High rpm miss - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 08-05-2003, 05:44 PM   #1
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default High rpm miss

Yup. It'* puking. Mostly in passing. Plugs and wires are new, only happening at high rpm'* under load. No codes, data stream is clean.
willwren is offline   Reply With Quote
Old 08-05-2003, 06:33 PM   #2
Senior Member
Posts like a Turbo
 
Join Date: Jul 2003
Location: Boston Area
Posts: 327
Thanks: 0
Thanked 0 Times in 0 Posts
TelePlayer is on a distinguished road
Default

Weak spark? BTW what are you using for plugs, Will?

Steve
TelePlayer is offline   Reply With Quote
Old 08-05-2003, 07:36 PM   #3
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

NGK Vpower TR55'*. I'm thinking shitty alternator, and low voltage at high rpm dropout. My alt is an autozone special, only 105 amps. (emergency install).

Anyone else buy this theory? I'm planning to put the scantool on tonight and go for a sprint, watch the alt charge line and my voltmeter.
willwren is offline   Reply With Quote
Old 08-05-2003, 07:50 PM   #4
Senior Member
Posts like a Turbo
 
Join Date: Jul 2003
Location: Boston Area
Posts: 327
Thanks: 0
Thanked 0 Times in 0 Posts
TelePlayer is on a distinguished road
Default

I don't know. The car itself won't pull too many amps. It'* things like the windows, sunroof and rear defroster that require all those amps. I would be surprised if the voltage ever goes below 13 V. Unless the alt is toast, of course.

I have the autozone lifetime alt. So far so good. Not sure how many amps it is. When I got it, I made them switch the pulleys because the one on the autozone didn't run true with the shaft. They thought I was nuts but too bad.
TelePlayer is offline   Reply With Quote
Old 08-06-2003, 01:15 AM   #5
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

Anyone got any other ideas besides the alt?
willwren is offline   Reply With Quote
Old 08-06-2003, 01:28 AM   #6
Senior Member
True Car Nut
 
Join Date: Oct 2002
Location: Genoa, Illinois
Posts: 4,013
Thanks: 0
Thanked 0 Times in 0 Posts
Allmachtige is on a distinguished road
Default

You sure its a miss? First thing that popped into my mind was EGR, but that usually can only be detected at low cruising rpm'*.
Allmachtige is offline   Reply With Quote
Old 08-06-2003, 02:07 AM   #7
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

If it'* the EGR, I'd be throwing codes. No codes.
willwren is offline   Reply With Quote
Old 08-06-2003, 03:32 AM   #8
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

Ok, on the way home from work tonight using the scantool:

Headlights and foglights on, stereo off. Radar off.

Volts on idle: 13.4
Volts on Decelleration: 13.6
Volts on cruise: 13.4
Volts on ACCELLERATION @ 2500-3000 rpms: 13.0

Is this my problem? Is the ignition system that sensitive to a weak alternator? I'm assuming IF this is what'* causing misfires (or just weak fires, since the PCM isn't reporting a misfire) my plugs are probably fouling also.
willwren is offline   Reply With Quote
Old 08-06-2003, 04:37 AM   #9
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

Quote:
Originally Posted by jr's3800
Quote:
Originally Posted by willwren
Ok, on the way home from work tonight using the scantool:

Headlights and foglights on, stereo off. Radar off.

Volts on idle: 13.4
Volts on Decelleration: 13.6
Volts on cruise: 13.4
Volts on ACCELLERATION @ 2500-3000 rpms: 13.0

Is this my problem? Is the ignition system that sensitive to a weak alternator? I'm assuming IF this is what'* causing misfires (or just weak fires, since the PCM isn't reporting a misfire) my plugs are probably fouling also.
Check your plugs first..... You might have an unhappy camper... Your autozone special is functioning for now... I however don't like how its loosing voltage on acceleration.... Usually it'll be a bit higher... but the unit falls in the proper operating range... I have the same alt you do on my 91 bonneville and its usually at 13.5 to 14v for just abotu all driving situations... You may even have a clogged or dirty fuel injector... Does the miss happen a lot of just every now and again under acceleration? Check the plugs first and number them according to the cylinder number they came out of and have a good look at all of them...
I'd buy a fouled plug before an injector. It smells rich when I get out of the car after a 'misfire' run. It'* a heavy miss. Feels like at least 1 or 2 cylinders missing at the same time. If I nurse it along under 2500 rpms, I don't get it at all. I'm not running lean, so I know it'* not fuel delivery related, and all my injectors were cleaned when I did the Eaton rebuild. Filter is fairly new too.

I'll have to pull and inspect plugs next I suppose. Might be a couple days before I have time.
willwren is offline   Reply With Quote
Old 08-06-2003, 04:47 AM   #10
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

Wouldn't my ICM detect a misfire in that situation?
willwren is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
High rpm miss 97BONNIESE 1992-1999 7 09-07-2009 08:47 PM
car idles @ 3500 rpm at start and 1900 rpm in drive? 88bonnsse 1987-1991 15 01-27-2008 04:41 AM
Slight miss 1500-2000 RPM **FIXED** Scrangler83 1987-1991 14 04-04-2005 04:28 AM
Engine miss between 3-4k rpm, '94 Olds 88 LSS... dbtk2 1992-1999 7 02-13-2005 11:05 AM
Please help (hi rpm miss) Red Baron 1992-1999 11 01-06-2004 09:55 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 03:31 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.