Sputtering and stuttering 03 sxt

Jerome Adams · Post by **Jerome Adams** » Mon Jul 02, 2012 5:34 pm

So my 03 SXT started to buck at low rpm (cruising thru parking lots and residential areas). When cruising on the highway I could feel a little stutter but only in a narrow rpm window. I figured it was the heat (less dense air) was giving the comp issues. I backed my cam timing off from +4 to +3 and it just shifted the rpm window.

Today I had about a 500 mile road trip and was trying to diagnose it the whole way. It only happened from 2500-3000 rpm at first. Then it started getting worse and it seemed like it might be tps as it was primarily when I was barely on the throttle. About 30 miles from home it started running real rough. I kept it around 4k rpm and it was okay. Then it started spitting and sputtering like it was running out of gas but only when under load (clutch in and it would idle fine). Then it started getting loud and almost sounded like a subie. Waiting for the engine to cool down and then will go mess with it. I already have another tps and map sensor from when I was troubleshooting a similar situation (the upstream o2 took a dump on me). I also have my old stock coil and wires from when I upgraded to Granatelli (the blue wires).

Hopefully it isnt more serious (internals). I dont want to have to pull the head again this summer (mag head, comp 400, mag intake all went on last summer)

Jerome Adams · Post by **Jerome Adams** » Tue Jul 03, 2012 10:18 am

swapped the wires and no change. Swapped the coil and it not much change if anything. Going to reset the PCM this morning and continue to mess with it. Will also try the TPS sensor. I see a lot of people having issues with the cam sensor, but I am not getting that code. Oh, well more digging today and see what I can find.

In other news my #4 spark plug has a threaded insert because the head had been previously repaired. When I pulled the plug the check them, the insert came out with the plug...and idea on how to fix that? SHould I loctite the insert back into the head and let it set before trying to remove the spark plug again?

Post by **occasional demons** » Tue Jul 03, 2012 12:18 pm

They sell on ebay solid inserts that you loc tite in place. Just have to use red, or it may not hold. A heli-coil usually won't back out, but depending on the insert used, IDK if a heli-coil will match the threads in the hole...

A border line CPS may give you poor performance, and not a CEL.

Fuzzyneon · Post by **Fuzzyneon** » Tue Jul 03, 2012 12:22 pm

occasional demons wrote:They sell on ebay solid inserts that you loc tite in place. Just have to use red, or it may not hold. A heli-coil usually won't back out, but depending on the insert used, IDK if a heli-coil will match the threads in the hole...

A border line CPS may give you poor performance, and not a CEL.

i was thinking cps to mine would show symptoms way before a cel

Jerome Adams · Post by **Jerome Adams** » Tue Jul 03, 2012 5:18 pm

Pulled the old stock coil and put the granatelli coil back on. Pulled the valve cover and verified that my mag cam springs are in fact mounted all willy nilly (not too worried about it). Valve cover was leaking a bit so i tightened and then over tightened it (snapped a bolt). Luckily it left a nice ridge so I could back the broken piece out with a flathead until it was far enough to grab with a needlenose. I had a few spare bolts in a old valve cover so that was an easy fix (luckily).

I swapped out the CPS and it seems to be good to go. Hopefully that was it and it wont come back. Original made it 113k so that is better than most.

As far as the repaired spark plug insert, I will try some red loctite, but not today...it is hot as hell and I have had a long day.

Jerome Adams · Post by **Jerome Adams** » Sat Jul 07, 2012 11:54 am

It is doing it again (stuttering at steady throttle below 4k rpm). Gonna swap tps today and see if that works.

I usually toss a bottle of lucas injecter cleaner in a few times a year, hoping it is not the injecters.

Wish the damn thing would throw a code so I know where to look. I also noticed the grommet for the iat looks like it should be replaced.

Post by **occasional demons** » Sat Jul 07, 2012 2:42 pm

The IAT wouldn't affect it.

If the IAT is after the filter, (CAI) then a new grommet would help seal out unfiltered air, if the air filter was dirty enough to create enough of a pressure difference that air would flow around the grommet.

I would bet on the TPS more than anything at this point.

Mine actually gave me a TPS/MAP correlation code, and I don't have NGC.

So I knew it was whack at that point.

If you have Speed Control, and it kicks out randomly, a bad TPS can cause that too. Well before it sets a code.

Check the exhaust before the upstream o2 for cracks/leaks too.

haseebgill12 · Post by **haseebgill12** » Tue Jul 17, 2012 10:45 am

Did the TPS fix it? I also have this issue.

Jerome Adams · Post by **Jerome Adams** » Sun Jul 22, 2012 11:36 pm

Nope, fresh set of plugs did though. Didn't think the plugs were that old but that was it