85 vette Running Rough
Thread Starter
Heel & Toe
Joined: Apr 2009
Posts: 23
Likes: 0
85 vette Running Rough
Hey guys first off the car acts like its not running on one cylinder and it surges when idling. Ive done a new fuel pump fuel filter cap rotor plugs and air filter and no diffrance. Its got 39psi of fuel pressure and holds it. Now on my #6 cylinder I can remove the spark plug wire and it dosent make a diffrance in how it runs so it must not be firing off. now I havent done a compersion test on it yet but I can hear it shoot out hear without the spark plug in the cylinder and the cars only got 101,xxx miles. And also when Im driving when I punch the gas the car will not move any faster it just stutters and acts like it wants to die but if im around 1/4 throttle its fine. I was thinkn I might have a clogged injector? Also this car has been setting for atleast 1 or 2 years so I was thinkn of using seafoam on it. Any help Would be great! also I have no check engine light. Oh 1 more question I put the acdelco #1 plugs in it and gapd them to .45 like napa told me but after I looked the chilton manual says .35 do I need to change it or is it no big deal.
Last edited by txwhitevette; Apr 16, 2009 at 03:58 PM.
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
Thread Starter
Heel & Toe
Joined: Apr 2009
Posts: 23
Likes: 0
This test is being done with the key just turned on not running. I put a new fuel filter in it and now it will only get up to around 32-33 psi? but it will hold and slowly start to drop after a few. Now I havent starded it scince the new filter im going to try a diffrent set of spark wires so there all up pluged right now.
Last edited by txwhitevette; Apr 16, 2009 at 09:38 PM.
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Thread Starter
Heel & Toe
Joined: Apr 2009
Posts: 23
Likes: 0
Ok I got one of the injectors to unclog up and it is idling smoother but is even worse about giving it gas and it stutters even more and at idel. Now after the car warms up the fuel psi drops to dang neer 20 psi and when you kill the motor the psi acctualy climbs back up?? Now when the motor is cold it acctualy runs alot better cuz the cold start injector I susspose.
Racer
Joined: Jul 2008
Posts: 272
Likes: 0
From: LA
I just went through the same issues with my 85 this last year. Here's the list of items replaced. Each one caused a noticable improvement in either idle, power or fuel economy. This list is in order of replacement.
fuel filter
fuel pump
air plenum gaskets, all sensors in the air plenum
AIC and TPI
knock sensor
fuel injectors (after market)
fuel pressure regulator (adjustable)
MAF (and thermostat)
one fuel injector plug
This was done over a three month period of time. I finally got a good idle, lots of power and good fuel economy.
Good luck and keep at it.
fuel filter
fuel pump
air plenum gaskets, all sensors in the air plenum
AIC and TPI
knock sensor
fuel injectors (after market)
fuel pressure regulator (adjustable)
MAF (and thermostat)
one fuel injector plug
This was done over a three month period of time. I finally got a good idle, lots of power and good fuel economy.
Good luck and keep at it.
Thread Starter
Heel & Toe
Joined: Apr 2009
Posts: 23
Likes: 0
If the pressure regulator is bad will it cause the fp to go from 40 to 20 psi in a matter of minutes while idling and when you kil the motor it jump back up to 30psi just setting there?I know why it wont run worth a dang becuase the fp is low but it is idling good it just wont pull out when you push the trottle.
Edit: Ok after letting it set for a few min I pulled the vaccum line off the regulator and a bunch of air and fuel went bursting out is it susspose to do that?
Edit: Ok after letting it set for a few min I pulled the vaccum line off the regulator and a bunch of air and fuel went bursting out is it susspose to do that?
Last edited by txwhitevette; Apr 20, 2009 at 04:55 PM.
Safety Car
Joined: Jun 2006
Posts: 3,611
Likes: 100
From: Palm Springs,Ca.
2020 C6 of the Year Finalist - Unmodified
I have a miss as well, have done the following:FIC Injectors- Bosch III
plugs
wires
cap
rotor
coil
fuel filter
compression test (180 across)
ohm'ed new injectors pretty much 15 across
wires ohm'ed all good.
Just a steady miss....
I don't know what else to do, so if you figure it let me know and vise versa.
Last edited by jdurhan; Apr 20, 2009 at 05:16 PM.
Le Mans Master
Joined: May 2007
Posts: 8,448
Likes: 27
From: Valparaiso
i was misfiring,swapped injectors and misfire is gone !
you might want to contact Jon !
Hi tx,there is no wrong way,there is no other way than Jon at FICINJECTORS.-
Check them out here
http://www.fuelinjectorconnection.com
SEND FICINJECTORS A PM HERE
If you want to read feedback on FICINJECTORS CLICK HERE
i have dealt with them several times and im very grateful to them
so that's why i recommend them so much,you know what
i live in Southamerica,and this guy (Jon) called me at his own expense,to assist me LIVE on my injector installation...
what can i say about that ?
that's class act man,that's class,he worries about every one and each one of our car's injectors !
Now that's customer service!
you might want to contact Jon !
Hi tx,there is no wrong way,there is no other way than Jon at FICINJECTORS.-
Check them out here
http://www.fuelinjectorconnection.com
SEND FICINJECTORS A PM HERE
If you want to read feedback on FICINJECTORS CLICK HERE
i have dealt with them several times and im very grateful to them
so that's why i recommend them so much,you know what
i live in Southamerica,and this guy (Jon) called me at his own expense,to assist me LIVE on my injector installation...
what can i say about that ?
that's class act man,that's class,he worries about every one and each one of our car's injectors !
Now that's customer service!
Thread Starter
Heel & Toe
Joined: Apr 2009
Posts: 23
Likes: 0
Yep after talking to a ase tech from around the area he agreeg fuel shoudnt brst out of rhar vaccum line when you pull it off and of course the line smells like gas and Ive herd if it does then its bad. This also explains why my fp is flucting so much. Oh and btw the injectors are ok i got them to where they click like they should.