Quick question

Rickw wrote:

L67 wrote:

My faulty MAF has set my SES and trac control lights.

how does it set a "Traction Control Off" Light.?
I can understand the SES light, but TCS......

I'm not sure, whenever I clear the code the TCS light turns off.

Thanks everyone. I thought of just a bad wheel sensor, but it's not a HUGE concern at the moment, but I thought it might be connected to the SES light/idle problems. I know this is a complicated one, but I really do appreciate the help. I should have cleaned my IAC valve when I had my supercharger off last. Damn. Now I'll have to spend 20 minutes getting to the screws for it lol. Oh well. It's definitely worth the time to try that too while I wait for my scanner.

I was pretty sure the MAF MIGHT have something to do with my lean condition in a way, but these cars are so complicated there's different opinions across the board. I'm going to go after the IAC tomorrow if I can. My MAF is clean but I'm going to wait until I get my scanner to see what it's deal is.

I used throttle body cleaner to clean the IAC on my Lesabre T-type. Is that still the preferred cleaner for the IAC? Thanks!

maf cleaner is better. a good soaking will allow carb cleaner into the elec connections of the IAC. might not be good so dont chance it. why do you have to remove the s/c to get at your IAC? its to the right of your egr pipe where it connects to the throttle body ...

I didn't mean I have to remove the supercharger, I just mean it'd be easier to get at the screws that way. I'm not complaining about it i just wish I had done it while the supercharger was off before with the throttle body still attached . I'll try to clean it tomorrow since I'm sure it is actually dirty and report back. Thanks!

Quote :

I'm not sure, whenever I clear the code the TCS light turns off.

This is because you are probably clearing multiple codes at the same time. The scanner may not list the ABS code, but you are clearing it when you "clear codes" to shut off the SES light. It shouldn't have anything to do with MAF sensor or lean condition codes.

l67 wrote:
I'm not sure, whenever I clear the code the TCS light turns off
off topic but what kind of scanner do you have?

so how did things turn out z-type?

AA wrote:

Quote :

I'm not sure, whenever I clear the code the TCS light turns off.

This is because you are probably clearing multiple codes at the same time. The scanner may not list the ABS code, but you are clearing it when you "clear codes" to shut off the SES light. It shouldn't have anything to do with MAF sensor or lean condition codes.

I only have one DTC at the moment, P0102. My TC light was on for my P0341 code but that code was remedied with a wire fix. When my MAF was working for about twenty minutes the TC/SES lights were off and both only returned when the MAF died and the P0102 returned...

robotennis61 wrote:

l67 wrote:
I'm not sure, whenever I clear the code the TCS light turns off
off topic but what kind of scanner do you have?

DHP PowrTuner

Thing will be progressing tomorrow after work, Robo. I just got my scanner in! I can't wait to fire it up and do some investigating and poking around.

Again, just to reiterate the intermittent - ness of this situation, I haven't even seen my engine light for a week, However, in the meantime, I took this video about a week and a half ago when my engine light was on and my idle problem was present.

http://www.zamiska.net/z/idleproblem.avi

Good call getting the scanner. Now you'll wonder how you ever got by without one!

I agree AA! I can't wait to get using it. I don't have time to mess with it tonight AGAIN because i worked 7 hours overtime. I read about it last night and I'm looking forward to its features. Hopefully I'll get home tomorrow when I'm supposed to, AND when it's daylight, and get some diagnostics done on the car. I'll let you know what I find if anything is anomalous.

Ah-ha! The scanner works! It read the stored code on my computer successfully and was able to check out the LONG LONG LONG list of diagnostic information I can view, recorded or live. I'm blown away. I'm going to take a ride tomorrow and try to record some of the information for sensors and things. For instance, the EGR operation, MAF operation, etc. Things related to my problem at first. What all should I look at?? I can view about.....25 or more diagnostic levels and things. Thanks guys!

Try monitoring the MAF Hz reading while driving. You could also let it idle and have someone monitor the Hz while you wiggle around some wires to see if you get any 0's. If you get intermittent 0 readings you may have a damaged wire. If the reading is consistently low (not sure exactly what it should read in real time driving but idle is ~3000 Hz IIRC, so above 3000 in normal operation sounds about right) then you may have a faulty MAF sensor.

what kind of scanner did you get and what ya pay for it?

Thanks L67. It came with an 8-foot extension cable so hopefully I can do that kind of thing myself. I'll try that tomorrow!

Robo - this is the scanner I got:

Link

I got mine for $90 from there though. Looks like the price went up! I recommend it for us '95's though, since it's cheap and we know it works. It'll work for just about any car from '86(?) to '04 or '05. If you want OBD1 though ('93 and prior) you need to the OBD1 cable separately,which I did since I have several OBD1 cars around here.

I'll report back some numbers tomorrow, at idle and driving. We'll see what's what, since I don't know what I'm necessarily looking at number- or reading-wise. I just know that the scanner works lol.

Thanks!

