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Timing question

1K views 7 replies 3 participants last post by  fredk 
#1 ·
Quick run down. 91 camry 3sfe 2wd.

Very low on power, I found the fuel pump was very weak, and replaced it. Improved the power, but it's still slowwwww. I've triple checekd the timing, and it's right on the money per the marks on the balancer, and cam gear.

The issue is when I set the timing to the proper timing of 10* it's super slow, and when I set it to about the 20* mark or a little more it runs it's best. This leads me to think it's a timing issue. I've always heard you can increase factory power a little by advancing the timing some, but this seems extreme. Any ideas on what could be causing the power to be low, and/or if the timing is off, how would I go about checking it without using the balancer, or cam gear?

Thank you
 
#2 ·
Has it ever had decent power? What changed between then and now? Does it bog and almost stall, or is it just slow? When was the last time the timing belt was replaced? Did you jumper the correct pins on the check connector while you were setting the timing? What other maintenance has been done (or not done?) recently?

-Charlie
 
#4 ·
Thanks for the help. The car has been in my family since day one. It had great power back in the day, but the power has gone south over the years, so it wasn't to noticeable until it got real bad. It’s been really low for a few years, and I'm just now getting around to checking it out. As I mentioned the fuel pump had about 30 psi @ the pump. New pump in car has good FP, and ran better, but still not great.

It's been well taken care of, and the fuel filter was just changed a few weeks ago. I changed the timing belt last year, and it didn't change the power level then. There was some ? about what mark to use on the cam gear, and I pulled it apart and tried the other mark thinking I had the wrong one, but it wouldn't even start set on the other mark, thus telling me it's most likely not the right mark to use. It does still have the org. exhaust system from manifold to muffler. New O2 sensor has been put on. Compression is high I think? It’s around 210 psi on all cly. I thought it should be around 190PSI new?


Could it be the outer ring on the balancer has shifted? If so is there a way to check this?

With the timing at 20* BTDC. It runs smooth just real slow. The funny thing is when I set it to the correct timing it seems to surge. Like if I were giving it gas then not giving it gas. It's not an extreme surge, but it's noticeable. Remember this only at 10* BTDC, the 20 BTDC it does not surge.
 
#5 ·
You are jumpering the pins in the diagnostic box when you check/set the timing, right?

How long has it been since you replace the plugs, wires, cap and rotor? Has the ignition coil ever been replaced?

-Charlie
 
#6 ·
White90DX

I put new plugs, wires, cap, and rotor on about 2 years ago. I pulled the cap, rotor, plugs last weekend. They look fine.

I did put a new dist. in 2 years ago, and the one I got came with a coil, but it wasn't suppose to. I left it in figuring why not. I guess it's very possible that the coil could be bad, just never really crossed my mind until you said something. The old Dist. had the famous o-ring leak with oil soaking the inside of the cap. The old coil was cracked, so I just used the one the dist had in it. The plug wires look good, but I've not gotten around to checking them.

Yes, I jumper the two contacts in the service connector area when doing the timing.

Thanks again everyone. I'll have to pull that shop book out and check the coil.
 
#7 ·
Checked the coil, and wires, the wires are good, but the coil maybe on it's way out. THe ohms range is .13 to .46. I got a reading of .5. Which is most likely closer to .46 as the meter has a tol. of +/- .02.

Timing was advanced, and it runs so much better, thus something is out of align somewhere. I did find that the coolant temp. sensor is broke :lol:. I was tightening the dist. top bolt and hit the coolant temp. sensor and the plug, and connector fell off. Ya it's the org. sensor, and the plastic connector was dry rotted that bad. May not be the may cause of my power issue, but it's not helping.
 
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