I hope the problems aren't too bad.

First of all, I was cruising on the freeway 4 days ago at about 65-70 in my 91 pickup, and the check engine light pops on, and hasn't turned off. Does anybody have any ideas as to what this could be?

Second- In the few weeks I've had this truck, before the CE light came on permanently, it would come on if I had to slow down suddenly, as in go from 45mph in 4th to 3rd to 2nd gear and 10 mph, because of retarted SoCal drivers. The light would stay on until I got back up to around 25 and was shifting into 3rd. Any ideas?

Since my mom said that I can't get exhaust until I figure this out, and getting this checked will be around $70, would I be able to do it with this, by myself?

 

Yes, you need to pull the code. I dont know if that part from Harbor Freight would work or not. I think Autozone will pull it for free.

 

I hope they will, cause I have an AutoZone about 2 min from me. What do have to do once you have the code?

I'm new to modern-ish vehicles, cause my first car, an 86 Jag, didn't have a check engine light, so I didn't know if anything was wrong with it until it didn't work.

 

Probably not, your truck uses an OBD I system and although it is very similiar to OBD II, it might not be able to read the error. But ya definitly take your truck to any auto part store (Autozone, Kragen's, Chucks, Chief's...whatever) and provided they have the right adaptors and readers, they should be able to pull a code for ya.

 

When the code is pulled, the rep will tell you what it is...come back to this forum and let us know what it is and we can direct you to the right fix, it might just be a simple O2 sensor that needs replacing.

 

Oh, I heard somewhere that it was OBDII. Maybe I'm just on crack.

I'll go to Autozone once my truck warms up, and what do I do once I get the code?

Edit: Oops, posted a little late. I'll do that Mohamed. I'll leave in about 5 min.

 

Ok, I went to AutoZone, but they can't pull the codes anymore, because California passed some law that fines them $300 for every code. The guy there was really cool, and gave me 2 phone #'s to see how much each would charge me, if they even do. I'll hopefully have the code sometime today, and I'll put it up on here.

Thanks for all the help so far, this one thread has saved me $70.

 

since you've got a 91 p/u you should be able to read the codes with out an OBDII scanner.

theres a diagnostic box under the hood where you need to short out two terminals and when you turn the ignition on (but NOT start the engine) the CEL will blink in a certain pattern pertaining to whatever error code or codes is stored in the ECU.

ill try to find a link to the precedure somewhere for you...

 

check this out and tell us if it helps at all......


CLICK HERE

 

I did that, and I'm confused as hell. I wrote down how many times it flashed but I am still confused. Here is what I saw:

It flashed once, then about four seconds later it flashed 4 times, then about two seconds later it flashed 4 times, then another two seconds and it flashed 3 times, another two seconds and it flashed 7 times, two seconds again, then one flash. I think that's it, because it repeated that same thing again.

I'm so confused, but if anybody can make heads or tails of this, I wont have to have it checked. Which is a plus.

 

Okay so based on the link posted,

1) you said it flashed once, and then four seconds later flashed four flashes.

code 1 or code 14

2) then four seconds later four flashes, then you said it flashed three times followed by two seconds and then seven times, then a flash.

code 13 and a code 71

I dunno, that's my guess. something like an ignition that is cutting out problem? Try replacing spark plugs, wires, and distributor? Anyone else?

 

Looks like EGR and an ignition problem at once.
One problem is likely causing all the codes tho.
Hopefully other 2nd gens will help out here.

 

can you make a mpg and post it somewhere where we can look at the CE light flashing....

 

yea im guessing the EGR might be screwing stuff up............its possible that its clogged up and just needs to be cleaned

 

I have no way to make a movie. I wish I did.

All of these things you are suggesting I have no clue about, so I need kinda detailed fixes, if it's possible.

This website is great, because of the members like you guys.

I'll have to mess more with it tomorrow, it's dark and raining. Any more ideas would be great.

Thanks!

 

you might wanna try to clean out the filter on this first............then maybe check the vacuum hoes and make sure theyre not cracked or disconnected

then dont forget to reset the ECU by disconnecting the battery for a while (this should reset the CEL) then go for a drive and see if the light comes back on

 

I'll check that out tomorrow.

What is the EGR system? What does it do?

Sorry for all of the questions, I just want to learn about this stuff while I fix it. That's how I learned everything I know about cars. I'd see what happens when I messed with something. Kinda dangerous, but oh well.

 

The EGR valve is part of the pollution control system, "EGR" stands for "Exhaust Gas Recycler". It's purpose in life is to get the engine to re-breath some of the exhaust gases in order to cut down on nasty suff coming out the tailpipe.

 

Cool, thanks.

 

Ok, so I opened up the EGR vacuum modulator, and instead of seeing filters, I see something like this:



It's like a thick, cotton ball type thing that is completely stained dark black. Am I right in assuming that this isn't the filter? And where would I go about purchasing the correct filter? Would an Autozone or Pep Boys type store have one?

I am also changing all of the spark plugs and wires and all of that today.

If this doesn't fix the problem what else should I try?