car likes to choke/dog down sometimes

[Austins01GP]

Every once and awhile my 2005 grand prix comp g likes to not want to accelerate and feels like it's misfiring. It will do this from start up until it's stopped. Most of the time if I shut it off it will restart and be just fine. I have been just dealing with it for a while but recently it's become more frequent and back to back one time and thst bothers me. (Scan Guage doesn't read misfires)

[FordMan77]

Clean the throttle body lately? If not I'd start there.

[Austins01GP]

Yeah I already tried that. Also changed the icm, had a spare one laying around

[Fivefingerdeathpunch]

Get a scanner than can read what you want to see.

We can't just guess at this stuff, we can't see this issue infront of us.

Figure out if it's really a misfire or something else, the scanner is the best bet to diag any issue like this. Knowing what is happening in real time is the only way to figure this out.

[J57ltr]

Does it just lay over and seems to have no power? Watch the timing when it does this.

Jeff

[Austins01GP]

I'll watch the ign timing next time it happens on my scan gauge. Any other parameters I should watch?

[J57ltr]

KR, Map and MAF

[Fivefingerdeathpunch]

It's useless to scan those if he doesnt even know what the numbers will mean.

Only clear cut answer would come if the MAP just whacked out and starts spraying out numbers that arent really happening at the time or the MAF drops out.

I'd still get a better scanner that can possible see real time misfire to watch every cylinder to determine an electrical/spark issue.

[Austins01GP]

Yeah i dont know what numbers should be coming out of maf/map sensors. i have been watching the ig timing and nothing out of the ordinary seems to be shown when its choking. I watched for misfires when it was occurring and a total of 2 on cylinder 3 showed up (drove several blocks). so im betting its not spark/fuel related

[J57ltr]

Mine did it this morning and when I am usually showing about 35-40* of timing it dropped to 20 and I knew it was showing KR and usually it shows about 15* when it does that. I was still rolling and shut the car off and restarted it and the timing came back to where it should be drove the rest of the way to work and it was fine. I have not been able to look at timing AND KR at the same time on mine so I either have one or the other up.

Jeff

[Austins01GP]

Sounds exactly like mine, I'm watching my timing but haven't noticed that much of a change

[J57ltr]

Select Knock Retard and watch that. You may have better luck than me and be able to watch timing and Knock Retard on the App. Mine seems to have to look at different protocols for KR and Timing. Make sure to select gauges that show minimum and maximum values. Sometimes things happen that you can't really watch but will be displayed as high or low. When I first got my car I would have times where it would crater the timing at -15* (15* ATDC) and the car would really fall flat, I doubt you are seeing that. You won't really have timing values less that 15* unless you have it at a hot Idle in park or neutral and it will be about 3-8*, or sometimes in gear it might drop to 5* when decelerating but you will only be worried about accelerating. Just reset the min/max when you need to. Mine happens so infrequently that it's hard to catch unless you have the app up all the time. I have only one DHP log file where I catch it happening.

Jeff