josh2

Hi, I am new to this site and what brought me here is a very frustrating problem that myself two mechanics and even a Toyota dealership mechanic have been unable to solve. So, my truck has run flawless during the past year since purchasing it, but approximately 5 weeks ago the ignition switch seemed to be sticking in the start position, so I spayed a very little amount of WD40 into the tumbler, which worked fine; one day later I came out of work I could hear the "key in the igition alarm" sounding and the indicators for seat belts, oil, brake, and battery where dimmly lit- I started the engine and all the lights and alarm functioned properly. The next day the engine began running really rough at up to approx. 1800 rpm any speed above the engine ran fine-- okay so maybe there were some metal fragments that the WD40 washed into the contacts- replaced the switch and because it was runing rough I replaced the rotor, cap, plugs (NGK) wires, but then after this it idled fine and ran smoothly up to approx. 1800 rpm, then about every 8-10 sec it seemed to miss-used dry gas, fuel injector cleaner and even tried running it without the gas cap for a few miles- problem still existed, so I brought it a mechanic who found that the ignition coil had a hole burned through the secondary insulation and the condensor appeared to be completly melted where the wire come out- coil and condensor were replaced, and even completly checked the air intake tube and filter but the miss problem still existed. Brought it to a Toyota dealership they spent 21/2 hours checking computer(no fault codes) fuel pressure, ignition system, compression, and vacuum lines- all checked out fine, but the mechanic did suggest trying another set of plug wires- I replaced them and even the condensor again, but it still misses and this really starting to upset me!!

My thought is that maybe there is something wrong with one of the fuel injectors or does it seem like it is related to the coolant temp/ fuel- air mixture? Because today it is cooler outside and noticed that it ran smooth until the engine heated up a little bit- maybe after driving 2-3 miles the miss started to happen- it does not appear to running rich. Also, the check engine light only lights when I first start the truck, then goes out- it never came on from the beginning of the problem. Can someone please help me!!

4Voigt's

dumb ? but did you pull the plugs out and visually check them for cracks in the plugs. That could cause an intermittent miss fire.

josh2

Great point, but I have already replaced the plugs with new NGKs.

josh2

I was looking at the engine this morning and noticed that the fuel injectors for cylinder 1 and 4 appear to loose as I can turn them back and forth easily, I put some greases around them thinking maybe air is entering around them somehow- But this did help the problem any suggestions??