hey all, i was wondering if any1 had experienced this problem or had sum advice for a not so knowledgable guy to grand nationals.
welp i have a stock 85 GN with 62K on it, and when my car is in idle, it runs very rough.
i changed the the wires and plugs and checked my vacuum lines.
I don't know where to start looking.
plus my car runs good, but when i really put the pedal down on my car it has a really loud, spark knock, or i am assuming thats whut it is.
i run nuthing less that 93 in my car, and never let it go under 7 gallons
so i dont think it is bad gas.
i dunno if the car could possibly be out of time or sumthing or the car might not be gettin enogh car or what.
i dont know 2 much bout these cars just yet
welp maybe sum people could give me a some advice
i woudl appreciate it greatly
thanx for your time
brian
xxninja@aol.com
Ive got something of the same problem??? Any advice anyone???
Myself as well. THis is my first post - just bought an 87 GN with 12K Original miles on it. Supposedly 100% stock. My car seems like it has a misfire during idle and going about 45mph in OD. Giving it slight throttle makes it hesitate. Kind of like a feeling that during slight constant acceleration in OD or Drive sometimes, the car starts accelerating smoothly, then hesitates, and accelerates a little more, then hesitates..
I can actually see the MPH gague dip-down an mph or so when it does it, then start climbing again. Idle is like i have a monster cam in it..the car shakes, and will sometimes "pop" if i nail the gas off idle. This cant be normal for a car this "new". It's only been driven about 1500 miles in the past 3 years..only a sunny-day car, but this is now my daily driver.
Please help! I know absolutely NOTHING about these GN's. I was a V8-guy ;) I have no scan tool or anything - just picked it up yesterday. Normal driving is fine..car doesn't seem to hesitate at all except when RPM's are really low, or the engine is loaded-down at idle, or when accelerating in OD. I was going to replace plugs, wires - but dont want to if any experts here think it could be something different. I dont want to spend $500 guessing what the prob is.
Any help GREATLY appreciated!
Thanks
Guys, welcome to the "dark side." First off I would do the "Spring Cleaning" to your cars. Just because your cars may only have small amounts of mileage on them, they are still 15+ years old and things wear out over time. Some things wear out faster when not used, like very low total mileage or only a few hundred miles a year. I would HIGHLY recommend a scan tool. I went for a few years without one and really wish I would have gotten one sooner, it usually takes a nice amount of guess work out of troubleshooting problems. They aren't that expensive and they are something you can use everyday if you want. But you'll definitely use it once you get it and it won't sit around collecting dust. Especially after you get into trying to make it faster, then they are invaluable. Go through the spring cleaning and then see if your problems change. It's something everyone does or is a damn good idea to do every spring for these cars, hence the "spring" in the name.
Good luck
If you are new to this web site the spring cleaning articles are in... the resources pull down tab.... then the technical info... then the 1st artical is the 1 ya want good luck!!! its not as bad as it may seem once ya get to know your car! have fun! eric smith
Well - after countless hours of researching these forums I decided to start replacing the small stuff...fuel pressure regulator, o2 sensor, MAF sensor, plugs, wires, coil, TPS voltage regulator, K&N...after all that - still had the same problem. I ran consistent 14.20 in 100% 1987 original trim, and 14.00 after those mods. I though "okay..it has a few quirks, but it's obviously running consistently faster than 14.30, so i can start modifying it i guess" ...my ultimate goal is a consistent 12.50 car that i can drive daily, and take across country on road trips on a whim without needing to throw a toolbox in the trunk ;)
Since the car was running better than 14.30-14.60 on stock, orig. 1987 tires, i decided to take the plunge and call Rick Harper http://www.harpersracing.com
Real cool guy - and knows his stuff.
I ended up ordering 009 injectors, Red's 93 chip, Terry Houston downpipe, Walbro 340 w/hotwire, Nitto 275/50/15's, and my machinist buddy made an adj. fuel pressure regulator and trick adj. wastegate (its not like the diagram on this site..it's much better - no need to unclip the rod).
This weekend we had time to install just the injectors, adj. regulator, adj. wastegate and chip.
WOW! This thing acts like a completely new car! Idle is smooth as silk, ALL my idle, hesitation, popping, stumbling problems have vanished, and WOOHOO! This sucker HAULS! I cant believe the difference just those few mods made..id say i have EASILY knocked a FULL second off my 1/4 mile time with just a Red 93, 43# 009's, adj. regulator, and adj wastegate. The T.H. downpipe and 3" CAT comes in next week, and i will install the fuel pump then as well. Tuesday is test n Tune at the track, so i'll know what i run then.
..just wanted to re-post for anyone who was interested..the 43" 009 injectors fixed all my problems, and with Red's 93 chip - the car runs 100% perfect. I have it set for 20lbs of boost right now on 93 octane, and it gets 5-8 spark knock counts over a "simulated" 1/4 mile at WOT for about 15 sec. I can hear it when it reaches full boost (18-20lbs).
