No Start Fixed, Need to track down RPM Drop Problem.

[xxShaneOmac]

One Day after replacing the battery in my car it decided to just die. I had the car at idle sitting in my driveway for 10 minutes and it just randomly died. Started it back up and it died after 5 minutes. Started it back up and it died in 2 minutes. Each time the car started perfect and ran perfect until it just died quicker and quicker each time.

After like the 5th start it would not longer start and would just crank non stop. I went down the list and had spark fuel air and timing. I replaced Coolant temp sensor, spark plugs / wire to test, fixed all Boost leaks and adjusted fuel pressure.

After being stumped for a while I took out the plugs and checked them, they were black with gas so I replaced them again and dropped a step to stock plugs. (From 7's to 6's) When trying to start it this time It still didnt want to start after cranking for 20 seconds. For some reason I then stepped on the gas and the car started but had the roughest idle I have seen on my car yet and if I let off the gas It would die.

After Holding the gas on long enough for the car to get warm the idle smoothed out and was just low @ 600 but steady. I Set DSMLink to 1000 and that did nothing to change my idle, so I adjusted my biss screw to get it to 1000.

Now the Car is warmed up and everything seems great, runs perfect, starts perfect idles great.

With that being said when I try to start the car when its NOT warm, on a cold start it will start now but it drops to like 100 rpm's and dies 50% of the time unless I throttle the gas. Once It gets a bit warmer, 1-2 minutes it all settles out and runs fine.

One thing to note is that when I turn on AC / Use my Power windows / seats or music etc hell even break or turn the steering wheel my RPM's drop anywhere from 50-200+ and my lights dim slightly on the dash.


Now that the terrible no start is fixed...... I still dont know why or understand it but I want to figure out how to fix this RPM Drop when the car is cold / using power accessories. What is my standered list of culprits to go and test?

Thanks for reading the lost post, just hoping to provide all info required. Mods are up to date in my profile.

 

[WES_393]

First, your main issue sounds like a voltage problem, possibly the alternator. Have you checked voltage through DSMlink?

When you adjusted the BISS, did you ground the diagnostics pin in Link? What's your ISC position at warm idle?

 

[xxShaneOmac]

First, your main issue sounds like a voltage problem, possibly the alternator. Have you checked voltage through DSMlink?

When you adjusted the BISS, did you ground the diagnostics pin in Link? What's your ISC position at warm idle?

Actually I didn't ground anything with Link while doing the BISS Adjustment, I didn't even know about that. I have owned the car for 6 years now and never have touched the BISS, it has always had a rock steady idle up until this problem.

I will have to read into that and make sure I do that, as well I will get the ISC Position / voltage readings from DSMLink. **Edit that is if I can get the ISC Position from DMSLink 2.0. Ill have to check it out.

Thanks for the quick reply.

Edit #2
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Ok here is the log that I just ran. I guess Im behind the times quite a bit as its .dat and logged with V2 of DSMLink. I will have to upgrade at least my software to V3 ifnot the whole package once I get things ironed out.

I actually had to install XP Mode on my Win7 machine to get DSMLink 2.0 to work

So I took note of what my ISCPosition was while the car was warming up, it was hard 120 for a while, once Cooltmp got to 170 it started to lower to 100 then 190 temp was like 70 or something and as you see in the log 200+ temps settles the ISCPosition at or around 8.

Throtpos and Idlesw show that my throttle cable isnt pinned down at idle.

I logged Battery and its 13.5v +/- .3v and also had RawBatVolts @ 190 or so.

Does this info work or do I need to gather some more? Thanks

I'm guessing I should Ground Diag in DSMLink and adjust BISS until Im at 30? ISCPosition when the car is warm?

Do I ground Timing as well or just Diag? Is there a link for this how to?