98 formula allergic to throttle - LS1TECH

Log In 


General Maintenance & Repairs Leaks | Squeaks | Clunks | Rattles | Grinds

98 formula allergic to throttle

Reply
 
Thread Tools Search this Thread
Old 09-19-2011, 12:05 AM   #1
TECH Addict
Thread Starter
iTrader: (13)
 
chrysler kid's Avatar
 
Join Date: Feb 2005
Location: Mckinney Plano Frisco
Posts: 2,045
Default 98 formula allergic to throttle

Guys I'm having an issue I can't figure out with my formula. The only code being thrown is for mass air low voltage which I replaced with a reman from auto zone.
I reset the battery and the car will barely idle. It lopes like it's firing one cylinder at a time, and if I give it any throttle it absolutely dies.

The idle eventually evens out and the car will idle normally however it only feels like it's making 150 horsepower above 3500 rpms.

I sprayed around the engine with carb cleaner checking for any vacuum leaks but didn't find any.

I'm at my wits end with this thing, about to have it towed to kcm
chrysler kid is offline   Reply With Quote
Old 09-19-2011, 12:22 AM   #2
9 Second Club
iTrader: (21)
 
Slash8915's Avatar
 
Join Date: Mar 2008
Location: League City, Texas
Posts: 617
Default

Bad o2? Burned valve? Maf?
Slash8915 is offline   Reply With Quote
Old 09-19-2011, 02:13 AM   #3
TECH Addict
Thread Starter
iTrader: (13)
 
chrysler kid's Avatar
 
Join Date: Feb 2005
Location: Mckinney Plano Frisco
Posts: 2,045
Default

Just put a new MAF in there. Tried others from one of my other fbodies without success. When i unplug the MAF it doesnt help the car with its issues
chrysler kid is offline   Reply With Quote
Old 09-19-2011, 02:17 AM   #4
Launching!
iTrader: (1)
 
LS1TA_956's Avatar
 
Join Date: Jul 2011
Location: Laredo
Posts: 267
Default

Maybe somthing wrong with the maf connector make sure its not damaged
LS1TA_956 is offline   Reply With Quote
Old 09-19-2011, 02:55 AM   #5
TECH Addict
Thread Starter
iTrader: (13)
 
chrysler kid's Avatar
 
Join Date: Feb 2005
Location: Mckinney Plano Frisco
Posts: 2,045
Default

ill take a look at the harness tomorrow but it looked ok when i inspected it.

burnt valve? im not sure, the top end does not make any abnormal noise knocks or ticks but the car runs rich as a saudi

ok so next question, i have heard that if you have an 02 sensor fray on a header it will blow a fuse to the motor that will cause the engine to read low voltage to MAF. anyone remember what fuse that was?
chrysler kid is offline   Reply With Quote
Old 09-19-2011, 12:29 PM   #6
Teching In
iTrader: (9)
 
slohemi's Avatar
 
Join Date: Oct 2007
Location: Spring TX
Posts: 44
Default

It's the engine sensor fuse. When mine popped, the car would get stuck between 1500-2000rpms then settled back down once i stopped. Also felt like a complete turd but it didnt die or misfire. I was throwing codes for the front O2's, MAF,Skip shift, and reverse lockout when mine blew so idk if thats your problem.
slohemi is offline   Reply With Quote
Old 09-19-2011, 04:07 PM   #7
TECH Enthusiast
iTrader: (5)
 
Join Date: Nov 2001
Location: AZ
Posts: 663
Default

If you did a reset (disconnected battery), it will barely idle until it does a relearn, which shouldn't take more than one drive around.
As for the code, need to check for 5V on one of the MAF plug wires (don't recall which one, but with the key on, one will be +5, one will be gnd). Just check with it unplugged, key on but not running.
patSS/00 is offline   Reply With Quote
Old 09-19-2011, 10:52 PM   #8
TECH Addict
Thread Starter
iTrader: (13)
 
chrysler kid's Avatar
 
Join Date: Feb 2005
Location: Mckinney Plano Frisco
Posts: 2,045
Default

Yeah that's the problem though after a hard reset I can't drive it around, it will die.

