Check engine

[Motorhead6T5]

I know the simple solution is to check for codes,but I was wondering if anybody else has had the same problem. The check engine light will blink on and off when I drive the car(90lx)during warm up,after it is fully warmed up it won't do it anymore.The car runs great but it always does this when I first start to drive it the first time every day. Putting on a cold air intake seemed to amplify the problem,but it drives fine,just started to blink more and stay on longer.Just wondering if this is a common problem with a normal fix,so I don't have to purchase a code reader.

 

[HISSIN50]

all you have to purchase is a paperclip.

the electronics make it harder to track down the cause of stuff, but their self diagnostics help to make up for it, unless you dont use them.

if no one has some ideas for you, i would pull some codes and report back.

good luck.

 

[jrichker]

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

 

[alanw6]

motorhead, I get the occasional brief check engine light flash while warming up for the first few minutes. It appears to have no real pattern, and isn't an everyday occurance.

I'm keeping my eyes on this thread...

 

[5.0 Nostalgia]

I am going to guess it has something to do with the EGR or another emissions problem. My 91 GT does the same thing. However, this car does it for a good amount of time after warm up. Because it blinks and does not stay on, I would say a sensor such as the EGR sensor is malfunctioning.

 

[jrichker]

Don't just guess, or throw parts at it in hope of fixing it. Dump the codes, after all, how expensive is a paper clip?

 

[MusPuppis]

J is right. It only takes 10 minutes of your day. It kinda sounds intimidating when you read about how to do it but when you actually buckle down and pull them its easy and can save you a fortune.

Either way, even if your car runs fine I'd still track down and fix the problem casuing the engine light to come on and off, whatever it is may take a while to fully fail but when it does it could cause some serious problems down the road. Im a big fan of having EVERYTHING working regardless of its effect =]

 

[5.0 Nostalgia]

I wasn't suggesting he guess and buy the parts based on my experience. In my case, I extracted the codes with my scanner to conclude why my check engine light was coming on. And I suggest he do the same. I would just like to know his results to see if they are the same.

 

[Motorhead6T5]

Thanks for the info guys,its pooring down rain yesterday and today.As soon as it lets up I will attempt to pull the codes and keep you posted.Are the $30 dollar ones at auto stores decent? I'm thinking it might be good to have,does it make life easier or should I just use the paper clip method?

 

[jrichker]

It's all in what you are confortable with. None of the $30 scanners have a numerical display to post the codes. They all just flash an LED at you. Follow the link to Acton in my previous post and you can see first hand what you are getting for $30.

For $30 I personally would rather do my homework and use the check engine light or a test lamp.

 

[Motorhead6T5]

It's all in what you are confortable with. None of the $30 scanners have a numerical display to post the codes. They all just flash an LED at you. Follow the link to Acton in my previous post and you can see first hand what you are getting for $30.

For $30 I personally would rather do my homework and use the check engine light or a test lamp.

I just bought one with a numerical digital readout for $35 at Kragen.It comes with a book of codes too.It flat out tells the the code,no counting blinks. I figure if I'm at the track and it throws a code it will be quicker and easier to figure out whats up.Hopfully it won't rain tommorow.

 

[jrichker]

I just bought one with a numerical digital readout for $35 at Kragen.It comes with a book of codes too.It flat out tells the the code,no counting blinks. I figure if I'm at the track and it throws a code it will be quicker and easier to figure out whats up. Hopfully it won't rain tommorow.

Wow - For once I am glad to be wrong. Please post the name, model number, and company name & website address. I would like to add this to my tech notes for future use.

 

[MusPuppis]

J,

I did a search and came up with This I think thats what hes talking about. Not a bad deal at all really. I'll still be counting flashes cause im a cheap bastard though, hehe.

EDIT: Its also on Advanced's website which appears to be almost identicle to Kragens.. So I guess their owned by the same folks.. Anyway, Equus 3145 is the model number.

 

[Motorhead6T5]

Yeah the package says INNOVO EQUUS #3145. If I'm not mistaken these things used to be $100+ back when I had my other fox.

 

[Motorhead6T5]

Ok I ran the codes,and I got a 31(c)- EVP or PFE circuit below minimum voltage.

Does anybody know what that means lol? Please help I'm an idiot when it comes to computer controlled cars.

EVP-EGR Valve Position sensor or its circuit.
PFE-Pressure Feadback EGR sensor or its circuit.

 

[jrichker]

CODE: 31 (KOEO) - EVP circuit below minimum voltage. Vref (5 volt reference voltage supplied by the computer) missing or broken wire or bad connection in circuit. Use a DVM to check for 5 volts on the orange/white wire. If it is missing, look for +5 volts at the orange/white wire on the TPS or MAP sensor located on the firewall near the center of the car. Use the black/white wire for the ground for the DVM. With the sensor removed from the EGR and still connected, press the plunger and watch the voltage change on the brown/lt green wire.
Pull the passenger side kick panel and measure the voltage at the computer. You will need to remove the plastic cover over the wires and probe them from the backside. A safety pin may prove very useful for this task. Use pin 27, EVR input (brown/lt green wire) and pin 46, signal ground (black/white wire) to measure the voltage. The orange/white wire is Vref and should always be 5 volts -/+ .25 volt. Be sure to measure Vref at the EGR sensor to rule out any broken wires or bad connections.

 

[Motorhead6T5]

Thanks for the info :worship: ,so if I'm getting 5 volts is the sensor bad?

 

[jrichker]

Follow all the directions in the test path to make sure you don't spend the $21-$28 for a sensor if you don't need to. It will take less than an hour to do it all.

Saving $28 for an hour's effort is a good return in most anyone's book, unless you are Bill Gates or someone like that...