runs perfect except pass 4k rpm

[iamshaked]

just bought a 95 gst, no mods anything 83k miles on it (btw typically if the car has been drove good how long do these engines/turbos last?)
anyway, they car runs great boosting good(first turbo'd vehicle)
but when i get on it and go past 4k rpm it seems like the car isnt accelerating as good as it should, almost like it doesnt want to go past 4k, but if i get on it in 1st gear it goes right past 4k without a problem, no clue.
also do i have to let the car sit for 30sec when im about to turn it off? i had a friend with a turbo'd paseo and he had a turbo timer i was just wondering if its better to let it sit and what is the exact purpose of that.
anyway going from a 91celica to this was just insane.
once you go turbo you'll never go back right?

 

[Livid]

Could be something as simple as replacing the spark plugs and wires... Yes, if you dont have a turbo timer leave your car running for at least 45 or so seconds before shutting it off. This allows the engine oil to circulate through the turbocharger bearing housing, drawing heat out of the bearings and impeller shaft to lower the temperature to a safe level. It would be a good idea to get a turbo timer though if you're planning on doing any turbo upgrades or higher boosting.

 

[gsxtacy]

Welcome to the DSM world. With that said, I would start with the simple stuff.

Check plugs, and regap them.
Fuel filter original?
Ever replaced/removed catalytic covertor?

ANY mods at all done to the car, or are we talking 100% stock?

Find another DSMer around you and get set up to do a piping pressure test.

The possibilites are endless till you can give some more specific info.

No, on the turbo timer issue, our turbos are water cooled. I do however recommend letting your car cool for a few extra seconds before you shut if off if your gonna park it after a 1-2-3 pull. Whenever you upgrade to a non-water cooled turbo, a turbo timer is nice for longevity of the upgraded turbo.



gsxtacy

 

[andymoraitis]

Could be something as simple as replacing the spark plugs and wires... Yes, if you dont have a turbo timer leave your car running for at least 45 or so seconds before shutting it off. This allows the engine oil to circulate through the turbocharger bearing housing, drawing heat out of the bearings and impeller shaft to lower the temperature to a safe level. It would be a good idea to get a turbo timer though if you're planning on doing any turbo upgrades or higher boosting.

Livid and did well in explaining what your problem could be and I'd like to add something to his posts. Of critical nature on these motors is not only a new set of plugs, but the use of standard copper plugs. Pull your plugs and check to see if they're platinum. If so, replace them. Well, replace them anyway with a set of NGK BPR6ES or Autolite 63's.

What you may be experiencing is an issue with plug gap. Under heavier load in higher gears, if the plug gap is too wide, the airflow can literlly blow out the spark on an intermittent basis and make the car feel sluggish or as if it's misfiring. When you install your new plugs make sure they are gapped to .026 to .028 for best results.

In addition, a boost leak will create the sense of power loss you may be feeling. Once again, this isn't apparent in first gear since the load on the motor is low. As gearing changes, more load is added and this where a boost leak would be the most apparent. Since you're new to owning a DSM, an excellent site for you to refer to would be the VFAQ which can be found here:

http://www.vfaq,com

Look under the "Intake" section and you'll find directions on how to construct a boost leak tester. Testing at least once every couple of weeks is recommended as simply looking at hose clamps doesn't tell you if you have a leak.

As far as longevity, maintenance is the key. A properly maintained 4G63 can run for more than 200K miles. Keep an eye on fluids and change your oil religiously and you'll have a long and happy relationship with your car. That, of course, goes out the window once you start making some real power, but for now enjoy it for what it is and make sure that she's well maintained.

Drop us a line with any questions and get some new plugs and wires in there. Welcome to the fold.

Andy

 

[andymoraitis]

Check plugs, and regap them.
Fuel filter original?
Ever replaced/removed catalytic covertor?

Good one. I got so busy being verbose that I didn't have a chance to hit the exhaust and fuel filter. Nice catch!

Andy

 

[Ultimatedsm]

just bought a 95 gst, no mods anything 83k miles on it (btw typically if the car has been drove good how long do these engines/turbos last?)
anyway, they car runs great boosting good(first turbo'd vehicle)
but when i get on it and go past 4k rpm it seems like the car isnt accelerating as good as it should, almost like it doesnt want to go past 4k, but if i get on it in 1st gear it goes right past 4k without a problem, no clue.
also do i have to let the car sit for 30sec when im about to turn it off? i had a friend with a turbo'd paseo and he had a turbo timer i was just wondering if its better to let it sit and what is the exact purpose of that.
anyway going from a 91celica to this was just insane.
once you go turbo you'll never go back right?

If you have a Multi-meter, test your coil pack and transistor. Check for resistance or OHM's, I recommend getting some kind of manual for your car.

What grade fuel do you use? Anotherthing I wanted to ask is to do a compression test to see if your rings are leaking any kind of boost.

1. BOOST LEAK TEST
2. Compression Test
3. Check plugs/wires replace if necessary (Gap your plugs .028)
4. Do a tune up in general if you haven't, which includes fuel filter, catalytic convertor (Check) etc.
5. Check your coil-pack/Power transister for resistance (These can cause funny power problems and people misdiagnose these all the time).

Check all those items out and come back with the conclusion.

