Ok I was cruising out to lunch yesterday from school when I noticed my car being very ruff at low rpms. I think is was possibly missing. Once I got about 2,500rpms it smoothed on out and ran like normal but any time I was below that and gave it any large amount of throttle it would become lumpy.

After TKD practice I came back out to the car and cranked it up. It cranked up very lumpy like it was camming really bad. The only thing is that it never cleared up even once I got over 2,500rpms. It was very similar to when my cam gears were both on full advance just not as bad. The exhaust note is kinda like "braaaaaap" when I'm cruising. I'm also getting a constant flashing CEL. The car isn't jerky or anything now its just constantly acting like it has some nasty cams.

I figured it was my VAFC which I didn't solder in so that was the first thing I did today. I went back on soldered every connection then reset the ECU and cleared the VAFC. Nothing changed.

Checked the cam gears and they are one the exact same settings as I left them. Distributor is bolted down tight.

Its throwing a code 71-74 which is a misfire code on every cylinder. Its also doing something very weird. Its throwing 3 short flashes and thats it. Its not preceded by any slow flashes.

I also have an idea that it could be bad gas. Everything started to happen when I was on empty. I have filled up again and ran almost 200mi (I had to get back from school) without any change. Is it possible that it detected bad gas and retarded the timing a whole bunch? The only thing i don't get is that it should have cleared it up for a bit when I reset the ECU.

My mods are Skunk II stage one cams with STR cam gears and a VAFC. I've put more than a 1500mi on the cams without a problem so I doubt thats it.

 

brock is a good guy , somebody help him out

 

Code 3 - MAP Sensor (Manifold Absolute Pressure) defective circuit or unplugged / defective sensor

Take a look at that and just for fun, make sure all plugs are tight.

 

More than likely the vafc. mine did the same thing when the connection came loose on the back of the unit. the computer goes into full rich limp mode.

 

Yeah I thought that might be it but I went ahead and soldered all of the connections.

I'll check on that map sensor. My VAFC is still reading the pressure which I assume is the manifold pressure so would this prove it to be working?

 

Ok I never knew that it would throw short flashes for a single digit code. I thought it would throw three long ones but that makes more sense now. So basically its my map sensore. Now I just have to figure out if its the VAFC causing it or the sensor.

 

Bump because I want a little more input just incase for tommorrow.

 

I had the EXACT problem. I think bad gas caused myne aslo. I changed my plugs even though they didnt look that bad and it ran like new. BTW the plugs that were in my car at the time were fairly new. I would sugest to switch your spark plugs and watch the gas you use.

 

My set of plugs I ordered just came in today too. Maybe its a sign.

 

Yes god is telling you to change your plugs!

hehe... I have $$money$$ that says when you change your plugs your problem goes away. Let us know.

 

I would also say to check the plugs.

BTW, what plugs did you get?

 

MAP code to me makes me think VAFC wiring. or it could be the settings on the VAFC. I threw a map code when adding in too much fuel before.

otherwise it's ignition related, plugs/wires/cap/rotor/ignitor/etc just start checking it out.

 

Apparently it was bad gas. I checked the plugs and they were pretty messed up. In fact I don't even know if the #1 cylinder was even firing. I popped in a new set of NGK's and its purring like a kitten again (well as much as it did before at least).


[Modified by ActiveAero, 9:17 AM 2/26/2003]