The 5K stutter cutout misfire stumble breakup Thread [Merged 7-8]

[Newlogics]

My project 92 Talon just wouldn't be nice to me.

I figured that my smoking problem was due to my turbo leaking oil, since upper IC pipe had whole bunch of oil in it.

Now more porblems arize....

1st: It wouldn't idle normally, instead it revs up to 2K and drops back to 1K every like 2 sec. if idle is adjusted to be lower then 1100 rpm

2nd: When rmp reach 5K under WOT, it hesitates violently. As soon as rpms drop a bit, it's fine again.

(The good thing I fix the unlock buttons, 'cause it had shaved handles and you couldn't get inside by any means except a trunk....)

 

[TrystanGST]

I'm sure this isn't your only problem, but the T-25 doesn't exactly shine after 5k....

 

[ArticNemesis]

I'm sure this isn't your only problem, but the T-25 doesn't exactly shine after 5k....

I was going to suggest the same thing.

 

[BoBbOrAzE]

yea thats very true but to me this definitely feels like a problem, before i had my uicp, maft, and bov it would still run fine all the way to 6.

 

[trevor_shiggs]

I had this problem yesterday. It was my BOV Dump Tube.

 

[BoBbOrAzE]

yes but i am venting properly with the gm maft so it can not be a dump tube. I am really hoping its and air to fuel ratio problem at high rpms and nothing else if that sounds right. Its driving me insane and i am still trying to upgrade my palm vx to os 3.5

 

[boostineclipse]

Car hits a wall evertime I reach that point. If I floor it.. just cruise up until that rpm point, anythin it always hits a wall. I have a 95 GST, with a 1G CAS, so I have swapped injector pins, and wires. A friend and I think its because I have the CAS Inverted option choosen on my Keydiver chip..

Anyone have experience with this? We are gonna take a look at it this sat, but I am bored and just wondering.

Have my SAFC2 settings at -%1 at 1K, then they gradually raise up to just -5%, but I don't think my settings are the problem. The chip is also programed for 650s. Fuel pressure is set to the base fp at 42.5..

Can't think of anything else that might be causing this problem besides a boost leak, but would that be so consistant at that exact rpm point everytime?

Appreciate any/all input.

 

[igopoopy]

fuel cut

 

[Defiant]

fuel cut

Unlikely. Fuel cut is purely a function of airflow, and there shouldn't be enough coming in at 4500 to trigger it.

 

[trbotaln]

sure sounds like fuel cut to me. Have you checked for boost leaks yet?

 

[Xit40]

I would definately check for boost leaks. Might as well check the easiest thing first and work from there. I was having the same sorta problem around 5K in 3rd gear pretty darn consistantly too. When I leak tested I found a bunch of leaks. After I sealed them up no more fuel cut. Scares the crap outta ya though.

 

[project_tsi]

im also going to vote boost leaks. they can cause your boost to creep too. can you feather the gas to gain more RPM's, like to 6k or so? Watch the boost guage to see if it creeps, by feathering the gas, it will keep the boost around 10psi or so, causing it not to get so much air, thus delaying the time that its "cuts" Its not genuin fuel cut, but its a type of fuel cut due to too much air when boosting.

 

[DSMTalonAWD51]

huge difference between boost leak and fuel cut, and id say fuel cut. Hes only at -5% on thw SAFC, I would get fuel cut back on the stock injectors even at 14psi sometimes if it was cold enough. Boost leak he would continue accelerating, if would just be way slow and stutter

 

[DSMTalonAWD51]

wait I just noticed he has a chip. Is your chip programmed to eliminate fuel cut??

 

[oldman]

huge difference between boost leak and fuel cut, and id say fuel cut. Hes only at -5% on thw SAFC, I would get fuel cut back on the stock injectors even at 14psi sometimes if it was cold enough. Boost leak he would continue accelerating, if would just be way slow and stutter

You're missing the point, they're saying a huge boost leak which will result in fuel cut.

 

[boostineclipse]

The Chip is programmed to get rid of fuel cut. I am gonna have it pressure tested this weekend. Soo.. I'll just recheck all my connections in the mean time, since I don't have access to a compressor.

 

[Stock92Talon]

When my timing was off 3 teeth it acted like I hit a wall @ 4500 RPMS. Just something else to check.

I almost didn't post this because it has nothing to do with what everyone else is saying.