 

[Livid]

No, on the turbo timer issue, our turbos are water cooled. I do however recommend letting your car cool for a few extra seconds before you shut if off if your gonna park it after a 1-2-3 pull. Whenever you upgrade to a non-water cooled turbo, a turbo timer is nice for longevity of the upgraded turbo.

gsxtacy

Yes you're correct. I'm a 420a 'er so I spoke too soon

 

[Ultimatedsm]

Remember don't forget to test your MAF as well, because mine was taking a crap on me and had the exact same problems. I checked everything and I was stomped, but it ended up being the stupid MAF.

 

[iamshaked]

Fuel filter original?
yup probably

Ever replaced/removed catalytic covertor?
im not sure last owner didnt mention it, so i assume everything is still original

ANY mods at all done to the car, or are we talking 100% stock?
Yes 100% stock



Ill pick some new plugs up tommarrow and see if that works and report back sometime

Remember don't forget to test your MAF as well, because mine was taking a crap on me and had the exact same problems. I checked everything and I was stomped, but it ended up being the stupid MAF.

how do i test my MAF?



also what would you recomend getting first Air fuel ratio guage or boost guage?

 

[talonTSIDriver]

Livid and did well in explaining what your problem could be and I'd like to add something to his posts. Of critical nature on these motors is not only a new set of plugs, but the use of standard copper plugs. Pull your plugs and check to see if they're platinum. If so, replace them. Well, replace them anyway with a set of NGK BPR6ES or Autolite 63's.

What you may be experiencing is an issue with plug gap. Under heavier load in higher gears, if the plug gap is too wide, the airflow can literlly blow out the spark on an intermittent basis and make the car feel sluggish or as if it's misfiring. When you install your new plugs make sure they are gapped to .026 to .028 for best results.

In addition, a boost leak will create the sense of power loss you may be feeling. Once again, this isn't apparent in first gear since the load on the motor is low. As gearing changes, more load is added and this where a boost leak would be the most apparent. Since you're new to owning a DSM, an excellent site for you to refer to would be the VFAQ which can be found here:

http://www.vfaq,com

Look under the "Intake" section and you'll find directions on how to construct a boost leak tester. Testing at least once every couple of weeks is recommended as simply looking at hose clamps doesn't tell you if you have a leak.

As far as longevity, maintenance is the key. A properly maintained 4G63 can run for more than 200K miles. Keep an eye on fluids and change your oil religiously and you'll have a long and happy relationship with your car. That, of course, goes out the window once you start making some real power, but for now enjoy it for what it is and make sure that she's well maintained.

Drop us a line with any questions and get some new plugs and wires in there. Welcome to the fold.

Andy

Just wanted to add another useful site: http://www.dsmsupport.com

 

[Mike Marnik]

Boost gauge! The a/f ratio gauge doesnt do a whole lot except fill the extra hole in your dual gage pillar pod and have some cool flashy lights. The a/f gauge is very inaccurate to do you any good tuning.

 

[iamshaked]

ok so today i changed the plugs to see if that was the cause of loss of power past 4k,
and it did not, but i did find a pool of oil in the 2nd cylinder where the spark plug goes (2nd reading from left to right).
i cleaned it out and i was sure that my problems would be fixed... cause why the hell would oil be there anyway?
so that kinda worries me.
im guessing now its a boost leak, but im still not totally sure.
frustrating

 

[will90Eclipse]

Was the oil in all the cylinders or just the 2nd Because it might be the gasket around your oil cap is bad, this would allow oil to get into your valve cover

 

[gsxtacy]

Did you gap them as we requested?

How do YOU install spark plugs? I usually use some needle nose pliers and gently set them down in the head and then I tighten them with the T handle/Socket.

Do a boost leak test.....Then if it persists..
Get your fuel filter changed next, then the cat updated/removed.

A dirty air filter can make inhaling/exhaling a chore too, take it out and clean the air box "really" well...now go for a quick drive and retest it, if your symptoms improve, you know your stocker Air Filter is pasted due too.

Without actually feeling YOUR car do this problem you are describing all I can do is tell you what I know may cause a problem like you are having.

A stock 2g doesn't really just tear it up after 4000 rpm either, its horribly restricted in nearly every area.


Best of luck,

gsxtacy

 

[iamshaked]

no i didnt gap them... i dont have the gap tool, does it really make a difference that i must gap them?
as for the install i just put the new plugs gently in, and then just tightend them as you normally would.
i have looked at the air filter and it does need replacing its really dirty on the bottom side, i shaked all the crap out of it for now, but i highly doubt this is why my car is acting the way it is. i do know a thing or two about cars so i know it "feels" wrong, i wish i had the money just to go and get everything fixed at once, but the car drained my funds so just gotta wait. also where the hell is the washer fluid? i have yet to find that..
also it seems like theres a mild highpitched tick comming from the spark plug wires where they plug into the dis cap, is that normal? im going to goto a shop today and see if i can get someone to take a look at it a bit more and go from there. ill repost when i return


Was the oil in all the cylinders or just the 2nd
just the 2nd one





update, no luck with the shops... everyone seems to be closed on saturday. but i did buy and install a boost guage.
reading 17-19 vacuum @ idle. im hitting about 12psi boosting seems normal right? (stock 10-15?)
ill monitor it while im at work tonight and maybe repost again, try to goto a hardware store and buy materials to build a boost leek tester