no power over 4000rpm wtf

[hotlavaflow]

I pull good, good boost till 4000rpm exactly then the engine revs but there is no power what so ever. Out of gear it sounds fine but under load (in gear) it's a different story. Really annoying but from what I'm getting the general consensus is check the dizzy timing? I have to get this fixed asap.

By the way this a spare motor out of an auto 93 I dropped in while I build my original motor. I did drop it in without checking timing only because I didn't move anything and it seemed to be running fine in the auto. I'll do that first. I did change the spark plugs to colder plugs that's just about it and I don't have any leaks and my MAF is good.

Any other suggestions?

[codyace]

Does it rev above 4000? Or does it hit like a 'rev limit'

[ghettohatch]

funny story might have some relevance, when first got my car took it to a shop in vista i wont mention lol they forgot to hook up the vac line for my fpr!! instead the vac lines on the tb did a big loop. i drove off and felt just like what your describing, worth a check :P

[hotlavaflow]

Interesting..... I'll check that.

It revs above 4000rpm just no power it doesn't hit a rev limit.

[jarend]

my car is doing the same EXACT thing. hits 4000rpm's and it feels like the turbo stops boosting. my buddy says he thinks its the spark plugs. let me know if you figure it out. im changin my sparks today so ill get back to you on that.

[Bigsyke]

Pull codes, probably KS code.

[hotlavaflow]

my car is doing the same EXACT thing. hits 4000rpm's and it feels like the turbo stops boosting. my buddy says he thinks its the spark plugs. let me know if you figure it out. im changin my sparks today so ill get back to you on that.

I just put new colder plugs in I have to check the gap.

Pull codes, probably KS code.

Yeah pulling codes tomorrow.

[grey240sx]

same happen to my 240 but i changed the sparkplugs and it worked like a charm. good luck with that

[DataXUnknown]

I definetly recommend the NGK BK7RE sparkplugs if you haven't put them in already (on SR)...

[240sxxs]

I definetly recommend the NGK BK7RE sparkplugs if you haven't put them in already (on SR)...


quick question ..sorry not try to jack thread but ..bk7re does it come with iridium ??? cause some peoples said that when u buy iridium u dont have to gap them...is that true or u have to gap them nayway....im running SR right now..wll bk6re goood or recommended bk7re

[DataXUnknown]

The BKR7E's already come gapped and ready to go, never hurts to double check them though. I believe it comes with copper, not iridium. BK6RE is ok, just when you get ready to change them, throw in the BK7RE. I always trust the BK7RE's on SR's.

[codyace]

The BKR7E's already come gapped and ready to go, never hurts to double check them though. I believe it comes with copper, not iridium. BK6RE is ok, just when you get ready to change them, throw in the BK7RE. I always trust the BK7RE's on SR's.

You should always gap ANY plug you get, just to make sure. Get them to .022(higher boots cars) to .025 (stock cars) and you'll never have a boost blowout issue.

[mr.nixon]

happened to a friend of mine; no power after 4rpm all in all we ended up changing the fuel pump and it worked like a charm

[IMPORTIMAGE]

I pull good, good boost till 4000rpm exactly then the engine revs but there is no power what so ever. Out of gear it sounds fine but under load (in gear) it's a different story. Really annoying but from what I'm getting the general consensus is check the dizzy timing? I have to get this fixed asap.

By the way this a spare motor out of an auto 93 I dropped in while I build my original motor. I did drop it in without checking timing only because I didn't move anything and it seemed to be running fine in the auto. I'll do that first. I did change the spark plugs to colder plugs that's just about it and I don't have any leaks and my MAF is good.

Any other suggestions?

My friend's car did the same thing.

I know you said your MAF was good but try cleaning it and throttle body.

After we did that his car ran like a charm again.

Good luck!

[hotlavaflow]

I definetly recommend the NGK BK7RE sparkplugs if you haven't put them in already (on SR)...

