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Discussion Starter #1 (Edited)
i've done a complete tune up(plugs, wires, oil & air filter) and the OBDII reader is showing no codes. what i dont understand is how i'm still getting a mis/stutter in the engine when i rev it up w/o a load. ( i havn't had a chance to see how it is under a load as i'm still waiting for a MAFS to come in the mail. i used the one out of my 95 S/C.) GOD THIS IS FRUSTRATING!!!

any help/pointers/ideas would be great. i've gotta get the RED running and smogable again.

oh yeah, the search option took me about two hours to find out that as good as it is, well, 5 pages later there were absolutely zero posts about this.

please see gallery to see the 94 that i call 'ol Red, spanks.
 

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what do u have all done to the car? a leaky injector could cause this. a cracked coil pack too. did u check ur maf senor, some times they dont throw a code. try cleaning it and get back to us.
 

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u put 3.8 maf in a 4.6?
 

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Is it getting a good supply of clean fuel? Have you replaced the fuel filter? Are the injectors clean? Is the fuel fresh or has the vehicle been sitting for a long time?
 

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Discussion Starter #6
what do u have all done to the car? a leaky injector could cause this. a cracked coil pack too. did u check ur maf senor, some times they dont throw a code. try cleaning it and get back to us.
i cleaned the MAFS with the aresole cleaner thats labeled "mass air flow senser claener" and it did it's job well.

i was getting 0.01 volts from the C&D wires. when i put my S/Cs MAFS on it no codes showed. so that verified that i had a prob. with the MAFS.(before i was getting a P0102)

i changed the plugs, wires and a TPS that was showing 4.8 volts at idle (not a good sign)

i havn't replaced the fuel filter yet, but i've got one in the garage slated for my S/C, although i could use it for 'ol Red.

BTW it's a 94 LX w/a 4.6
 

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Discussion Starter #8
egr acting up?

UHHH. you know what i never thought of that. with the slightly high readings from the initial smog, it might be that it(the EGR valve) isn't opening, or it's fluttering.

I'll have to get another tool now(vacuum pump) and check it out.
 

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thats not a problem
how so?...if i'm not mistaken, the 3.8 mafs have a completely different transfer function from the 4.6 ones

also, the TPS should be showing less than 1V at idel
 

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how so?...if i'm not mistaken, the 3.8 mafs have a completely different transfer function from the 4.6 ones

also, the TPS should be showing less than 1V at idel
see thats what i thought to 3.8 maf are not calibrated for the 4.6 computers, only 3.8. different air fuel ratios, not to mention the 3.8 sc maf is set up to take in alot more air being supercharged and all. correct me if i'm wrong.
 

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here i got an idea unplug the maf and take it for a ride if the maf is causing the problem u will know right away because the car will run better
 

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Discussion Starter #12
here i got an idea unplug the maf and take it for a ride if the maf is causing the problem u will know right away because the car will run better

i definatly know that the MAFS is a problem. but with a good unit switched into it, it still has this mis as the RPMs rise.

the TPS was switched out also with a new unit since it was showing WOT voltage @ idle( almost 5V)

it's not those two items. it's gotta be somthing else.
 

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when your egr sticks open (or your dpfe sensor starts acting up) you wil have a "stutter or stumble" at idle AND wot...if your idle is ok im steering away from egr....im with fuel delivery.....such as fuel filter or fuel pump.
 

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Your not using Bosch Plugs with the tiny tip are you?

If not the only other thing I would do is check all your vacuum lines and wiring harness plugs for any corrosion.
 

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Discussion Starter #16
Your not using Bosch Plugs with the tiny tip are you?

If not the only other thing I would do is check all your vacuum lines and wiring harness plugs for any corrosion.
no, i havn't used bosch plugs since i got rid of my moostang GT. it loved boschs. autolites only now.

i'm going to have to go over this thing with a fine tooth comb. it just gets tireing
looking and looking and haveing no codes thrown by the comp(94 4.6 was the first year for the OBDII so it tells more than my 95 S/C), yet still stutters/misses as it revs.
 

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ok have u checked the fuel pressure and just for kicks gotten the alternator and battery checked out ??
 
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