88 302 issues
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88 302 issues
I have a 88 302 FI that "surges" while idling, from 600 - 1300 or so and doesn't really smoothen out. It also died a lil while back and the smell of fuel was prevelent, so we ended up replacing the IAC sensor and it ran better for a couple weeks then it just died again with that fuel smell floating from under the hood.
Any suggestions?
Any suggestions?
Posting Guru
Joined: Nov 2004
Posts: 2,155
Likes: 1
From: sunny fla sometimes windy
What does it idle at with the iac wire disconnected? How are all the hard vacuum
lines? sometimes they get tiny hairline cracks on the radius and you can't hear it
but the effect of a hundred tiny cracks adds up. I would pull out the O2 sensor
and clean it with a propane torch, Hold it in the flame for 15 seconds wipe it off
and repeat untill the build up is thinned out and the vent holes are clear of any
build up. Don't use any spray cleaner!! Cleaning the Intake temp sensor could also
help the computer get clean signals. It is on the drivers side of the intake and
you should clean it with carb cleaner (takes a big deep well socket to remove)
Mine had a thick layer of gunk all over it and of course that slows it's ability to
read the incoming air temp. If both of these are dirty they can send corrupted
signals to the computer and after cleaning them you will need to reset the comp.
so it can rebuild the tables. Doing this is next to free and takes next to no time!!
lines? sometimes they get tiny hairline cracks on the radius and you can't hear it
but the effect of a hundred tiny cracks adds up. I would pull out the O2 sensor
and clean it with a propane torch, Hold it in the flame for 15 seconds wipe it off
and repeat untill the build up is thinned out and the vent holes are clear of any
build up. Don't use any spray cleaner!! Cleaning the Intake temp sensor could also
help the computer get clean signals. It is on the drivers side of the intake and
you should clean it with carb cleaner (takes a big deep well socket to remove)
Mine had a thick layer of gunk all over it and of course that slows it's ability to
read the incoming air temp. If both of these are dirty they can send corrupted
signals to the computer and after cleaning them you will need to reset the comp.
so it can rebuild the tables. Doing this is next to free and takes next to no time!!
New User
Joined: May 2007
Posts: 23
Likes: 0
check your egr valve too. my 88 302 was surging some too. i took the egr valve out and cleaned it the best i could. really helped with the surging. i dont think my 88 has a intake temperature sensor. ive never seen one anyways and have that intake assembly apart numerous times, the tubing anyways. havent check the manifold though.
Posting Guru
Joined: Nov 2004
Posts: 2,155
Likes: 1
From: sunny fla sometimes windy
Just disconnecting the battery!! Is your throttle position sensor wires roughly
pointing to the Idle air controller? What does it idle at with the IAC wires
disconnected? If soemone monkeyed with the hard throttle stop to turn up the
idle the computer thinks you are stepping on the gas and goes into the flooded
startup mode but of course you need to step on the pedal fully to complete the
procedure. Jross you have a IAT it is next to the knock sensor on the drivers
side of the intake it is a big 1 1/4 inch hex with a wire connector on it.
Edit I just thought have you pressed the valve on the fuel rail about a minute
after it has been running, If you had a injector stuck open after running it
would dump all the fuel in the rail on top of that cylinder. Start it up and with
a long screwdriver listen to each injector you should hear it clicking if one
or two sounds different or isn't making a noise you have a suspect. A heavy
dose of lucas injector cleaner (the whole big bottle!!) on a close to empty tank
and even taking off the filter and filling it full with it and just cranking a couple
rotataions to get the cleaner to sit on the rail may help.
pointing to the Idle air controller? What does it idle at with the IAC wires
disconnected? If soemone monkeyed with the hard throttle stop to turn up the
idle the computer thinks you are stepping on the gas and goes into the flooded
startup mode but of course you need to step on the pedal fully to complete the
procedure. Jross you have a IAT it is next to the knock sensor on the drivers
side of the intake it is a big 1 1/4 inch hex with a wire connector on it.
Edit I just thought have you pressed the valve on the fuel rail about a minute
after it has been running, If you had a injector stuck open after running it
would dump all the fuel in the rail on top of that cylinder. Start it up and with
a long screwdriver listen to each injector you should hear it clicking if one
or two sounds different or isn't making a noise you have a suspect. A heavy
dose of lucas injector cleaner (the whole big bottle!!) on a close to empty tank
and even taking off the filter and filling it full with it and just cranking a couple
rotataions to get the cleaner to sit on the rail may help.
Last edited by blue beast; Mar 6, 2008 at 05:22 PM. Reason: forgot a point
