1987 Camry 3SFE - Fouling plugs, won't rev, spits and sputters

[ss-blazer]

Hey guys, I've been a long time reader of the forum as I have a 1987 camry DLX with a 3SFE engine and have usually been able to find an answer to my questions just by using the search function. However, here is my issue:

I was driving to work last week and out of no where the car began to run poorly. At a light it would idle fine but the very moment i touched the gas pedal it would spit and sputter till about 3k rpm then it would clear up and accelerate. Well the engine light pointed to the O2 sensor. I replaced that, still running poorly. Next I replaced the coil because it was all cracked and had oil leaking out of it. Still running poorly. I replaced the timing belt, still running poorly. Replaced plugs (the old ones were completely BLACK), still running poorly. New fuel filter and distributor rotor, still running poorly. I'm out of ideas guys. From my limited mechanical knowledge it appears the plugs are being fouled the moment I hit the gas pedal. I had a timing light on the balancer and noticed the timing goes from 10 degrees to 0 the moment I touch the throttle. I'm just wondering if maybe the distributor is taking a dump or if its a TPS issue? Any advice would be greatly appreciated.

Thanks!

[white90dx]

You are going to have to figure out whether you are getting too much fuel or not enough spark...

You have already done the right things (replacing coil, spark plugs, etc.) for the spark side of things.

I have a hunch that there is a problem with your TPS or AFM at this point, it might be worth it to bench test those parts if you can.

Had you done anything under the hood before this started happening (in the week or two before...)?

-Charlie

[ss-blazer]

Originally Posted by white90dx

You are going to have to figure out whether you are getting too much fuel or not enough spark...

You have already done the right things (replacing coil, spark plugs, etc.) for the spark side of things.

I have a hunch that there is a problem with your TPS or AFM at this point, it might be worth it to bench test those parts if you can.

Had you done anything under the hood before this started happening (in the week or two before...)?

-Charlie

The only thing I did was change the oil. I did it about 3 days before this happened. What is the AFM?

[white90dx]

AFM = Air Flow Meter. It is part of the top lid of the air box and has a flapper door that opens with airflow. The plug on it is confusing to take off - don't ever loosen the screws. You have to pop off a small metal c-clip to remove the plug. If the screws are removed and you pull on the harness, you can damage internal components.

Check for air leaks in the intake tube and vacuum leaks.

I also noticed you put a timing light on the engine... make sure that when you are checking the timing that you jumper the T and E1 connections in the diagnostic plug in the engine bay (instructions are on the emissions sticker under the hood). If you don't, the timing will jump around.

Have you replaced the spark plug wires? Also, OEM ignition components are by far the best for this car. Make sure you are using the standard (non platinum, etc.) NGK or Denso plugs. They are very cheap and work well on this engine.

-Charlie

[ss-blazer]

Originally Posted by white90dx

AFM = Air Flow Meter. It is part of the top lid of the air box and has a flapper door that opens with airflow. The plug on it is confusing to take off - don't ever loosen the screws. You have to pop off a small metal c-clip to remove the plug. If the screws are removed and you pull on the harness, you can damage internal components.

Check for air leaks in the intake tube and vacuum leaks.

I also noticed you put a timing light on the engine... make sure that when you are checking the timing that you jumper the T and E1 connections in the diagnostic plug in the engine bay (instructions are on the emissions sticker under the hood). If you don't, the timing will jump around.

Have you replaced the spark plug wires? Also, OEM ignition components are by far the best for this car. Make sure you are using the standard (non platinum, etc.) NGK or Denso plugs. They are very cheap and work well on this engine.

-Charlie

Ah okay yeah the air flow meter. Gotcha. Whats weird is I can put the pedal down to the floor with it in Park. It will spit and sputter and pop back through the air box.

I've listened around the intake tube to see if I could hear any type of air suction but I haven't been able to detect any.

