So,my car is hitting fuel cut....I think.its fairly violent and only happens when I’m in the throttle fairly heavy and stay in it.at this point the car is a banshee...then pow,it falls flat if I come right back into it it comes right back on.i bought this car(1987 325 convertible)with mods already installed so now I’m trying to learn about them.it has an open compressor intake.would the addition of an air cleaner restrict air flow enough to stop the dreaded fuel cut?
Or if that won’t work I thought maybe just put a lighter spring in my waste gate?i don’t trust the gauge so I’m not exactly sure how much boost it’s making but I will say this..it’s plenty strong enough for me.then I could drive harder which would make me happier.anybody think this could be a viable solution?
Nobody can help you if you don’t give any relevant information. I saw in your other thread that you said it has a megasquirt 2 in it. Download Tuner Studio MS, which is the software you need to connect to the megasquirt. Get it connected to a laptop with a serial cable. This software will also let you record a datalog. If you start recording a datalog and go take it for a drive and make it cut out we will be able to see on the log if it is overboost cut or something else.
Under the boost control menu you will find a setting for overboost protection. This is the setting that shuts the engine off when boost goes too high. You can change the setting or turn it off, but there is probably a reason that it’s overboosting now when it wasn’t before. Most likely cause is the hose going from the turbo to the bottom port of the wastegate has come off or is leaking. You’ll need to fix whatever went wrong with the wastegate or it will never work.
Last edited by someguy2800; 01-03-2019 at 10:07 PM.
I’m trying to give all the info I have.i thought maybe I needed to get these issues worked out before I brought it to a tuner.im not sure if it has been doing this cause I just got the car.im trying to get to a point I can safely make a couple hits for a tuner.as of now I can’t open her up except for a couple seconds.im a millwright.i work on power generating steam turbines but I have very little experience with cars.dont know if the turbo is too big or not I’m just trying to get it running good enough to hit redline so we can get a baseline.?.i really need to be guided through this so I don’t hurt the car before it’s running safely.as far as hooking it up to laptop and using software....forget it I’ll have to pay someone else cause I’m clueless!sorry but that’s about the truth of it
do you have a laptop?
at least some info on the car damn.
No(embarassed),I don’t even have one....if I can get access then what?download studio?can a techno moron figure it out to get some basic numbers?will it make corrections automatically?and give some kind of diagnostic report?...I feel like an idiot
Info is 2.5 325 with aftermarket coil system,42 lb injectors,forged motor.arp studs,lowered compression,gt35-t70 turbo,inter cooled, car idles rough when cold,pulls hard till it hits cut.it does it at heavy throttle,tell me how to get started
https://www.diyautotune.com/support/
Start reading!
It all depends on what settings were put in the computer by the previous owner. It is capable of self corrections to the fuel table but I don’t know if the previous owner enabled that or not. There is no self diagnostics.
As I stated above though the first thing to check is the wastegate which is mechanical not electrical. The symptoms you describe sounds like the pressure line going to the bottom port of the wastegate has come off or is damaged. Check that out first. Google how a wastegate works to start getting some familiarity with the system. Until the wastegate works properly there is nothing else you can do to the car to fix this.
If the wastegate is functioning mechanically the best resource to figure out the computer settings is probably the previous owner, even if you have to pay them. If they built it they should know how it ticks.
- - - Updated - - -
Oh, and what motor is in the car, m20 or m50?
Thanks... I will be delving into it further today....should get new valve cover gasket today.i will do valve clearance adjustment and oil change.i read somewhere they should be set at .008 to.010” with cam turned up for each one.i will look to verify this clearance but does that sound about right?i wasn’t sure if that should be set differently cause of the turbo or stick with stock clearance recommendation?...thanks a lot...and I will clean and verify waste gate functionality.also check every single hose coupling for boost leaks
bro what engine do you hhaaavee?
just google how to adjust valves on m20.
did it drive fine and started doing this when u bought it?
100% it's going to be the wastegate line go check it out right now. takes 2 minutes.
the boost gauge you say you do not trust this. Why?
is it way higher then it was? maybe that's exactly the reason.
I took the electronic boost control out of the loop and it seems to have eliminated the fuel cut.yes!boost is lowered quite a bit.maybe they just had it cranked up too much?maybe try a manual controller?turbosmart has that switchable dual stage.set one mild and ease up on the other till I hit cut then back it off a little?...maybe I just need to go to dyno tuner now that I can open it up.?
I think you need to get a $100 laptop and download the software and start familiarizing yourself with it. A Dell D800 off ebay would do nicely.
96 M3, GT4094R, Arrow Rods, CP Pistons, Elring HG, cutring 87mm, 10 mm ARP studs,MS3pro, EMC Intercooler, n54 6 speed with Motiv twin disk, ZT-2 wideband, Zionsville Radiator, X-brace, H&R springs with bilstien shocks, QTP electronic cutout, Line Locks, stock exhaust 455rwtq, 453rwhp at 14 psi 91 octane.......684rwtq, 681rwhp at 24 psi running flex fuel E60 at time of dyno tune.
Bookmarks