensor. All have made variously good improvements. I carried out a voltage check on the Mass Air Flow meter and when the engine began running rough the signal voltage at the MAF meter dropped and so I have just replaced the MAF meter with no improvement. I have checked and ensured that the ECU is grounded at the mounting bolts. I cannot find a plug to try and get codes. Does anyone have any clues as to what it could be causing these issues please? Cheers.
When it sounds like a cylinder out have you removed spark plug leeads one at a time to identify which cylinder? Add spark plugs and leads to your check. Beyounfd that low compression cylinder worn cam etc bad ecu or bad ignition module in distributer
Thanks geeves, I forgot to mention the plugs and leads-all replaced. The thing is, the engine runs as sweet as when cold. I haven't driven it cold to know about the load drive check though. I haven't pulled the plug leads when it is running rough but should do that. I'm thinking about the voltage drop at the MAF meter when it runs rough-when I checked the signal voltage it went below 1.0 volt abruptly at idle when rough. My thought is, I wonder if the ECU power or earthing to the MAF was interupted and being the cause?! Therefore an issue with the ECU. I have also replaced the coil. It is so hard to get information, a very detailed schematic of the wiring and the ECU internal wiring/build up would perhaps be of some help.
Hi All, Just coming back with more information. Have checked the MAF meter (New/Recon) and the voltage from the ECU is constant to the MAF-11.8v with ignition on and 13.07v whilst running. The earth back to the ECU is good and constant and the signal voltage smooth and constant at idle and smooth to higher RPM's. The engine still runs rough at times, not working on all 4-sprayed lanox on exhaust and numbers 1 and 2 were wet when running rough. then it would be ok and then rough. still has flat spot as you touch the throttle even when driving. On the test drive it would come good sometimes. Cheers.
Thanks, but no, they are not easily swapped around. I've just read in the after market workshop manual that there is a Diagnostic Harness-(which consists of two wires near the computer/ECU. Not sure what colour they should be. According to the manual, if I join these wires with the ignition on the check engine light on the dash will flash any codes. My next step is to atempt this and see what comes of it. I guess that's the down falls of the earlier fuel injected vehicles-there was no OBD II connectors! Cheers.
Thanks, but no, they are not easily swapped around. I've just read in the after market workshop manual that there is a Diagnostic Harness-(which consists of two wires near the computer/ECU. Not sure what colour they should be. According to the manual, if I join these wires with the ignition on the check engine light on the dash will flash any codes. My next step is to atempt this and see what comes of it. I guess that's the down falls of the earlier fuel injected vehicles-there was no OBD II connectors!