Yep that's what I put in even though I'm KA-T. I'll try some regular plugs just to see but I'm leaning towards maybe my BOV is leaking. I'm going to swap it tomorrow with a new one off my other car and see what happens. I'll also clean the MAF and TB just to make sure.

I know this has been going on for a while but I've been too busy to really investigate this thoroughly. But I will def post up the results in case anyone else has a similar problem in the future.

Here's a vid of exactly what it sounds like. About 49 seconds in watch how when he hits 3500rpm it just gets raspy and loses all backbone, no power.

http://www.youtube.com/watch?v=z_LCifePIxg

[steve shadows]

Check the intake tube after the filter/maf, make sure if it is rubber it's not collapsing on itself as you're accelerating. This is a common thing that is overlooked on SR swaps and causes most of this type of issue on those setups.

Also what Engine Management are you running for your setup?

You say you are KAT, you will need an EMS to tune the car properly for boost etc. I hope you have this thing tuned otherwise you could be causing major damage to your motor and your motor may be pulling timing and going into limp mode due to having knock off the charts.

[om3ga]

MAF MAF baby dun dun dun dun duna dun dun


Yeah seriously check for vacuum leaks etc. Also the most important thing is to listen to what STEVE tells you. If you know everything in the world, he definitely knows more.

[Dru180sx]

I realy think you should check your fuel pump and fuel filter i see that your gas guage is under E and your probly clogging the filter with trash that sets at the bottom of the tank and also check your tps

[hotlavaflow]

The Vid isn't my car that's a clip of an SR I found that's doing the same thing.

steve shadows
My piping is all aluminum (except the MAF) so no collapsing. I checked for leaks after the MAF, nothing. I actually removed the piping and put it back on. Running a chipped ECU but I had this ECU for a while with no problems (like over a year). I swapped motors to fully build my original motor and this spare is a from a '93 Auto.

Dru180sx
New fuel filter, Walbro 255 pump and that's not my car my gas gauge doesn't go below half.

om3ga
checking the MAF this afternoon

The adjustment screw for the back of my HKS BOV was missing. I put a new one in and no help. I can hear the difference in the BOV closing faster but same issue. In the vid the guy said his BOV was leaking and causing the issue so today I'm swapping in the brand new one from my other car finally to test that theory.

I'll update this evening.

[rb26man]

NGK BK7RE ftw also check ur maf

[hotlavaflow]

Pressed past 4000rpm now since I tightened the bov. It's not perfect I still think there is a o-ring leak from the bov. It's running way rich though I need to recalibrate my WB just to make sure but it went down to 9.06:1 on WOT which is insane. Once I recalibrate I'll post the correct number.

I also think I need to balance my rotating assembly.

[steve shadows]

my car is doing the same EXACT thing. hits 4000rpm's and it feels like the turbo stops boosting. my buddy says he thinks its the spark plugs. let me know if you figure it out. im changin my sparks today so ill get back to you on that.

If you guys are talking sr or cars with rubber intake hoses please check your Intake Tube from the Turbo to the MAF. (turbo inlet tube).

If you're using the stock tube and it's missing the big metal spring inside it will collapse on itself under load, at about 4K rpms and will feel like you're hitting a wall.

People laughed when I posted a bulletin post on this topic about 1 year ago but It might be necessary to revisit this issue.

[hotlavaflow]

**Solution**

It was in fact the BOV that was leaking. After I tightened the BOV and installed a new o-ring it runs perfect. This is an older style HKS BOV.

steve shadows:
I'm going fully built in about 2 months. I already have all parts and I've started the machine work. Bore, deck, hone, p&p, 3angle everything. I don't want to rely on a chipped ecu alone for over 20psi daily. I'm thinking Nistune, what do you think? I have an AEM on my other car but I don't want to invest $1200 all over again. Especially if Nistune is $400 and seems be able to do basically the same thing.

[RYAN_S-14]

i was gonna say spark plugs, those AFR are really low im sure he fouls out plugs. Then you said its not your car in the video.

Thats cool you found the culprate