Checked the engine sensor fuse, seems to look fine. Car is an a4 so no skip shift but it has the same symptoms
chrysler kid is offline   Reply With Quote
Old 10-30-2011, 09:23 PM   #9
TECH Addict
Thread Starter
iTrader: (13)
 
chrysler kid's Avatar
 
Join Date: Feb 2005
Location: Mckinney Plano Frisco
Posts: 2,045
Default

still need help. changed plugs, wires, intake manifold
chrysler kid is offline   Reply With Quote
Old 10-30-2011, 09:50 PM   #10
TECH Resident
iTrader: (18)
 
chevymec's Avatar
 
Join Date: Jul 2004
Location: Richlands N.C.
Posts: 875
Default

Clogged fuel filter or failing fuel pump? You need to check you basics first and see if you can get a scanner on it to look at readings.
chevymec is offline   Reply With Quote
Old 10-31-2011, 09:01 PM   #11
TECH Addict
Thread Starter
iTrader: (13)
 
chrysler kid's Avatar
 
Join Date: Feb 2005
Location: Mckinney Plano Frisco
Posts: 2,045
Default

Changed Maf no improvement
Changed fuel filter no improvement
Changed plugs and wires no improvement
Changed o2 sensors no improvement
Changed throttle position sensor no improvement

No check engine lights
chrysler kid is offline   Reply With Quote
Old 10-31-2011, 09:05 PM   #12
TECH Addict
Thread Starter
iTrader: (13)
 
chrysler kid's Avatar
 
Join Date: Feb 2005
Location: Mckinney Plano Frisco
Posts: 2,045
Default

Oh and when I say changed I mean all new units.

Now it's not making any power at all. It misses when you give it partial throttle, full throttle any throttle. No check engine lights no codes, nothing.
chrysler kid is offline   Reply With Quote
Old 10-31-2011, 09:08 PM   #13
TECH Addict
Thread Starter
iTrader: (13)
 
chrysler kid's Avatar
 
Join Date: Feb 2005
Location: Mckinney Plano Frisco
Posts: 2,045
Default

I forgot to mention I deleted the egr when I did the ls6 swap and it's not triggering a code for that either
chrysler kid is offline   Reply With Quote
Old 10-31-2011, 09:19 PM   #14
TECH Resident
iTrader: (8)
 
metalmilitia606's Avatar
 
Join Date: Sep 2009
Location: Dayton Ohio
Posts: 860
Default

Quote:
Originally Posted by chrysler kid View Post
I forgot to mention I deleted the egr when I did the ls6 swap and it's not triggering a code for that either
You should have got a code on that one. Maybe your issue is computer related.
metalmilitia606 is offline   Reply With Quote
Old 10-31-2011, 09:38 PM   #15
TECH Resident
iTrader: (18)
 
chevymec's Avatar
 
Join Date: Jul 2004
Location: Richlands N.C.
Posts: 875
Default

What is the fuel pressure?

Edit: Also you might have a clogged cat. Try taking the upstream O2 sensors out and see if you power comes back.
chevymec is offline   Reply With Quote
Old 10-31-2011, 10:36 PM   #16
TECH Addict
Thread Starter
iTrader: (13)
 
chrysler kid's Avatar
 
Join Date: Feb 2005
Location: Mckinney Plano Frisco
Posts: 2,045
Default

car has midlength headers x pipe and o2 sims. i purchased the car from the previous owner who put in a 99 motor and a4 transmission on a 98 a4 engine harness.

im thinking it is computer related. going to see if i can get some one locally to scan the car. when i mash the throttle the car does nothing, acts like it should just be idling.

not sure about fuel pressure. before i changed the o2 sensors the car reeked of fuel coming out the exhaust at idle
chrysler kid is offline   Reply With Quote
Old 10-31-2011, 11:46 PM   #17
TECH Addict
Thread Starter
iTrader: (13)
 
chrysler kid's Avatar
 
Join Date: Feb 2005
Location: Mckinney Plano Frisco
Posts: 2,045
Default

youve got to be kidding me

i ran it around town got it warmed up but the temp gauge still showed cold. so i went under the hood and un plugged the coolant temperature sensor in the head

went and started it up and it did not have the starting issue it has been having. it started instantly and blew a bunch of smoke out of the tail pipes.

so the throttle issue is resolved, the starting issue is resolved, the only problem it has now is the car wont rev past 3 grand which im sure is the computer limiting the rpms because of no temperature reading (the needle on the dash now reads below zero)

going to have to make it to GM tomorrow to order the 3 pin 98 sensor that goes in the head
chrysler kid is offline   Reply With Quote
Reply


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 On
Refbacks are Off



All times are GMT -5. The time now is 03:42 PM.