[Tricky]

I recently bought a 1990 Escort LX. When I took it for the test drive it ran good at first but after about 1 minute of driving it began to backfire and lose power. Acceleration response was sporadic. The seller said it had never done that before. I got a
deal on the car because of this issue. When I came back with my tools, the car would sputter when the starter was engaged but as soon as I stop turning the key it would die. I posted a question about this problem and got a few suggestions that it was most likely the ignition control module. I replaced the ignition control module and the car started up and idled. When I took it for a drive it began to misfire and backfire again. The exhaust smells very rich and smoking. Now I'm not sure if it is a ignition issue or a fuel issue. I tried adjusting the timing at the distributor and it doesn't seem to help. Any advice would be greatly appreciated.
Thanks

 

[Hemi Buff]

View attachment 55386
I recently bought a 1990 Escort LX. When I took it for the test drive it ran good at first but after about 1 minute of driving it began to backfire and lose power. Acceleration response was sporadic. The seller said it had never done that before. I got a
deal on the car because of this issue. When I came back with my tools, the car would sputter when the starter was engaged but as soon as I stop turning the key it would die. I posted a question about this problem and got a few suggestions that it was most likely the ignition control module. I replaced the ignition control module and the car started up and idled. When I took it for a drive it began to misfire and backfire again. The exhaust smells very rich and smoking. Now I'm not sure if it is a ignition issue or a fuel issue. I tried adjusting the timing at the distributor and it doesn't seem to help. Any advice would be greatly appreciated.
Thanks

 

[Hemi Buff]

I read about your problem, there is a small plastic black block on top of where the air exits the air-cleaner housing with 2 phillips head screws, the words " AIR FLOW are imprented on top with the arrow pointing towards the engine. By removing the screws it will lift right off. On the bottom side are 2 pair of tiny pins, between each pair there should be what looks like tiny springs. These are probably broken if they are not attached to only the 2 pins each. If you can absolutely be shure they are inplace and not hanging down , then it can be the plastic screw in " Air Temp Moniter ". This is located near the entrance side cover of the air filter assembly. Remove the 2 wire electrical clip and unscrew it out of the air filter cover. Using an OHM Meter ( red lead to Volt-ohm & black lead to common ) you can test this moniter by carefully touching the 2 male terminals where the electrical clip connection goes. If you get Zero readng on the amp probe, its bad, if you get continuity the meter will display a reading like 159 or 210, or even 108. An OHM meter Cannot Shock You ! Most auto parts can order these temp. sending units. Good Luck

 

[Shorty]

Try wiggling the throttle position sensor connector while the engine is running... see if the engine hick-ups as you wiggle. I had the sensor and connector go bad on mine and it caused a random problem similar to what you've described.
Congrats on getting the car for a deal!

 

[Tricky]

I read about your problem, there is a small plastic black block on top of where the air exits the air-cleaner housing with 2 phillips head screws, the words " AIR FLOW are imprented on top with the arrow pointing towards the engine. By removing the screws it will lift right off. On the bottom side are 2 pair of tiny pins, between each pair there should be what looks like tiny springs. These are probably broken if they are not attached to only the 2 pins each. If you can absolutely be shure they are inplace and not hanging down , then it can be the plastic screw in " Air Temp Moniter ". This is located near the entrance side cover of the air filter assembly. Remove the 2 wire electrical clip and unscrew it out of the air filter cover. Using an OHM Meter ( red lead to Volt-ohm & black lead to common ) you can test this moniter by carefully touching the 2 male terminals where the electrical clip connection goes. If you get Zero readng on the amp probe, its bad, if you get continuity the meter will display a reading like 159 or 210, or even 108. An OHM meter Cannot Shock You ! Most auto parts can order these temp. sending units. Good Luck

Thanks for the advice. I will try that.

 

[Tricky]

Try wiggling the throttle position sensor connector while the engine is running... see if the engine hick-ups as you wiggle. I had the sensor and connector go bad on mine and it caused a random problem similar to what you've described.
Congrats on getting the car for a deal!

Thanks. I will try that. I hope it's something simple like that.