Is that safe still? I know i will need higher octane to run that much boost, but what is the best way to get rid of it besides that? I have R43TS plugs gapped at .035...would 42's get rid of it too? I hate to kick down to 17lbs boost when i can run 20 with a few spark knocks over the course of a 1/4 mile. :P It's like giving away a child..it kills me to turn DOWN boost 3lbs!!!
Input anyone? BTW - get the 009's with Red's 93!! You wont believe the difference it makes on a stock GN!
Jay, turn down the boost unless you want to start rebuilding the motor. When you tune the car, you want to see ZERO knock, maybe a degree or two at the very top end of the track or when it shifts, but that's about it. When you get the DP and cat you'll REALLY notice a difference. With decent traction you should be in the 12s with that combo. Now every car is different so I can't guarantee anything but you should be able to hit the 12s without running that much boost. But again, all cars are different but you will be in the low 13s. You want to run as much boost as you can without the knock, if you can hear it then it's WAY too much. Only ways to reduce the knock is reduce the boost, run alky injection or higher octane gas either race or home brewed, ie acetone OR the way I'm gonna go when I can, buy a RJC Power Plate, from what I've heard it's a GREAT investment...just be sure to buy it from Jason, not Ebay. I'm glad you got it worked out, but it was probably the stock injectors were just clogged and not spraying like they used to, generally changing the parts you changed can help clear up problems and make the car run better, ie better idle, better throttle response, but they don't necessarily make you faster. They can get a badly running car running the times it should be. The adj wastegate can make you faster due to more boost, but again, you go too high and BOOM...You've killed it because you thought it would kill you to turn it down. So which is more important, killing you to turn it down three psi (or more) or killing your motor via blown headgaskets? Don't get me wrong, I'm really happy for you, I remember when I changed the inj, chip, turbo and dp on my car...it was AWESOME, I'm just trying to push home the message about too much boost. I'd hate to see you back on here asking where's a good place to go for motor work. I'm sure others will chime in and add their thoughts and if I've said anything wrong I'm sure they'll correct me. Good luck getting to the 12.50s...shouldn't be hard (but it's taken me what seems like forever to get there )
Scott
87 GN
shoot - i knew i was gonna hear that from a pro ;)
Hey - i appreaciate the advice actually. It's a 12K mile beauty, and she's very healthy now - but that doesn't mean i want to replace the motor yet!
I will heed your advice and turn down the boost till spark knock is less.
Man - it REALLY pulls hard at 20 compared to 17 like Red's 93 chip says. But at the track i always run 116 octane so maybe i can get away with it? Would i have to get a full 108 race chip for that to take advantage of it, or will the 93 "learn" whats going on with 116? Im stll stuffy on the whole "chip" topic..i dont fully understand whats changed when i order a new chip. But - im sure the answers are here on the forums Thanks for the advice - i just have this sh*t-eatin grin on my face after all the hours of work finally paying off. I want POWER! :P Im glad to hear you think the Terry Houston DP and CAT will make a huge difference - i hope so for what they cost! One thing about these V6's (and im a big-block V8 guy)..they sure dont "feel" as powerful as an 8cyl. I cant imagine my combo running 12's..it just doesnt seem that fast - but i sure hope it is. The last car i went 12.74 in was a 69 BB Nova, and that thing PINNED me to the seat. It's a different world with turbos it seems. 20lbs vs. 17lbs FEELS like a big difference, but if i can still run that 12.50 at safer boost levels - thats fine with me
Im just trying to prep my car for the TA-49..and with that im supposed to be able to run 20+ with pump gas. How can that be if im knocking at 20 with my stock turbo? Will the DP and free-flow CAT help that? (my current stock CAT is way clogged..it REEKS like rotten eggs immediately after starting). I will find out on tuesday though. Thanks again for the insight - i will soak it in, and turn down my boost for fear of killing my pride & joy. But i'd like to know:
1) Do i REALLY need the Walbro if my stock fuel pump tests & holds a steady 70PSI fuel pressure?
2) If i get the TA-49 with my combo - what boost should i be running on 93 octane, and would a TA-49 even be worh the purchase price/ET gain on 93 octane, or is it only gonna help if i use race gas? Im not talkin about a tenth or two..if i spend $700 on a TA-49..i'd expect 3-4 tenths on that same 93 octane, and maybe .5 more on 116. Is that a realistic goal for a TA49 with my turbo? I'd like to have the reserve power to run 12's with A/C full blast as well - it's not always 40 degrees and dry when a Z06 or Viper GTS pulls up ;)
I really want this completely streetable. If i cant run 12's with this combo on 93 octane all day long - im gonna need help to figure out exactly how i can obtain my goal as cheaply, and reliably as possible using what i currently have. I want to smoke 99.9% of all production cars out of the factory with this baby - ya'll know what i got...what do i need to actually do it?
Thanks again all!
SIMULATED 1/4 MILE. Ill be looking for those tire tracks on some back street. HEHEHEHE
Way to go, Jay. I got the 009's and 93 chip from Rick also. When I did, it was a new car. I thought the car ran good before, boy was I wrong. New 009's and the 93 chip was the best mod I made!!!
