86 LXI stalls when put in gear

[petes_86lxi]

Hi, I have an 86 LXI that has run great for years. Recently, a few weeks after installing a new intake, I've run into some problems. The car starts great, but when put into gear it runs terribly and will stall unless I really hit the gas. After a few minutes of driving and stalling, the PGM FI light comes on, and the problem goes away. 2 questions:
1. How do I check the codes? I found the viewing portal under the driver's seat on the ECU, and it's blank at idle. Am I doing this right?
2. My mechanic unplugged a sensor for me, and now the car does not have this problem, but PGM FI light is always on, and the car is extremely difficult to start cold first thing in the morning.

Is my ECU just bad? Thanks.

[anchovies]

Put the key to ON position then read the blinks.
Probably the eacv.

[petes_86lxi]

Hey, I put the key in the ON position (assuming that's the one just before it cranks), and the position before that as well, and still get no lights in the LED. I checked the fuses for the ECU, they're fine.

[88LX-iSedan]

Maybe it's not plugged up. I have no idea what im talking about so.. It's just a suggestion.

[88LXi/87CRXSi]

Originally posted by petes_86lxi


Is my ECU just bad?

OK, not sure if this applies to a 86, but in a footnote under a chart in my "88 manual it says

When the check engine warning light is on with no blinks on the self diagnosis indicator, the back-up system is in operation.
Exactly what kind of mechanic did you trust your car to? You gotta get things cleared up dude, or the cars gonna run like sh*t!

Might want to try plugging in what the mech unplugged, pull the ecu fuse for a few minutes, then start it. When the CEL comes back on , see if the led starts blinking a code. Then get back to us.

*Edit*-
Doing more reading I found this note, not good! Under description of Pgm-fi:

2. Back-up function when an abnormality occurs in the ECU itself. the injections sre controlled by a back-up circuit independent of the system in order to permit minimal driving.

Man I hope all this is wrong for your sake!!!:crying:

[petes_86lxi]

Thanks for the suggestions. Just a couple of questions. You say pull the ecu fuse for a few minutes, and then start the engine and check the led after the CEL light comes on.
Did you mean to say, pull the fuse, wait for a few minutes, and then replace it? I did actually try that already. I pulled the fuse for 5 minutes to reset the ecu, replaced it, started it and still no codes.
When you say CEL light, do you mean the pgm-fi light? Thanks.

Well, if it is in fact the ECU, I can get a salvaged one for under a hundred bucks.....:pimp:

[netfreak]

Just disconnect the battery for a few minutes.

[88LXi/87CRXSi]

Yeah, that's what I meant to say! And yes the dash light! Sorry for any confusion.
That stuff I posted isn't listed in Paul's '86 manual tho. Might be a good idea to download at least the FI section he added, section !2, fuel and emissions FI.
Could also be something stupid like a broken ground wire.

[petes_86lxi]

Ok, tried again after work. All sensors plugged in, I started the car and drove around for a few minutes with it performing terribly. When the light came on, and the performance dramatically improved, I checked the ECU again. It turns out it flashes now, 12 times! The documentation on this site states it's something with the EGR LIFT SENSOR. I'll investigate this, can anybody tell me what this EGR valve looks like, or have a clear photo?

[88LXi/87CRXSi]

Glad to hear you're getting somewhere and the ecu isn't trash!
I don't know whose engine is in this pic, but that shoud be the lift sensor on top of the egr valve. You should see a tube running to the exhaust manifold connected to the valve.

[cruznz]

Originally posted by petes_86lxi
2. My mechanic unplugged a sensor for me, and now the car does not have this problem, but PGM FI light is always on, and the car is extremely difficult to start cold first thing in the morning.

Is my ECU just bad? Thanks. [/B]

the pgm-fi lioght is on because the sensor is unplugged, since the problem went away when this sensor was unplugged....1 could assume that this sensor was the fault in the first place.

try replacing this sensor and see what happens

[cruznz]

:rolleyes: ...hmmm, i was abit late with that reply...lol...:D

[petes_86lxi]

Thanks Pete, I need to confirm with my mechanic what sensor he plugged in. The thing is, it starts just fine when I plug it back in, but runs horribly and stalls when I place it in gear. This lasts for about 5 minutes, and then the PGM FI light comes on and the poor performance in gear goes away, with ECU LED error 12. I'm going to have to test some stuff this weekend and see what happens.

[86hatchbackLXi]

mine did the exact same thing when i put on my intake. i had 2 extra vacuum lines. currently one is plugged and 1 is open and the cars runs fine now, when i had them both plugged the car would run rough and then stall when i put it in gear. play around with the lines becuase thats what the problem is. i have an 86 lxi as well

[petes_86lxi]

I'll definitely try what you suggest with the extra vacum lines. I also had these extra 2 lines, both going into the emissions box. I ended up using a Tee and connecting them both to the intake.