 

[marclar]

check for spark and fuel pressure. these cars are famous for bad tfi modules and failed regulators

 

[Tricky]

I read about your problem, there is a small plastic black block on top of where the air exits the air-cleaner housing with 2 phillips head screws, the words " AIR FLOW are imprented on top with the arrow pointing towards the engine. By removing the screws it will lift right off. On the bottom side are 2 pair of tiny pins, between each pair there should be what looks like tiny springs. These are probably broken if they are not attached to only the 2 pins each. If you can absolutely be shure they are inplace and not hanging down , then it can be the plastic screw in " Air Temp Moniter ". This is located near the entrance side cover of the air filter assembly. Remove the 2 wire electrical clip and unscrew it out of the air filter cover. Using an OHM Meter ( red lead to Volt-ohm & black lead to common ) you can test this moniter by carefully touching the 2 male terminals where the electrical clip connection goes. If you get Zero readng on the amp probe, its bad, if you get continuity the meter will display a reading like 159 or 210, or even 108. An OHM meter Cannot Shock You ! Most auto parts can order these temp. sending units. Good Luck

Thanks. I'm not sure where the box is. Do you mean this thing?

 

[Hemi Buff]

Thanks. I'm not sure where the box is. Do you mean this thing? View attachment 55403

 

[Hemi Buff]

Sorry, I can't see what your talking about at all..Does that engine run on a carburetor ?

 

[Tricky]

Sorry, I can't see what your talking about at all..Does that engine run on a carburetor ?

It's a throttle body injection system.

 

[Hemi Buff]

Ok, but your picture didn't show the sensor on the air cleaner cover, that was what I originally tried to bring to your attention, if I could have seen it I would have told you if it was what I was talking about.

 

[marclar]

the part in the picture is the throttle position sensor.

 

[Hemi Buff]

Lol, thats not the same thing as the air filter canister with the removable top, as I described in my original reply to your problem. I cant remember if your make and model Escort has temp. sensors mounted on that filter lid. If it doesn't they may be located some place else, or even non-existent .

 

[UnexplodedCow]

A month later - inquiring minds wonder.....was it solved?

 

[Hemi Buff]

Check the distributer cap, it my be old with tiny cracks causing the spark to short our to the ignition wire next to it, or even dry-rotted ignition wires going to the spark plugs. Get someone to turn over the engine while the shop lites are off, and you'll be able to see the sparks jumping from wire to wire a lot easier.

 

[Tricky]

A month later - inquiring minds wonder.....was it solved?

Not yet. Been busy. Was going to try replacing the ECU but it's difficult to access. I have to get the part number before I know if I can find a replacement.

 

[UnexplodedCow]

Swapping ECUs is not hard. They're located under the dash on the driver's side. Takes about 2 minutes to get it out, mostly due to wire loom stiffness. 10mm (or 8mm) bolt that holds the harness connector on. Unbolt, slide the connector apart, and wiggle the ECU out of its shelf.

As for what replacement, any year CFI should work, and I've used automatic ECUs in manual cars (the upshift light even works).

However, I doubt it's the ECU, and if it is, the culprit would probably be a leaky electrolytic capacitor (which can be cleaned/fixed very cheaply if you or a friend have the skills). My guess is the injector is stuck open a bit, perhaps adding too much fuel, the TPS may be faulty. Check the distributor for wobble or egg-shaped wear on the rotor button - that can cause intermittent spark strength/timing, which will cause backfire. Most importantly, check the mechanical timing. If the belt was loose or worn, and jumped 1 or two teeth, the engine would start running very oddly, with sporadic response, acting like it was missing a cylinder, very low power. The engine would still run, but pretty badly, and very often will also backfire right out the intake on a CFI. Each tooth represents 4 degrees of cam timing, so it can cause a pretty large effect, very quickly if the jump is sudden.

Just some late-night thoughts.....

 

[Tricky]

Thanks. I'll check those things. I suspect that it's not the distributor cap because the car ran fine when I first test drove it. It wasn't until it ran for a few minutes before it ran rough. Now it's running rough all the time and won't even stay running. I know it must be something simple. It is so frustrating. When I get more time I'm going to tackle it again.