1997 Corolla won't start. Out of ideas. Also why I no longer trust Big Al

toyota
corolla

#1

Friday of last week my wife’s Corolla refused to start. It cranked strongly but refused to catch. Fearing the worst my mechanic father-in-law assumed the timing belt had gone and we spent the weekend replacing that. The tensioner bearing had seized leaving the timing belt glazed but intact and, as far as we could tell, the timing was still correct. We replaced the belt and closed her back. Tired turning it over, nothing. Father-in-law noticed he didn’t hear the fuel pump turn on when the key was placed in the ON position so he replaced that and the fuel filter. Turns out that the fuel pump only comes on when it’s cranking? Who knew? We didn’t. So that’s been replaced.

At this point we have it towed to the shop where my father-in-law works(After this point all my information is second hand). We were going to let Big Al, their resident diagnostician, hook up his magic boxes and tell us what’s wrong. Big Al suggests it’s the distributor so that’s changed but it still doesn’t run. Big Al suggests that we set the timing incorrectly. That is torn apart again and, remember this is second hand information, “it was right but it was wrong”. Whatever, they get it back together and it cranks and runs! Hooray!..but not so fast.

Next morning father-in-law arrives at work and gets bubkis. Cranks, sounds like it wants to start but won’t. Somehow Big Al determines it’s the PCM and that the car is getting “too much of a fuel pulse from the injectors” I ask if they are able to pull any codes from the computer and I’m told that they can’t get any codes from ODBII scanner because it can’t communicate with the car’s computer. Also it’s found that the catalytic converter is completely shot.

That brings me to now. I can buy a used PCM for 55 bucks but I have little confidence that it will work. Can anyone in the Car Talk community offer some angle on this that hasn’t been explored? If i left out any relevant information please ask. Any advice would be appreciated.

Thanks
Eric


#2

Ready, FIRE!, aim.

Looks like they proceded to the “fix stuff” stage, without adequately doing the “figure out what’s broken” stage.

If a car fails to start, it is because there is a breakdown in one of three systems: fuel, air, or spark. So far, the timing belt was done (air); then the fuel pump (fuel); then timing adjustment (spark); then PCM problems w/ furl pulse (back to fuel).

This tells me they’re guessing.

If it were my car, I’d do a compression test. If that checks, I’d perhaps see if it would run on ether. Based on what I found there, I might need to break out the timing light. (Oh, and read the plugs while I did the compression test.)


#3

Wow. What you need is a mechanic who actually knows how to systematically diagnose a problem. Unfortunately your FIL and Big Al don’t seem to fit that description, and they will continue to throw parts at it until something works, leaving you poorer and frustrated.

Your real dilemma is how to get the car away from FIL and Big Al without hurting any feelings. You could take it to a dealer, where their trained (hopefully) diagnosticians will find the actual problem, but it will be expensive. On the other hand, throwing random parts at it and wasting a lot of your time has a cost, too.


#4

By the way, it could be something as simple as a bad crank angle sensor.


#5

Thanks MeanJoe

Admittedly this was done in a rush and now we’re paying for it.

Compression test was done. One cylinder was a little lower the others but the car has 240K on it.


#6

My FIL was likely an excellent mechanic until about 1992. The era of auto techs with laptops has completely passed him by. He’s 65 now and mostly does brake jobs and wheel alignments. I can’t really attest for Big Al.

I’ve thrown ideas like crank sensor and even a coolant temp sensor at them and they have been dismissed, Mostly by big Al. FIL seems sort of defeated by this whole thing, he’s more than willing to bring it elsewhere. At this point, at least as far as I’m concerned, it seems like there must be something obvious that’s being overlooked.

What really stinks about this whole thing is that my wife is set to buy a late model Chevy Malibu in December. A family member’s husband is being stationed to Hawaii and she’ll be buying that. This cursed thing just had until then.

Thanks all.


#7
I'm told that they can't get any codes from ODBII scanner because it can't communicate with the car's computer. Also it's found that the catalytic converter is completely shot.

Back up. What? They can’t get anything from the computer, but it told them the cat is shot? How did it do that, if they can’t get anything from it?

There’s something fishy going on here.


#8

Since your not getting communications from the ECU the first thing to check in that situation, as with a lot of others also, is power to the device. Most likely it isn’t getting power to it. Even if the CEL light does work there could possibly be a power connection problem since there is most likely more than one power connection to it. If that checks out okay then check the data lead connections. If those check out then it is time to think about a replacement ECU.

