3rd & 4th Generation (1992–1996 & 1997–2001)Toyota Camry Discussion for years: 1992-1996 & 1997-2001
Topics of discussion range from fuel economy, safety, modifications, performance all involving America's favorite family car, the Toyota Camry.
I've got a good one for ya. I know this post is kind of a duplicate, but the problem is so unusual, that I thought I'd post it as a different topic.
I've got a running problem with a 94 4cyl Camry, and I've never seen this before.
Wife complains it idles rough, so after some head scratching and diagnosis, it now has a new distributor, plugs and wires, and a known good ignitor.
Its thrown codes, 12 & 13. 13 may have happened when I was testing.
Anyway, I pulled the fuse to clear the codes and went to bed.
This morning , I got up after a sleepless night (the daylight change didn't help) and on a hunch, pulled the upper timing cover to inspect the belt, which I realized was a long shot. It was loose, but not abnormally so. I tensioned it and proceed to recheck the timing, but I got a surprise, something I'd never seen as 20 years as a motorcycle mechanic.
I turned the key to spin the engine, which cranked but would not start, and when I released the key, the tach jumped to 3000 rpm and the distributor made a familiar buzzing noise, like a coil buzzing as it sparked. The tach needle just sat and quivered there reading 3000 rpm.
Did I mention that the engine was not turning?
I shut it off and did it again... same thing
I checked for codes, and got one 11111 11. the factory manual does not list this code, but my chiltons does... bad knock sensor, or bad ECM, but I think that's for a different engine. The factory manual lists 11111 1 as the knock sensor code.
Since the car was obviously sparking and not running, I can only assume the ECM has gone south, since it sends the signal to the ignitor.
I cleared the code and tried again. This time it started, but the engine was flooded. After it cleared, it idled and ran fine.
If anyone has any more info about this phenomenon, I'm all ears, otherwise its off to the salvage yard tomorrow to try to find a good ECM
DTC 52 -- "Open or short in knock sensor circuit with engine speed between 1,200 rpm and 6,000 rpm" . It's a red herring -- the ECU was seeing the 3000 rpm from the tach signal, but not seeing any signal from the knock sensor, so you got a 52.
That's some interesting symptoms. Sounds like the coil / igniter circuit went into oscillations.
How sure of you about that igniter? The igniter is the thing with the transistors, so if there was going to be something giving positive feedback and gain, I'd think it would be something arcing over in the igniter. Just a guess, 'tho -- Toyota doesn't publish anything about the internal construction of the igniter, so I don't know enough to make a positive ID.
Maybe a failure in the coil / capacitor can cause this to happen, too. These days, "rebuilt part" frequently doesn't mean "good part". Again, I'm blowing smoke out my ass -- don't know enough about the internals to say for certain.
I really, really doubt the problem is with the ECU
Not sure what factory manual you're looking in...DTC 52 is right there in mine (from www.camrystuff.com, Generation 3, section EG1 - 5S-FE)
Not sure what factory manual you're looking in...DTC 52 is right there in mine (from www.camrystuff.com, Generation 3, section EG1 - 5S-FE)
Ya, i just figured that out. there IS a code 52, but they have it listed in blinks as 11111 1 (51). Must be a misprint.
Its important to note that none of the stuff I did to it changed the way the car behaves.
It has at least 4 modes of operation. all of them random, but occurring more frequently when cold/cool (60F weather)
Normal,
high idle, rough running (timing and tach jump around a lot
hard to start, floods (maybe)low idle rough running, timing and tach jump, but not as bad
won't start and maybe I get this weird continuous state of fire in the distributor.
The ECU is the part that tells the ignitor when to fire, it reads various sensors and coils and makes that determination. If the timing is jumping all over the place and the distributor drive train is mechanically sound, I can still see it being a pickup coil, but sparking continuously while the engine is not spinning? Just about gotta be ECU?
I've got 2 ignitors, they both do the same thing. The one I'm using now was working when I took it of this car 5 years ago when I was tracing a bad coil. The one that was on the car when this first started is out of a salvage yard, When I installed it 5 years ago and it wasn't the problem, I just left it there.
Last edited by Michael503; 03-14-2010 at 04:36 PM.