I did not jumper the two terminals while checking the timing. I may do that tonight just to see where it is. The only things I haven't replaced are the distributor, distributor cap/wires, tps, afm, and cat converter. I always use NGK plugs. Best there is in my opinion.

[midnightrunner]

You said you replaced the coil and that there was oil? If that is the coil inside the distributor cap, have you changed the distributor o-ring. If you take off the distributor cap and there is more oil, then that probably is your problem. 5 dollars for parts and you will be happy for years.

Good luck

[holmesnmanny]

The intake tube has to be completely leak free or the car will either run like crap or will not start at all or will "pop" when trying to start it. If anything, pick up another intake tube from the junkyard. This is what I did and it worked like a charm when I sprung a leak before.

[ss-blazer]

Originally Posted by midnightrunner

You said you replaced the coil and that there was oil? If that is the coil inside the distributor cap, have you changed the distributor o-ring. If you take off the distributor cap and there is more oil, then that probably is your problem. 5 dollars for parts and you will be happy for years.

Good luck

There was oil. I cleaned the cap out real good. I pulled it back off last night and there is no "new" oil inside the cap. The car won't start now. I think the plugs are completely fouled.

[ss-blazer]

Originally Posted by holmesnmanny

The intake tube has to be completely leak free or the car will either run like crap or will not start at all or will "pop" when trying to start it. If anything, pick up another intake tube from the junkyard. This is what I did and it worked like a charm when I sprung a leak before.

I will recheck the intake tube and make sure its not leaking. I may start replacing vacuum lines as well. I noticed the vacuum line from the valve cover to the throttle body is in sad shape. I don't think thats my problem but I'm sure its not helping.

I think my next move is to either replace the distributor or replace the fuel pressure regulator. After that, I guess I'll pull the catalytic converter off and check that off the list of possible reasons.

[shippo]

white90 is onto something i had a defective AFM and this is what my car did, it must be this! its where the sensor plugs into attatched to the intake

[ss-blazer]

Well the car won't even start now. I thought it was the fouled plugs so I put a new set in there and it didn't make a difference. I went to the junkyard and found a spare distributor and AFM. I tried both of those with no change in the condition of the car. Ugh. I'm running out of ideas. LOL!

[dem2757]

Poor spark? (bad battery/alternator)
Bad gas
Igniter burnt out
Grounding problem
Clogged egr?
Vacuum leaks
Internal engine problems (hopefully none...)

[Doctor J]

These are general suggestions.
If your old plugs were black the car was running rich.
Now make sure you have a spark
if you have nice spark check for leaking cold start injector and fuel pressure regulator (via the vacuum tube)
If plugs were covered by ash deposits (like cigaret butts0 the engine is burning oil and may need hotter plugs

[deucer]

Let me chime in and add some comments regarding this post. I have looked at this specific vehicle on behalf of "ss-blazer" and have come across something what I think is strange. Please correct me if I'm wrong. Fuel distribution: Started off with fouled (black plugs). Further analysis determined insufficient fuel distribution after distributor and coil replacement. Initial troubleshooting indicated no fuel flow with key in "on" position. Further troubleshooting with volt meter suggested fuel pump dead. Dropped tank and tested fuel pump and it is good. Hooked back up external to tank and hit key to "on" but would not energize Pump until I went to the start position. My logic says when the key goes to the "on" position, fuel pump should energize as if the engine was running, Yes or No? The pump only energizes when you go to start... How can it continue running after the engine starts? Alternator cannot run it independently unless there is another circuit involved. Please correct me if I'm wrong, but this points to potential electrical issue with the fuel pump not energized with key in "on" position. The problem I have is the primitive shop manual does not break down the electrical circuitry from ignition to fuel pump to determine possible problem.
Any help is appreciated and thank you.

deucer

[Doctor J]

the fuel pump on that car and many others with airflow meter is actuated if either one of the conditions are present: 1) the key is in the start position 2) the engine is sucking air in so the airflow meter flap is off its resting point (and fuel pump relay switch is closed)