 

[HighPsi92GST]

When my timing was off 3 teeth it acted like I hit a wall @ 4500 RPMS. Just something else to check.

I almost didn't post this because it has nothing to do with what everyone else is saying.

Did your car even run after that? Or was the "wall hitting" also your pistons smashing the valves?

 

[boostineclipse]

Ok.. here is the update...91TSiGuy was pretty damn close. So my friend and I get in the car after the CAS inversion re-program, still hits the wall. He looks over at my speedo.. sensor was not pluged in at the time. And says "wait.. your speedo don't work". And it both just hit us. Chip having a stutterbox, and with that.. getting the signal from the speedo sensor.. thought I was ALWAYS at 0mph.. or a stop.. so it would activate my box.. damnit.. .

 

[andymoraitis]

Ok.. here is the update...91TSiGuy was pretty damn close. So my friend and I get in the car after the CAS inversion re-program, still hits the wall. He looks over at my speedo.. sensor was not pluged in at the time. And says "wait.. your speedo don't work". And it both just hit us. Chip having a stutterbox, and with that.. getting the signal from the speedo sensor.. thought I was ALWAYS at 0mph.. or a stop.. so it would activate my box.. damnit.. .

I had the SAME thing happen to me and I thought it was something to do with the plug wires as well. Unfortunately, my speedo did work so it was likely the pulse generator and not the speed sensor. I had to have it removed from my chip, but it looks like you're good to go.

Good deal on finding it,

Andy

 

[Dream On]

I recently noticed my car is doing something funny. When going WOT, my car will rev to 5000 RPM's, then just sit at that RPM for about 2 or 3 seconds, then continue up the RPM band. I only have a K&N filter and just got done doing a lot of maintenance to the car, but no new plugs or wires for it (though when I pulled the plugs, they looked to be new, I've only had the car for 3 months or so..). It doesn't do it all the time though. I'm wondering if its just pulling timing or something since it has been kind of hot, and I haven't owned the car when its been cold outside. What do you guys think/suggest I replace/check? Thanks again!

 

[blackGSX2g]

What boost are you running?

I'd try doing a boost leak test first. See if you can borrow someones datalogger and see what your timing is different. If its starting to pull timing, your engine tone changes. Does yours sound a bit different when it hesitates?

 

[fwdturbobov1996]

Well id start with the simple things you didnt change.. plugs.

 

[Dream On]

Plugs look new. Car is stock besides the K&N, so stock boost. But the guy did say that he did the BCS mod, so maybe a little bit higher. Yeah the tone does change a bit, but its not that noticable. Hard to say I guess. I don't have any friends who are into these cars really, so its hard to borrow any parts from anybody. We'll see how it goes at night or when it cools down a little. I didn't notice it when I first had the car. I'll have to make a boost leak tester next time I'm home.

 

[fwdturbobov1996]

Plugs look new.. My ecu looks new, but does it work right. No

 

[GST with PSI]

Plugs look new.. My ecu looks new, but does it work right. No

that's the dumbest thing I've ever heard. the analogy you picked sucks. besides why would you reply and say something stupid that provides absolutely no helpful information to the question. not only did you waste space on this post but now i realize i must classify you in the same category as myself, a rookie member, a title shunned because of members like yourself. by the way nice gallery car pic. looks just like a 90 talon. you should probably review the photo gallery submission rules.

some helpful information you could have provided on a rookie level would have easily been:

check you base timing. the procedure is outlined in VFAQ under the engine category

your plugs look good which most likely means they are, however the gap you can't see with the naked eye. check you plug gap and adjust to specs.

boost leak test definitely. use a bottle of soapy water to help you find leaks you can't easily hear.

if you can get you hands on a vacuum gauge you can use in to tell you quite a bit about what's going on inside you motor. my Chilton's manual outlines a few procedures and explains a bit on how it works. a Chilton's or equivalent is a good tool to have.

a compression test wouldn't hurt. don't bother with a wet test, they aren't very accurate but if you find some problems after your dry test, do a cylinder leakdown test and that will tell you where your compression headed besides the cylinder.

buy a logger. it will tell you much more than anyone on this site. nobody can provide the info a logger can, but providing the people here with the your logger's info could tell others things it would take hours to type. and a 1g logger only costs about 140 bucks off ebay. (DEAL)

do those things and you may likely uncover your problem. hope this helps.