Things have changed over the years on how engines are controlled but lots of things are still the same also. Just using good logical test methods and some understanding how the newer engine designs work goes a long way in getting to the problem and fixing it.


#9

On my early 90’s Corolla, like yours, the fuel pump only runs when the engine is turning. That’s why the fuel pump relay is called the “Circuit Opening Relay” on Toyotas, or something similar to that. It is from the days when the engine rotation was determined by the points opening and closing. I expect you’ve learned that just because the fuel pump isn’t running, it doesn’t mean there is something wrong with it. A voltage measurement should be made at the pump before making any decisions. The problem is that now, the new pump may be the cause of your problem. Did they put in an OEM pump, or an inexpensive off-shore rebuilt unit? If the latter, that’s something to be suspicious of. It may be that your shop is spot on, but me, I doubt from what you say there is a problem with the ECM (or PCM). Seems very unlikely, since the ECM wasn’t the cause of the initial problem.


#10

Sounds like a lot of guessing has been going on and one wonders how they determined the converter is shot on a non-running car or how they came up with this too much of an injector pulse thing.

Have none of them considered checking every single fuse on the car to make sure that’s not the problem? The EEC system is probably tied in with half a dozen fuses and one blown fuse could kill the entire operation.


#11

@EricD

Has anyone checked that the coil is good?

Until recently, I had a 1995 Corolla 1.8, essentially your car.

One day, it wouldn’t start.

I verified fuel and compression were good.

Then I popped off the distributor cap and checked out the coil. The resistance was fine, but the coil was actually cracked! Once I replaced the coil, the car started right up.

Food for thought


#12

Am i incorrect in assuming that if it were the ECU/PDM that it wouldn’t be an intermittent problem?


#13

You may or may not be correct. If it’s a faulty connection, like a bad solder join, it can absolutely be intermittent. If it’s something like a burned chip or board, then it would not be intermittent.


#14

Another idea. Does Big Al have the Toyota-specific scan tool? If not, you should find a shop that has it. Proper diagnosis is the key here. You need someone experienced with Toyota OBDII diagnostic procedures to assist. Even if you use them only for the diagnosis, then use another shop of the repair work. Replacing parts until it is fixed for a problem like this is unlikely to work; you’ll almost certainly run out of money before you actually solve the problem.


#15

There is a chance that there could be something like an intermittent connection inside the ECU but I think the chances of that happening is pretty slim. An intermittent issue would most likely mean the ECU is okay and something external to it is causing trouble.


#16

We were ready to have the car towed to the local dealership to have it diagnosed and, on a whim, my FIL turned it over and it started. Hooray!..i guess. We canceled the appointment at the dealership because I assume it would be difficult to diagnose a problem that isn’t happening. I have already ordered a used ECU/PDM and we’ll keep that at hand in case…lets face it, when it fails to start again we’ll have something to try.

I’d like to thank everybody for their advice.


#17

Keep us posted.

Don’t be surprised if the new ECU doesn’t fix things. ECU output problems can also be caused by loose/frayed wires.


#18

Thanks shadow. I’m fully expecting more problems between now and December.


#19

I am having this exact same problem. One morning a couple weeks ago my '97 Corolla would not start. Exactly the same thing happened, where it was cranking really strong but did not want to start. Ended up replacing the distributor cap and rotor. Nothing. Decided I could either keep throwing in new parts until I fixed the problem, or take it to a mechanic. I got it towed. They replaced the plugs, plug wires and air filter. It started right up and sounded like new. Apparently “it just needed a tune-up.” Awesome… That night I went to work the night shift, and when I got out in the morning, the same thing happened. Tried to jump it. Failed. Left it there, got a ride home, and came back in the afternoon. Called AAA to tow it, but the AAA guy was able to get it started again. So I took it home and wanted to figure out myself what the problem was before spending any more money getting it “fixed”. Replaced the ignition coil and got the alternator tested, but the problem still exists. The fuel pump sounds like it’s working, and now, like EricD, I’m out of ideas. Are you still having this problem? If not, how did you fix it?


#20

Big Al is practicing “shotgun maintenance” which is rarely effective but always expensive. He’s in over his head and he knows it.