2G Loss of power on heavy acceleration!! ### help

[LongJonSilver]

Alright I've searched and seen this problem before but I think mines unique. Im a bit new to the DSM world. So heres my problem, when i floor it my car will pull hard up to 4K/4500 mabe then will "hit a brick wall" and i hear loud popping sounds the rpms won't go any higher. However, if im halfway on the acceleratior i can go 7K+ in every gear. Now my car has no rev limiter and i have a evo8 fuel pump w/rewire kit (+supportin mods of course) now what could be my problem? I checked my pulgs/wires and theyre good and im almost 100% sure no boost leak because it will hold boost to whatever I set it to (15psi now). please help...

btw. full car specs are on my profile

Thanks

 

[6bolt_tsi]

Alright I've searched and seen this problem before but I think mines unique. Im a bit new to the DSM world. So heres my problem, when i floor it my car will pull hard up to 4K/4500 mabe then will "hit a brick wall" and i hear loud popping sounds the rpms won't go any higher. However, if im halfway on the acceleratior i can go 7K+ in every gear. Now my car has no rev limiter and i have a evo8 fuel pump w/rewire kit (+supportin mods of course) now what could be my problem? I checked my pulgs/wires and theyre good and im almost 100% sure no boost leak because it will hold boost to whatever I set it to (15psi now). please help...

btw. full car specs are on my profile

Thanks

I wonder if the RPM signal wire on the CAS has an issue. You should try swapping out your CAS.

 

[ndsti]

Well.... your problem is that you may have the supporting mods, but not the right ones!

You profile shows that you are using stock injectors, correct?

You also have no way of tuning your new parts, no SAFC or anything!

To solve your problem, you are more than likely seeing fuel cut! This is caused by the mass air flow sensor seeing to much air for what the injectors can handle, so it cuts out the fuel!

Read up on Fuel Cut.

 

[LongJonSilver]

im pretty sure they're aftermarket injectors(different connectors?). Im not really sure i bought the car a little while ago. and yea no safc

 

[ndsti]

Do they have anything written on them, most injectors have something on them to identify them from others of the same brand?

I would put money on that you are hitting fuel cut!

You also are probably running really really rich, which also can lead to fuel cut. Another problem is that if your injectors hit 100% duty cycle then you could see fuel cut.

I HIGHLY SUGGEST that you go out and buy a logger and a SAFC, they are two key items that you MUST have for the mods that you list!

 

[LongJonSilver]

hmm ill check the injectors out tomorrow. And what is "100% duty cycle" mean? Also, i was thinking to just wait a bit longer and buy dsmlink instead of buying the logger and SAFC is there any difference (between using a real logger+SAFC vs dsmlink to log/tune a/f)?

also could it be my spark plug gap. I remember checking them and it was a little big like .031/2 or something? Its a continous popping/backfire noise

 

[thiazole]

DSMLink is much better than an SAFC. An SAFC is a very crude device compared to DSMLink.

I actually suspect it is spark blowout and would be remedied with a tighter gap (try 0.026" gap and see if it clears up). That being said, you really need to figure your injectors out. If you are running aftermarket injectors without any kind of fuel management, then you are running pig rich and will have lots of other problems. Otherwise you are running the stock injectors and are at risk of damaging your engine from a lean condition.

 

[ndsti]

100% duty cycle means that the injectors are running at 100% capacity, which can cause a super lean condition or a super rich condition depending on how your car is setup.

If you don't want to spend $700+ on DSMlink look into ECU+. They are not being sold any more but the support is still their, MACHV might still have a few left.

You can try to regap your spark plugs but I don't think that will solve you whole problem.

You will also need to buy a wideband air/fuel system to accurately monitor A/F.

Search the forums for DSMlink many people have different opinions on it. You also need to make a list of what your goals are. PM me if you have any questions!

 

[LongJonSilver]

alright kool thanks. I'm going to try a few of these things asap. hopefully my prob will be fixd soon ill let u kno

 

[carfan2000]

I agree with the feedback you've gotten so far, but I'm curious on how you checked you plug wires? It can be difficult to see any imperfections (I know from experience). I had a similar issue and it turned out to be the Magnecor wires (see link below). Anyway, if you haven't tried using a set of OEM plug wires... I would. It worked for me. Good luck.

Magnecor Race Wires: Mitsubishi twin cam technical bulletin

 

[LongJonSilver]

basicly to check the plugs i took them out and none were black/had any dark color. Then i used the "gap checker" tool and i think it said .35in (or what ever unit thats in) so it was bit large. I'm going to check the wires too i guess they wernt black either. Just waiting for a friend to let me use his wires.

 

[jking29]

Have you done a boost leak test? Just because you can hit a certain level of boost doesn't mean you don't have a boost leak.

