The Top Mitsubishi Galant VR-4 Resource

Join the best E39A 1991-1992 Mitsubishi Galant VR-4 community and document your GVR4 journey.

  • Software Upgraded - Reset Your Password to Login
    In order to log in after the forum software change, you need to reset your password. If you don't have access to the email address you used to register your GVR4.org account, you won't be able to reset your password. In that case, follow the instructions here to regain access to the forum.

New Problem No Pull after 3,000 RPMs

Hey everybody I have finally got my car running again after multiple issues but now it isn't running well. The mods on the car currently are ets fmic, big 16g, 650cc fuel injectors, 3g mas, Apexi Neo AFC controller, and a keydiver chip for all of the mods. The car will pull quickly up to 3,000 rpms and the boost will be at 15 lbs but then the car will slowly make its way up to the higher rpms. It does not hit fuel cut like it was before I had the chip and injectors. It just feels sluggish and will not move quickly any suggestions about what the problem may be will be very helpful. I know our cars do not always like the Neo AFC controller so could that be it, although the car runs better with the AFC than without it on the ECU alone? I feel like I am so close and I am just missing something simple.
 

Well I have not changed anything since I did the last boost leak test but just for the hell of it I went and tested it again. No air leaks but I could hear what sounded like bubbling within the block. Does this mean a bad head gasket?
 
Last edited by a moderator:

CarRacer

Well-known member
Joined
Jun 28, 2007
Messages
4,371
Location
Shakopee, MN
That sounds like bad turbo seals. Are you noticing any smoke from the exhaust under acceleration?
 

There is no smoke coming from the tailpipe, the turbo was used when I had it installed so maybe it was bad from the start but the shop that installed it said it was good. Any other suggestions?
 

CarRacer

Well-known member
Joined
Jun 28, 2007
Messages
4,371
Location
Shakopee, MN
How's the oil look? Does it look milky? If it does the head gasket is toast and your oil and water are intermixing.
 

I just don't get this, oil looks good no milky coloration. I don't know how much more confusing this can get. I am tempted to start all over with a completely new engine or just sell the car as is.
 

1990ggsxnj

Well-known member
Joined
Nov 21, 2008
Messages
525
Location
Blackwood, NJ
A boost leak test at the turbo inlet won't show a vacuum leak pre-turbo. If you DO have one, you could be running lean which would cause the loss in power. If it only leaks after a certain HG of vacuum from the turbo/engine, that could explain why the drop after 3k. Have you checked all of your clamps and couplers? Do you have a wideband or narrowband 02? What's the reading? Getting any knock? What PSI did you get up to when doing the tests?
 
Last edited:

mikus

Well-known member
Joined
Jan 11, 2007
Messages
2,763
Location
Aurora IL
be cool man, there's a solution, and it's probably not a huge deal. (But don't let boost spike again, that can be disasterous)

Forget the bubbling for now. It *could* be turbo seal on the way out, or not - sometimes they don't seal well on a cold motor w/ no oil - not your main problem now.

Does it run perfectly otherwise, or are you bogging down, stuttering, slipping clutch, rough idle? When you make boost do you get ANY power, or just a boost gauge showing off? What was the full detailed running condition before you put that IC on?

I'd be looking at these...
- ignition
- check timing and maybe compression test just to be sure everything is in order
- wastegate - is it sitting slightly open or opening early?
- sensors: TPS, MAF, O2, ECT (have a logger?)
- long shot, drop your downpipe and see what happens
 

1990ggsxnj

Well-known member
Joined
Nov 21, 2008
Messages
525
Location
Blackwood, NJ
Quoting IbanezIC300:
boost will be at 15 lbs but then the car will slowly make its way up to the higher rpms


Pretty sure this rules out slipping clutch, but definitely check the rest (esp Logger).
 
Last edited:

Alright to explain some more on the car I have a wideband on it and when have made sure that the car does not run lean at any point. Also I do not believe the boost has "spiked" at any point since my gauge has never read over 15 lbs. The car runs pretty well and will sit and idle just fine, then take off and get up to 3,000 rpms it goes quickly and easily and feels like it has plenty of power. I am pretty sure this has to do something with the turbo since I am showing full boost at 3,000 rpms. My car did run well before the install of the intercooler and well after. The car started to overheat but this was found to be due to the fan which stopped working. The car now has two fans and will not go anywhere past halfway on the gauge when warm. After this the car was taken to a shop for all of its mods and came back running slower and more sluggish than it was before the mods. This is when I decided to get the keydiver chip and 3g MAS to compensate for the modifications. These last two things have helped the car to run a little better than before. The car did not run too well with just the chip and ran better after I started using the AFC.

- What could be wrong with the ignition if the car sits and idles well and will rev up while sitting?
- The compression was checked and was good.
- The wastegate is an interesting idea and I will have to look into it.
- I am not sure about the sensors and I do not have a logger.

I think this situation is just confusing since I am new to these cars and do not have much experience with turbo cars.
 

Like Hertz said for the third time, do a boost leak test. Also check your base timing, it almost sounds like the timing is being pulled. Have you logged it to see if your getting knock?
 

Ok as I said after the first time someone suggested a boost leak I did the test and there were no sounds of air leaking anywhere in any of my intercooler pipes but I could hear a bubbling sound from within the engine this is why I asked what that could mean? I agree that this certainly looks like a boost leak since the turbo is spinning up to full boost way too early.
 

jared50438

Well-known member
Joined
Oct 6, 2008
Messages
106
Location
garner,ia
where are you testing from? pull your intake tube off and pressurize from the turbo inlet so you can test for leaks all the way to the tb.
 

mikus

Well-known member
Joined
Jan 11, 2007
Messages
2,763
Location
Aurora IL
a boost leak will cause an increase not a decrease in spool-up time - pressure builds faster in a closed system.

the bubbling is most likely air slipping past a turbo seal. Don't freak out about this - turbo seals sometimes don't seal perfectly without oil and heat, if you're not blowing oil/smoke when running you're probably fine. It's much like shaft play, a bone dry journal turbo typically shows lots more shaftplay than an oiled one.
 

I have been testing from the the turbo inlet so that pressure is built from there all the way through the piping and I can not hear anything and it holds the pressure. I had a boost leak before when the FMIC was first installed and it was easy to locate and fix. This time I have tried placing my hand around the clamps and hoses to listen for changes in sound but I have not found anything.
 

NateCrisman

Well-known member
Joined
Nov 22, 2008
Messages
2,054
Location
Blairstown, NJ
Check your cam timing, a timing belt that has slipped one tooth can do this: good low end power, early spool up, and dog poop top end
 
Support Vendors who Support the GVR-4 Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications RixRacing RockAuto RTM Racing STM Tuned

Recent Forum Posts

Top