I am working on my son’s 1990 Camry (145,000 mi) and I’m completely stumped. It all started when my daughter-in-law called to say that she was stranded. I towed the car to may house and started trying to figure out why it died on her. I have subsequently changed the coil and distributor cap, and timing belt. The compression is good and I’ve checked the resistance on the position sensor coils and they check out fine, also the clearances are good. Here’s the part that has me stumped: I know that the crank/cam timing is set correctly according to the manual but I have to turn the distributor to something like 45-50 degrees btdc for the engine to start (the bolts have to be out to allow the distributor to turn that much). When it starts it runs smooth but with no power and will die fairly quickly. Another interesting clue is that if the distributor is set anywhere close to the correct rotation and I watch the timing light while the car is being cranked the spark is close to tdc. It is as though the timing was off 180 degrees but I don’t see how that could be possible. Could the ignition module cause these symptoms or can anyone suggest something?
I think you found the problem, the distributor is out of time. Is the distributor itself bad, stripped teeth on the gear deep inside? Or, did the motor jump time somewhere internally?
I’d pull the distributor and have a look at it, perhaps even take it to a shop for evaluation if all looks ok to you. Pulling a distributor and replacing it and keeping everything in proper time can be tricky. Consult a shop manual before pulling it.
You are likely off something like the 180 degrees you mentioned. Question is how did that happen? An old distributor can get loose and perhaps the gear moved upwards enough to skip a few teeth. When the motor stopped the gears moved back into place, but out of time. So, the distributor is moving, but if the motor runs for any length of time it will happen again. My guess is a worn out distributor, but still just a guess. Check it out.
You said you replaced the distributor cap, how about the rotor? If the rotor is not down on the shaft completely it might be in the wrong place. This would mess up the timing, it is simple to check out. I’ve never seen a rotor break the “key” that locates it on a distributor shaft, but I guess it could happen.
Thanks for the response.
I have had the distributor out several times. I will go in only one way and fits into the end of the intake cam so I can’t see any way for the distributor timing to be out of sync with the cam. The distributor shaft has an offset tab that fits in a slot in the end of the cam. Also, on this engine the crank position sensor is inside the distributor so the crank position indicator depends on the cam timing being correct. There is a mark on the crank position rotor but I haven’t found any information on what its supposed to line up with. Perhaps it is possible for the position sensor rotors to move inside the distributor?
The ignition rotor is in good condition with a D shaped hole that fits the shaft so it is mechanically bound to the correct position. It has to be pushed way down on the shaft in order to get the cap on so I’ve ruled that out…
I hate troubleshooting by replacing parts.
Second sentence should read “It will go in only…”
You mentioned changing the timing belt. I’d consider double and triple checking the cam timing just to make sure. The way you say the car only starts with the ignition 50 degrees out, but no power, the cam(s) may be off time. It sounds like it is off by a couple of cogs.
The timing light test I mentioned in my original post indicates that the crank to cam timing is right. With the bolts in the distributor and the distributor set to very close to its original position the timing light indicates that the spark is very near tdc. This would not be the case if the cam timing was off I don’t think. I have set the belt timing several times and would stake my life on the fact that it is at the very most 1 notch off. One notch should let it start I would think. I am very confident that the mechanical timings are correct. What I don’t know is if the crank or cam position sensor can move on the distributor shaft or if the ignition module could cause the symptoms I’m seeing. I am not a novice and have changed several timing belts on a variety of cars but I have never seen this behavior before.
@kelley1954 I understand that the car didn’t start . . . but why did you remove the distributor in the first place?
What engine do you have?
When you install a distributor, you set #1TDC on the compression stroke
Is it possible you set the companion cylinder to TDC on the compression stroke?
I removed the distributor to change the coil. I jumped to the conclusion that the coil was bad based on symptoms but unfortunately that was not the case.
The compression stroke is determined by the relationship between the cam and crank. If the crank is TDC and you set the cam to its timing mark that makes #1 TDC at the top of its compression stroke. This engine will not let you install the distributor incorrectly.
My next strategy is to move the timing one notch at a time (rather tedious) and see if it gets its act together. The way the cam timing is set makes it very difficult to tell for sure that it is right. You have to see through a small hole in the cam gear to the mark on the head and the fender is in the way.
@hit that mark with white out or a highlighter.
When I last did a timing belt on a 1996 Camry with the 5S-FE engine, I was fighting that mark, because I was never really sure if everything was lined up. After painting the mark, it was very obvious, even through that little hole in the sprocket.
Thank you to those who tried to help. It now runs and, I have to say, I don’t like crow. Sure enough, after I move the timing two notches on the cam sprocket it started and ran. I feel so foolish
Even now, with it working, it does not look like the marks line up but the proof is in the pudding.
I’m glad you found the issue.
@kelley1954 check your ignition with the timing light.
If the timing belt is positioned such that camshaft and crankshaft TDC marks don’t align per spec, then I don’t think you are done yet. Something remains askew. The fact that is runs doesn’t mean it is running correctly. It may overheat, rough idle, poor mpg, poor acceleration, not pass emissions tests, turn on the CEL, etc. Running it like this may in fact damage the engine.
I have an early 90’s Corolla, 4AFE engine, which I think is somewhat similar to yours. Yours is fuel injected, right? Dual overhead cams, but the timing belt only goes over one cam pulley? You can set the timing by turning the distributor, but there’s a sensor that senses the position of the distributor shaft that triggers the spark plug firing. And the ignition coil(s) are part of that ass’y. Right?
When you replaced the timing belt, did you check the cam/crank timing marks as it was aligned on the old one before doing the replacement? My theory is that your timing belt may have slipped for some reason, which is what caused the engine to stop. If the timing belt is past its wear limit, it can slip on rapid acceleration or decel. The rotational inertia can cause it to slip. Either that or like said above, the distributor slipped. Was the distributor loose when you removed it? What motivated you to replace the timing belt?
re: “I watch the timing light while the car is being cranked the spark is close to tdc. It is as though the timing was off 180 degrees but I don’t see how that could be possible.”
I don’t understand what you mean by this. When it is running correctly, I’d expect the timing light to show the #1 cylinder to be near the TDC. Actually a few degrees before. Or do you mean it is at TDC, but TDC on the exhaust stroke instead of on the compression stroke, and it doesn’t run in that position? That would be an idication the distributor has slipped in relaitonship to the crankshaft, or the sensor and/or associated electronics inside the distributor has failed.
I guess what I’d do in this situation is get the Make/Model/Year’s Shop Manual for the car and look up the alignment procedure for both the distributor and the timing belt, and make sure both are aligned per spec. If you don’t have the shop manual, you can find that info at your local public library I expect, either in the Motor manuals they have, which are sort of an abbreviated shop manual, or check with the librarian, they may have All Data computer data base service for auto repair procedures, which is easier to use.
Best of luck.