tj wong?
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by 1uke
My L98 pops out the intake when the engine is warmed up,doesn't happen when the engine temp is cold?
I ran the codes and nothing comes up.
What should I look into?
I ran the codes and nothing comes up.
What should I look into?
Thread Starter
Advanced
Joined: Sep 2004
Posts: 59
Likes: 0
TJ,
Yes its firing up thru the intake.
Timing's set 6° initial ,tps works fine,once its warm it pops below 2200 when cracking the throttle hard in gear and in park.
This sets no codes at all.
Runs great after 2200 it'll turn 6000 like a clock pulls hard plugs look a little fat but not stone black sooty.
Installed a new set of plugs and get the same results.
Yes its firing up thru the intake.
Timing's set 6° initial ,tps works fine,once its warm it pops below 2200 when cracking the throttle hard in gear and in park.
This sets no codes at all.
Runs great after 2200 it'll turn 6000 like a clock pulls hard plugs look a little fat but not stone black sooty.
Installed a new set of plugs and get the same results.
Burning Brakes
Joined: Apr 2004
Posts: 1,034
Likes: 198
From: Atoka, TN
i had an 88 iroc that started popping/backfiring through the intake. it turned out to be the fuel pump. my fuel pressure was in the mid 20's. when i changed the pump, the popping when away. try checking your fuel pressure.
chris
chris
Racer
Joined: Aug 2002
Posts: 386
Likes: 0
From: Lancaster Lancashire
[QUOTE=1uke]TJ,
Yes its firing up thru the intake.
Runs great after 2200 it'll turn 6000 like a clock pulls hard plugs look a little fat but not stone black sooty.
[QUOTE]
Is this a standard L98 we're talking about here? If you are trying to turn 6000rpm on a regular basis, I would assume you may have one of the following:-
A weak or damaged valve spring,
A burn't intake valve
A maladjusted hydraulic tappet.
If it's a flat tappet cam, you may have a worn exhaust lobe, although that would probably show up symptoms all the time and would probably have a very noisy tappet.
A bad EGR valve may also give problems in the intake, but would probably throw a code.
I also assume you have set the ignition timing correctly by setting it with the EST wire behind the brake booster disconnected.
Dave
Yes its firing up thru the intake.
Runs great after 2200 it'll turn 6000 like a clock pulls hard plugs look a little fat but not stone black sooty.
[QUOTE]
Is this a standard L98 we're talking about here? If you are trying to turn 6000rpm on a regular basis, I would assume you may have one of the following:-
A weak or damaged valve spring,
A burn't intake valve
A maladjusted hydraulic tappet.
If it's a flat tappet cam, you may have a worn exhaust lobe, although that would probably show up symptoms all the time and would probably have a very noisy tappet.
A bad EGR valve may also give problems in the intake, but would probably throw a code.
I also assume you have set the ignition timing correctly by setting it with the EST wire behind the brake booster disconnected.
Dave
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by 1uke
TJ,
Yes its firing up thru the intake.
Timing's set 6° initial ,tps works fine,once its warm it pops below 2200 when cracking the throttle hard in gear and in park.
This sets no codes at all.
Runs great after 2200 it'll turn 6000 like a clock pulls hard plugs look a little fat but not stone black sooty.
Installed a new set of plugs and get the same results.
Yes its firing up thru the intake.
Timing's set 6° initial ,tps works fine,once its warm it pops below 2200 when cracking the throttle hard in gear and in park.
This sets no codes at all.
Runs great after 2200 it'll turn 6000 like a clock pulls hard plugs look a little fat but not stone black sooty.
Installed a new set of plugs and get the same results.
I have to assume that when you say "pop" its backfiring. There are only a few things that can cause that. One of them being a lean fuel situation. And in that case you need to double check the fuel pressure as one member mentioned. Another is an ignition problem. Check all your plug wires, and especially the cap where the coil resides. Make sure that the ground strap that goes to the center terminal is in place. I have seen too many people leave out that ground strap, all sorts of weird stuff happens when the coil ground is missing. Also check the cap for any burn through spots.
Thread Starter
Advanced
Joined: Sep 2004
Posts: 59
Likes: 0
its a hyd roller,fresh build,fuel press is good can go to 50 if needed its set around 38 or so.
I will check the ground strap a tight valve would keep missing with more rpm.
The car drive's normally with light throttle under 2200.
Mass air voltage is 1. volt at idle
I will check the ground strap a tight valve would keep missing with more rpm.
The car drive's normally with light throttle under 2200.
Mass air voltage is 1. volt at idle
Last edited by 1uke; May 8, 2005 at 04:06 PM.
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