Before you replace your ECU, remove the access panel from under the passenger side dash and glove box assembly. Grab your wifes hairdryer and one of your extension cords and run it out to the car. When it freaks out again, leave it running and warm the ECU with the hairdryer. As the ECU electronics warm up, if it is the problem, it should change the way the engine is running. Then you will know for sure. I new a guy who had to warm his ECU every morning in his Mazda in order to get it running. As long as the car stayed warm, the ECU was fine until the next morning.
ECU's just aren't that failure-prone -- they're in a relatively protected environment compared to the engine electronics. I know it seems like you're running out of options, but I usually bet against ECU failure.
Still feels like something in the dizzy, igniter, or associated cabling area. I could see how a flaky condenser (or wiring to it) could cause an awful lot of the symptoms you're seeing.
My bet is a bad ground somewhere. Check all thr grounds in the engine bay, there arent too many and if one is really loose or is not making a good connection thatl do it.
__________________
Quote:
Originally Posted by Tony the Tiger
I mod my Camry because I am too cheap to go out and buy a real sports car
1992 Camry XLE v6: p&p + 3angle, CAI, y pipe, K-Sport coilovers, 5-speed swap
1996 Eagle Talon TSI AWD: IPT 3700 restall, DSMlink v3, HKS exhaust, ETS street fmic kit
Well, I installed the used ECU and BAM! problem solved, I've started the car about a dozen times, warmed it up drove it around, etc. Runs flawlessly! I'm 99% sure this part fixed it, but I will post back if it acts up again.
While I was in car mode, I replaced the timing belt, front oil seals and valve cover gasket. I also sprayed silicone oil on the suspension bushings and wiped the door gaskets with silicone. Now not only does it run well again, it doesn't creak either!
Along the way, I fell in love with the car again... I may have it painted
ECU's just aren't that failure-prone -- they're in a relatively protected environment compared to the engine electronics. I know it seems like you're running out of options, but I usually bet against ECU failure.
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I agree, but one of the things learned as a bike mechanic was that just because a vehicle has a history of a certain part failing, doesn't necessarily mean that part is bad. I've seen all sorts of wierd stuff over the years, and as a previous poster said, a bad ground will drive you nuts and makes electrics do weird stuff.
Unfortunately, you can't test electronic modules, they have to be tested by replacement or process of elimination. Fortunately, My local yard only wanted 50 clams for the box, and it has a DOA warranty.
Last edited by Michael503; 03-15-2010 at 07:01 PM.
Well, I installed the used ECU and BAM! problem solved, I've started the car about a dozen times, warmed it up drove it around, etc. Runs flawlessly! I'm 99% sure this part fixed it, but I will post back if it acts up again.
I should add that I took the liberty of examining my ECM and found that the big capacitor right in the middle of the board took a crap. It wasn't that obvious at first, but it leaked onto the main board. I may replace it just to see if its still good.
I also sprayed silicone oil on the suspension bushings and wiped the door gaskets with silicone. Now not only does it run well again, it doesn't creak either!
Along the way, I fell in love with the car again... I may have it painted
Excellent find!
Be sure to tell the paint boys you sprayed it with silicone - they'll take extra time cleaning it off so it doesn't become a PITA! Silicone and body work just don't mix. THink oil and water!
So the ECU isn't pumped full of potting material (resin) and you can get to the PCBA? Find a good cap of equal or better value and toss it in. Might need soap and water to get the old cap juice off, then alcohol to dry it. . .
go to salvage yard, stop at walmart, stop at Oreillys for belt and gasket, get home by 11:30.
take a break, install ECM... pray, start car several times. smile and sigh, clean out the shop, move tools around and drive car into shop, where there's air and electric light. 12:30
remove valve cover and fill with Dawn power dissolver (walmart), remove timing belt and inspect everything in that area, go to Advance auto for seals that I forgot to get. Clean oily mess, install seals, belt and timing covers. 4:00
Put VC in truck and head for a carwash to pressure wash the cover and baffle, return home, blow cover out with compressed air, install gasket and tube seals and then VC. Warm car up and recheck timing, 2 deg advanced (12 deg total), so I leave it alone ... 5:30
Drive around with the wife a bit, go at the rubbers w silicone and drive around some more. 6:00
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tach reading 3K, engine not turning
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