still stuttering.....HELP! You techy dudes!!
Thread Starter
Instructor
Joined: Jun 2000
Posts: 183
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From: Olympia WA
still stuttering.....HELP! You techy dudes!!
Ok before I get all gung ho and buy a new MAF sensor....is there any "trouble shooting" or "testing" I can do to confirm that it IS the problem?
I posted my symptoms about a week ago...I have changed the fuel filter....hoping I just sucked up gunk, when I ran it low.....but no dice.
It still won't idle for long without dying. IF I unplug the MAF...it does seem to run better. However, before I actually buy a new one...is there any other items that may give me the same symptoms?
I posted my symptoms about a week ago...I have changed the fuel filter....hoping I just sucked up gunk, when I ran it low.....but no dice.
It still won't idle for long without dying. IF I unplug the MAF...it does seem to run better. However, before I actually buy a new one...is there any other items that may give me the same symptoms?
Race Director
Joined: Aug 2000
Posts: 14,130
Likes: 7
Cruise-In II Veteran
Re: still stuttering.....HELP! You techy dudes!! (LuVettes)
Do a fuel pressure check first...if it wont hold pressure,you may have a bad fuel pump.
Pressure should be at 35 psi-42 psi when the car is running and should not drop when you crack the throttle open some.
For now, did you have any check engine light codes?Was it the MAF code?
When the car is running,tap the MAF sensor with a piece of wood,just give it a little tap or jolt.If the idle stumbles and or stalls, you more then likely have a MAF problem.
I think the 85 uses a MAF module,and ill let the 85 guys answer that one.The later 86 and up cars had 2 relays one could change for the MAF power and burnoff.Im not too sure about the 85's set up.Thats something else that may be going south.
Craig marcho,you know this one?
:)
Pressure should be at 35 psi-42 psi when the car is running and should not drop when you crack the throttle open some.
For now, did you have any check engine light codes?Was it the MAF code?
When the car is running,tap the MAF sensor with a piece of wood,just give it a little tap or jolt.If the idle stumbles and or stalls, you more then likely have a MAF problem.
I think the 85 uses a MAF module,and ill let the 85 guys answer that one.The later 86 and up cars had 2 relays one could change for the MAF power and burnoff.Im not too sure about the 85's set up.Thats something else that may be going south.
Craig marcho,you know this one?
:)
Melting Slicks
Joined: Aug 2000
Posts: 2,009
Likes: 1
From: Springfield MO
Re: still stuttering.....HELP! You techy dudes!! (Bill's86Coupe)
I didn't read your other post but I assume you checked all of the plug wires and check all of the plugs themselves. A vacuum leak would cause a studder also. Sorry If I've repeated something thats already been said :bb
Thread Starter
Instructor
Joined: Jun 2000
Posts: 183
Likes: 0
From: Olympia WA
Re: still stuttering.....HELP! You techy dudes!! (Bill's86Coupe)
I did test the fuel pump...and I can definitely hear it working when I give it juice. I haven't tested the fuel pressure as I was told (by another mechanic friend) that it was rare that the pressure would be an issue if the pump is working.
The only code I get...is a code 12. Nothing else.
With the MAF plugged in....the thing coughs, sputters when giving it gas...and dies at the idle. With it unplugged...it seems to sound better.
The only code I get...is a code 12. Nothing else.
With the MAF plugged in....the thing coughs, sputters when giving it gas...and dies at the idle. With it unplugged...it seems to sound better.
Melting Slicks
Joined: Jun 2001
Posts: 2,525
Likes: 1
From: Sarasota, FL
Re: still stuttering.....HELP! You techy dudes!! (LuVettes)
I haven't tested the fuel pressure as I was told (by another mechanic friend) that it was rare that the pressure would be an issue if the pump is working.
Race Director
Joined: Aug 2000
Posts: 14,130
Likes: 7
Cruise-In II Veteran
Re: still stuttering.....HELP! You techy dudes!! (BobMachus)
Bob M is right, you need a pressure gauge to determine the real outcome.When my 91 Lumina,EFI,with speed density(no MAF) ran rough, the fuel pump primed just fine but wouldnt hold more then 25 lbs of pressure.Changing the pump fixed the problem.
Since you said it runs worse when the MAF is plugged in,the MAF is likely the culprit.Be sure the connections are clean and not broken as well.
Any good parts stores have rebuilt MAF sensors for a much cheaper price then a new one.You must give in your old core though.
But I hope some 85 guys chime in about any other items that may need checking or replacing.
Im sure some will soon.
Since you said it runs worse when the MAF is plugged in,the MAF is likely the culprit.Be sure the connections are clean and not broken as well.
Any good parts stores have rebuilt MAF sensors for a much cheaper price then a new one.You must give in your old core though.
But I hope some 85 guys chime in about any other items that may need checking or replacing.
Im sure some will soon.
Racer
Joined: Jul 2001
Posts: 443
Likes: 0
From: Tampa FL
Re: still stuttering.....HELP! You techy dudes!! (Bill's86Coupe)
it's definatly the maf if it idles and runs better when disconected.Try to find the maf without the heated wire it's much more durable . You should change relays also but I think the 85 uses different,more expensive relays then later years, only used in 85.
Melting Slicks
Joined: Aug 2001
Posts: 2,516
Likes: 0
From: Lockport NY
Re: still stuttering.....HELP! You techy dudes!! (LuVettes)
...is there any "trouble shooting" or "testing" I can do to confirm that it IS the problem?
Before *buying* anything, I would check for a clogged catcon...Symptoms are stumbling, rough/no idle, loss of speed, starts but won't stay running, stalling, etc...
Unbolt the 4 bolts on front of catcon (you have an '85, right?) and push rear exhaust off to the side, and start it up and see if this "cures" the problem...(Caution: the car will be loud)...
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