 

[LongJonSilver]

I have re-gaped my plugs to .28 they were at .35 but that did nothing now tomorrow after work i'll do a boost leak test. Also today after i parked my car i noticed on the right front part of my car coolent fluid was spewing out...my temp was fine tho so idk why? mabe came out of the dump tube? nothing seemed poped or broken or anything. then later on my check engine light came on but i think thats from my O2 i kinda hav a cat but parts r slowly being blown off maby thats why. I'll have to look up the proper way to do a boost leak test but I'll post results tomorrow.

ps. can a evo 8 rewired supply enough fuel to my car? I was thinking the pump was cutting out

 

[jking29]

mabe came out of the dump tube? nothing seemed poped or broken or anything. then later on my check engine light came on but i think thats from my O2 i kinda hav a cat but parts r slowly being blown off maby thats why.

Huh? WTF Please try and use correct grammar and spelling so we can try and understand and help you. Ok, so if I understand correctly you are pushing coolant, and you have a cel. If you are pushing coolant, first thing check to see if you have coolant in the oil. It will look a little like chocolate milk if there is. Also look to see if you can see oil floating on top of the coolant. Next I would run a compression test. You also need to find out exactly why it is throwing a cel. As far as the Evo pump, it will be plenty capable of feeding enough fuel to max out the 16g.

 

[LongJonSilver]

Finally I have done a boost leak test . I had 3 leaks. One at the boost controler, one at the intake coupler and one at the intercooler inlet coupler. Ive taken apart the whole intake/intercooler piping and retightened everything. However when I tried to retest the system I broke my tester so I had to wait till the glue dried again. So ill be doing another boost leak test on friday after work. I drove the car it feels a bit better but still cuts out at 4500. I also found i have the stock injectors and Im trying to locate a cheap EPROM ecu. Im just pretty broke at the moment.

 

[LongJonSilver]

ok just bought a second eprom and installed it. With the EPROM in im still geting cut @ 5000 makes no sense? Any sugestions?

ps. after i installed the eprom my check engine light isn't on anymore

 

[r1991_4g63t]

its been suggested many times, you need bigger injectors and something to control them

 

[saechao04]

I agree, bigger injectors and something to tune it with. I have stock injectors and fuel pump but have a FP BT28, I do have an SAFC but no logger yet and no wideband. I got fuel cut once but I didn't want to damage anything so I only drive it when I have too, and never hit boost when I do drive it. It sucks but do yourself a favor and get injectors and something to tune it right with.

 

[LongJonSilver]

yea im in the market 4 680s rite now mabe 720s if I find them cheap enough and I already have DSMlink just don't have the eprom socketed yet. AFter it gets socketed I'll be using my new injectors adn the dsmlink. do i need a new fpr?

 

[ndsti]

Does the car have the stock FPR still. If so they yes I would highly suggest you get an FPR.

 

[LongJonSilver]

ok i got 750s installed and the eprom still got fuel cut....i tried a friend's eprom with a TMO chip and still fuel cut... I still have the stock fpr im going to try swaping that out mabe later today. So i still cut out at 5k rpms with bigger injectors and different ecu's. I read a long time ago that 97 gst's have a governor in it. I have a gst converted to GSX.

 

[sniperelite]

Well i would say just try a new set of the correct plugs just to be sure its not the plugs. Also, I was having this exact same problem as you with hitting a brick wall, but being able to go through the rpm's all the way to 7k when i did 1/2 throttle. It turned out that I had some random spark plugs in there I did not know about that was causing some of the problems, but also, my fuel injectors were missing some of the spacers and weren't seated correctly, so I was losing fuel. Check those things to make sure you have all the spacers for your injector and check the injector seals as well.

 

[kiwidog]

When your car cuts off at 5K does it just hit the wall and stay there or does it only do it for a couple seconds and goes away? Pretty much can you let off the throttle when quick when it hits the wall and then get back on it and it will rev fine or will hit hit the wall again?

 

[->PrOjEcTGS<-]

I'm going to guess that you do have a boost leak. You said you "assume" there are no leaks. How do you know? Have you pressurized the system so that you can see where your leaks are? Every turbo car I have owned has ended up with leaks here and there throughout the system. It just comes naturally with turbo cars. Go to home depot and create a boost leak tester. Then you will know for sure if you do/don't have any leaks.

If you have a major boost leak your boost controller will keep your turbo pushing out 15psi. But here's the problem, if you have a leak, your MAS is registering all that air that the turbo is sucking in and if you lose some of it due to a leak your ECU doesn't know. The ECU will think you are flowing an unsafe amount and is programmed to shut down aka "Fuel Cut" before you lose the motor.

 

[LongJonSilver]

I hav NGK7s @ .28, I have 100% no boost leaks i just tested it(fixed them all), i just put the injectors/spacers in and am not loosing gas