deanshark

When you pulled that plug (#7) did the plug have fuel on it or smell like fuel? That way you would know if the injector is working or not. If you ran the car without that spark plug in I would think that fuel would have spit out the spark plug hole.

atropine

I didn't smell any fuel on the plug. I didn't see or feel any fuel spitting out the spark plug hole. I just bought on oscilloscope and will recheck everything this weekend. So I should hear "clicking" when I place the oscilloscope directly on the injector, correct? If the injector is plugged, will I still hear a "clicking"? Just trying to determine if I should be thinking about buying a BG pressurized injector cleaner kit, or just be thinking about maybe a new injector... Of course I will wait until I do a little more testing to decide.

deanshark

Well, if you didn't see or smell fuel, that aint good. When I had my plugs out and cranked the engine, I had fuel spitting all over as far as the fender. Yes you should hear clicking and it will still click if it's clogged b/c it's still getting electrical pulse. If it's not clicking that doesn't mean the injector is bad, it could be a problem in the wire harness. Are you sure the electrical connector is plugged in tight?

radiohound

well, I changed the ECT sensor...what a PITA ... and I am an experienced, if rusty, mechanical type ... The old was looked terrible and may have not been working ...

anyway, replaced the thing ... also cleaned the Throttle body and plenum .. lots of crud in there ...

anyway, it seemed to improve things ... but still hesitated and bucked ... next step ... I am going to swap out the ECU and the fuel pump from a wrecked lexus at the local pull a part ... I am about wits end ...

Right now, the car is in the garage with the battery disconnected.. I am trying to clear the codes so I can start again tomorrow ... with a fresh palatte of codes and trouble shooting.

appreciate your thoughts and suggestions.

atropine

PROBLEM SOLVED!!!!

Listened to my injectors with an oscilloscope this morning, they all sounded the same (good clicking all around). So I removed spark plug # 7 again and ran the car with an open spark plug hole. No fuel being spewed out, and spark plug was sparking as appeared to be appropriate while attached to the spark plug wire. So I was suspecting that the fuel injector was just clogged at this point. But I decided to check the next cylinder to see how it compared. When I ran it with the spark plug wire disconnected, it was running way worse (now running on 6 cylinders instead of 7). Removed that spark plug and ran the engine, but no fuel spewed out of that hole either. So now I was stumped. Maybe it was a spark issue instead of a fuel delivery issue. So I decided to just replace the #7 spark plug anyway (it was only $5). Got a new spark plug, put it in the #7 cylinder, fired it up, and WOW, what a difference. Now I have a buttery smooth idle and no hesitation anywhere on acceleration. Much better power and much healthier sounding. I suspect that I have had just poor spark this whole time that somehow improved with increasing rpms. Interesting that the engine would even run as well as it was on 7 cylinders. Also interesting that the previous owner had replaced all the spark plugs and wires within the last 10,000 miles. Curious that I would get some incremental improvement with replacing the ECT sensor and then the crank sensor, all the while with a bad spark plug. Will see if things get worse in the future. If that spark plug goes bad again, any ideas why? THx again to everyone for your help. Radiohound, hope your problems get resolved as well.

atropine

i also tested the resistance in the #7 spark plug wire. it was 1.28k ohms, which seems to be well within acceptable range according to other info i have gathered from this site.

atropine

I keep thinking of a couple little details to add: I replaced the existing spark plug with an identical Autolite 3923 Double platinum plug.

radiohound

so I changed out the Main Computer with one from a traction controlled car. Mine is not Traction Controlled.

Anyway, the hesitation I've been experiencing immediately disappeared. Hmmm. I ran it for a while but it seems to be all good, so far. I am a bit leery of declaring success. Anyway, here is the list of things I changed without making a difference:

Wires and plugs
rotors and caps
Fuel pump relay
Mass air sensor
Fuel filter (major PITA)
Engine coolant sensor ( mild PITA)

Cleaned Throttle Body of a 1/4 inch of scum build-up.
Changed associated vaccum and coolant hoses

Changed ECU unit ... and it cleared the hesitation and stumble at 1700 rpm ...

Plan to crack the old ECU and check out the capacitors ...there is a thread on the forums about the ones that can be replaced ...
Thanks for the help and hope this helps someone else

frank

atropine

Followup:

Car seems to be running fine. I have put on about 250 miles since replacing the spark plug. No hesitation at idle or on acceleration. However, I did get a check engine light on for about 15 minutes this morning after first starting it up. Nothing else the rest of the day. Checked the codes tonight, and got a 13. Not sure why. Fuel mileage averaged 20mpg running on the freeway at 80-90mph and just a little bit of in-town driving. Will continue to watch it.

deanshark

Is it possible that code 13 was stored from before or did you clear the codes when you were done? Also, did you ever change that cam sensor you were thinking of? Seeing how at 1313 ohms it's almost out of spec, it could be giving you an intermitent code 13. I would clear the codes and see if it comes up again before changing anything. Is that fuel mileage better now then before you changed the ECT?

atropine

yes, i cleared the codes after doing the spark plug so it is definitely not carried over. i never changed out the cam sensor (it looks like the only place to get the left cam sensor is the dealer for about $175). my mpg has improved a bit since changing the ect sensor and cleaning the throttle body. thx for the input; i will consider changing the cam sensor.

deanshark

Wow $175, that's too much. Check rockauto.com I just looked and they have Beck/Arnley left cam sensor for $88. That's where I usually get my parts from, Quick shipping. I'm not saying the cam sensor is deffinately your problem but it might be.

atropine

thx deanshark, will check it out.

radiohound

Attropine: from what I learned from the dealer, the cam sensor helps fire the engine, that's all in the early engine ... if it is starting and running, its not the cam sensor. In my case they replaced three of them before deciding the wiring was screwed .. and did a work around. I still have my check engine light on but the car works fine ..

I know, its always something ...

TrAPsTaR87

Check Throttle position sensor