No check engine light with sensors unplugged - Toyota Nation Forum : Toyota Car and Truck Forums

DailyDriveCamry · 06-01-2007, 10:15 AM

I've been trying to fix my 94 5sfe Auto for the last few months and haven't had much luck. The car will now finally start, but will not run or idle without holding the gas down 1/3 or so. Letting off the gas causes an immediate stall every time. I've replaced a few things to get it this far:

+ New Distributor Cap
+ New Plug wires
+ New Spark Plugs
+ New Ignition Coil
+ Spliced in a new Hall effect sensor in the distributor (old one was cracked)
+ New Coolant Temperature Sensor
+ Idle Air Control Valve was replaced about 2 years ago

I noticed recently that while the check engine light does come on at pre-ignition, once the car is started and running it does NOT come on.

So I disconnected the precat O2 sensor and the EGR sensor to try and force the check engine light on. Nothing. Now if it's not throwing any codes with two sensors unplugged, that indicates a problem with the ECM right? I checked all the fuses and they all looked fine.

I don't have a scanner, can't afford to buy one, and can't drive the car to take it to Autozone or somewhere to have it scanned.

Any ideas?

A friend of mine says the car shouldn't start or run with a failed ECM since it's fuel injected...

Venom_5 · 06-01-2007, 10:19 AM

the throttle cable hasnt been adjusted, correct?

***ASG14*** · 06-01-2007, 10:45 AM

It takes a while for the CEL to come on with a bad EGR/O2 sensor, I know. I have no ERG and it takes a couple hundred miles for the CEL to pop on. And a few miles with a bad O2 sensor.

Luckynumber5 · 06-01-2007, 10:50 AM

Try this, I believe your car has a test mode, this is different from diagnostic mode in that test mode will trigger CEL wheres diagnostic mode reads the stored codes. Bridge connectors te2 and e1 while the key is OUT of the ignition, then start the car and get up to at least 10 mph, then pull back in the driveway and you should have some codes stored if anything is wrong at all.

Test mode will trigger a code if any parameter is not met, the reason you get the car moving before reading codes is that it is so sensitive it will trigger a speed sensor code and store it, unless it verifies that the sensor is working for sure.

You may get several misc codes besides the one that points to your stalling problem, just verify everything before jumping to conclusions.

And be sure you have checked over all your vacuum lines

DailyDriveCamry · 06-01-2007, 12:03 PM

Throttle cable not adjusted to my knowledge.

I will try that Luckynumber5 and let you know the results. And actually, I have not checked over all the vacuum lines. are there any particular ones that would cause instant stalling like that?

***ASG14*** · 06-01-2007, 12:22 PM

Check the brake booster line (But that would also make the brake pedal hard). Also, check the intake HOSE itself for any cracks or holes.

DailyDriveCamry · 06-01-2007, 01:02 PM

Might be worth mentioning that the brakes are ridiculously soft and will go all the way to floor with almost no effort. And yes, they were professionally bled out, which didn't seem to help at all.

***ASG14*** · 06-01-2007, 05:24 PM

Quote:

Originally Posted by JJJJJJ

go to wal-mart, they sell a decent scanner.

if you like it, keep it, otherwise return it.

you could always rent one for free possibly from autozone, they just charge you a refundable deposit.

He has a '94. Needs to be done manually.

Quote:

Originally Posted by DailyDriveCamry

Might be worth mentioning that the brakes are ridiculously soft and will go all the way to floor with almost no effort. And yes, they were professionally bled out, which didn't seem to help at all.

Your Brake Master Cyl is likely bad then.

#1: Are you SURE that ALL of the vacume hoses are on correctly?

#2: Are you SURE the EGR valve is ok?

My Old '92 5SFE Camry had an issue with the EGR Valve. The car wouls stall as soon as it went under 2k RPM's, which made it a BITCH to drive, haha. I think the valve stayed open, in turn, putting too much air into the engine stalling it. I forgot for sure though.

DailyDriveCamry · 06-01-2007, 05:59 PM

Brake Master Cylinder is good. Replaced it with a brand new Aiken one last year. A friend thinks the proportioning valve is bad in the brake system. I have a good one from a wrecked car, but it's such a hassle to replace that I haven't done it.

As for #1 and #2, not really. In fact the EGR threw codes for over six months last year and then finally stopped. Not sure why it stopped. I cleaned it once, but that only seemed to help for a few days.

The EGR Vacuum Modulator had some carbon buildup but seemed to still be working when I tried cleaning it last fall. I didn't replace either because of how expensive they are new, and none of the u-pull yards around me seem to ever get a gen3 in, just tons of gen2s.

A friend thinks the proportioning valve is bad in the brake system. I have a good one from a wrecked car, but it's such a hassle to replace that I haven't done it.

And actually the "by-metal vacuum switching valve (Part #9092505068)" (F shaped vacuum connector in water pipe) broke off a couple weeks ago and is open to the air, so that's definitely a problem now but doesn't change the the fact that all this was occurring before it broke off. Friend hot glued it back together for testing and made no difference, but promptly came apart again. I priced it from Toyota and they want $66 for that dang piece of plastic. Wish I could find one in the yard.

DailyDriveCamry · 06-22-2007, 02:11 PM

Replaced the BVSV with one from junkyard gen 2 as there seems to be no difference.

Tried the test mode. I think I jumped TE1 and E1 though, the same set to read diagnostic codes. I didn't catch that you said TE2, so I guess I need to try it again. I didn't get any codes at all, stored or otherwise with TE1/E1 and a drive around the block.