Look at LTFT. It gives you an indicator of how much fuel is being added or trimmed by the PCM. A positive number means the computer is adding (lean mix), a negative value means fuel is being cut (rich). The closer you are to zero, the more optimum & consistent your air/fuel mix is, and the easier the PCM's job at making the correction.

Ok - we have progress.

I drove the car to do a few errands today to get it all used and warmed up right and blah blah blah. The car was great through all that driving, and the scanner agreed with me, except for one thing....

The LTFT, as you stated AA. When the car was just on battery power, it read 128, idling in park and in drive was 159. I don't know what those numbers mean but I sure as heck know it's not 0. Obviously, this is consistent with the Fuel Trim Lean code I'm getting on the PCM. It was pretty steady at that number. There was another number under that called LTFT CL, and it read 15 to 17 while the car was idling in park or drive. Any info on that subject?

Also, I noticed some consistency with my idling problem and my Lean problem. As my idling problem came about, my engine light was not on, but once the engine had its idling problem for a bit, the light DID come on. That's happened the last several times the idling problem has come up. Consistency is good. So, the important thing I noticed is that my battery volts would drop to 12, THEN my idle would drop to 500, climb back up, and my volts would then also climb back up to 14.7. My battery is brand new, FYI. In addition to this, I discovered (written in another post of mine) that my alternator pulley has a VERY VERY slight wobble. Also, my alternator belt tensioner pulley may be going bad too, but it's hard to tell.

In review, my EGR, EVAP, MAF, and TPS are all reading normally even during my idle fluctuations and engine light being on, I think. In idle, my EVAP was open 15%, which I assume is normal. My EGR volts were at 0.8. My IAC was 40-45, even during my idling fluctuations.

If anyone can make any sense or connections between these problems, PLEASE let me know. I'm getting closer to fixing this mess and I'm getting excited that I might actually be able to fix it! Thanks everyone, and sorry for the information overload. I figured I'd put out there all that I noticed when I scanned the car.

Z-type wrote:

The LTFT, as you stated AA. When the car was just on battery power, it read 128, idling in park and in drive was 159. I don't know what those numbers mean but I sure as heck know it's not 0. Obviously, this is consistent with the Fuel Trim Lean code I'm getting on the PCM. It was pretty steady at that number. There was another number under that called LTFT CL, and it read 15 to 17 while the car was idling in park or drive. Any info on that subject?

Check out this thread, the trims on the OBD1.5 are a little different.

https://rivperformance.editboard.com/series-i-scans-tuning-f14/a-question-of-fuel-trims-t4986.htm

Hmm...after reading all that I wonder if I should double-check my fuel pressure? Thanks Karma that was a very informative bit of reading you sent me.

I just find it strange that the only thing I sense is amiss while my idling goes haywire and my engine light turns on that code is that the power drops to 12 volts, the idle drops, then both slowly climb back up and keep fluctuating. Why would that cause a lean condition? What could be causing my volts to drop like that in the first place?

Maybe the voltage drop isn't causing it, but is a result of something else. If the engine slows down, the alternator slows down, so you'll get less voltage. What we need to know is what is causing the engine to slow down. Whatever it is, that's probably causing your lean condition.

IF you're sure the voltage drop is happening first, you need to find out if there's a short somewhere. When does the drop occur? Do you have stereo or alarm equipment installed?

I'm sure the drop in voltage happens before the RPM drops. And it seems to be triggered by a revving of the engine, but only after a couple tries only at operating temperature. Then my engine goes nuts after that all by itself. This can happen in motion or at idle, but always after letting go of the throttle.

EDIT: And no there's nothing on the car not stock except for the air filter. All stereo equipment is stock and i don't think my alarm is hooked up.

I am wondering if maybe the voltage regulator (in the alternator) is malfunctioning.

Albertj

Is there any way a store like Advance Auto could test something like that?

I would hook up a fuel pressure gauge to the rail and watch fuel pressure at the same time your watching voltage and fuel trims. Try and find a correlation.
If the fuel pump is going bad and straining to keep up with demand it could be pulling too many amps. The easiest way to see that happening is if your watching fuel pressure and voltage at the same time.
Also watch fuel trim numbers closely with voltage fluctuation and record what it's doing, how close are any of these things fluctuating.
Meaning are things happening at the exact same time or something slightly before or after the other.
Your getting closer to finding out what it is, just need to look with a magnifying glass now, if you know what i mean. A good fuel pressure gauge can be bought a AutoZone for $30.00 if you don't already have one.

Z-type wrote:

Is there any way a store like Advance Auto could test something like that?

From what i know they can test your alternator off the vehicle on a test stand they have, they are able to load it down and see what it's doing. The only on car test that they probably can do would be to load test the battery and see what kind of voltage is being fed to the battery from the alternator.
That's if they even use the old type of load tester anymore. Most places have the electronic testers for the battery and that only tells you the health of the battery, they are not capable of putting a set load on the battery and watch what the alternator is doing.
I guess you could do the old school test by turning on everything possible on the car and see how the alternator reacts by reading voltage at the terminal on the back of the alternator.