I will be watching this thread. I have all the good mods and I am still getting knock also. BTW, I would definately get an upgraded fuel pump and make sure that you hot wire it...
Jay, the best advice I can give you right now, if you're not already on the GNTType mailing list...GET ON IT!!!!!!!!!!! Best thing I ever did and if I would have sooner it would have saved me ALOT of time and money (right Dwight?) There were MANY responses to your post on there. First off....I'm NO pro, but thanks for thinking it. ;)As most of them said, you can leave it at 20psi as long as your right foot is connected to your brain (I love that one!) In other words, you get knock, take your foot OFF! Of course the car pulls harder the more boost it gets, that's just how they work, pretty cool huh?
Are you mixing the 116 with the pump gas in the tank? That tends to really lower your octane. I run straight 116, just to help give me a "fudge" factor. In all honesty about the 93 vs 108 chip, I'm not sure about the performance gain. Before somebody bites my head off, what I mean is I've run my car on 93 octane with a 93 octane chip and ran 12.50s, with 116 and a race 108 chip, I've run a 12.48. It's probably just me and the car....(right Dwight?) The biggest thing to remember here is every car is different. You can have two cars that are identical with their parts but both need their own setup(tune) to run right, can't just set them both the same. The "race" chips, from my understanding, give you more timing which can give you more power, the key is tuning it, getting the power to the ground, and tuning it. Did I mention tune it?? You need something to tune with, I prefer TurboLink, it's simple and cheap. The chips don't learn anything, they just tell the car/motor what to do based upon certain info it gets from the sensors. Be awesome if you only needed one chip and it learned everything.
If you think that grin won't come off now, wait until the dp and cat. People have varying opinions on the cat, I have a 3 inch Random Technologies Cat, it works great even though I accidentally damaged it and had to remove the internals (whole other story.) I was a small-block guy, so I know what you mean. I'll tell you a small part of "My Story." Before I upgraded my car, I could take off from a dead stop, with the pedal on the floor and the tires would start to break loose around 7psi and spin until I hit about 30mph, but only with me in the car, anyone else and it just went, no spinning of the tires. We put on a 3inch downpipe and cat (maybe put a TA49 on at the same time, but don't think so.) Then I took it out with one of my 200lb friends in the passenger seat. At 5psi the tires started to spin a little, sounded like they were loosing a traction battle, but by 7 psi they lost hard! The tires would spin and whereas before the speedo would wave between 25 and 50mph, now it shot from 25 to 75 mph. It would stop spinning after it shifted into second, about 30 mph. My friend just about peed his pants. Of course I had to take the OTHER friend for a ride after he heard the first one's story.
As far as the TA49, it's just a more efficient turbo than the stock one. So at a given boost level, it builds less heat than the stocker. Essentially then you can run higher boost with less knock because the intake charge isn't as hot as it would be with a stocker. I'm sure if I screwed that up, someone who really is a Pro will comment. I'm not sure who told you that you can run 20+psi with pump gas. For some reason I can run or have run 20psi with no knock but I've been told I'm lucky, really lucky. No two cars are the same but I'd say that you shouldn't be able to run 20psi on pump gas, not without alky or maybe one of Jason's Power Plates.(If I could get a nickel for everytime I mention that thing.. I'd have one...they're cheap $59 last I checked.) I normally had my car set to about 17psi, but I've been told that THAT is even a little lucky, most run around 14psi, just to be safe. One tank of bad gas and BOOM! The TA49 will make your intake charge temp go down, so for instance, if you could run 17psi and get 1 degree of knock, and your intake temp was (complete guess and only an easy number for comparison sake) 200 degrees with the stock turbo, then the 49 at 17 psi could (maybe) get you 0 knock because the intake temp was only 175. Again, those numbers are probably way off, just to show you how I think it works, I'm sure someone will run in and smack me if I'm wrong, then explain to you the real way.
With the BB Nova, you probably just hit the gas and went right? Well with the GN, you have to build boost at the line, start with around 7psi and see what happens. Everybody does things a little different, you just need to find out what your car likes. But make sure you try to build boost, then the car if it hooks, will pin you to the seat and keep you there until you let off. Man I miss my car.
I've lied enough for tonight, I'm sure others will pop in and cover things I may have screwed up or didn't cover at all. Good luck. hehe if I keep this up somebodies gonna tell me to shut up. I've started typing and I can't stop.lol
Red makes a 100 street/strip chip which will allow
you to run 19+ on the combo of pump/race gas. Normally i mix 2gal 93 and 5gl 112. For all out
racing the Reds 108 chip is great but you need at least the 108 mix. In either case find yourself
a back road to learn the right boost/knock combo
and remember adjustments. If not when you get to the track your'e wasting time testing and tuning.
Another item you might want to look into is Eastern Perf manual boost controller. To some extent you can adjust your boost from inside the
car.
Thanks frank - ive been trying to perfect the launch now with the nitto's, but i cant tell whats making me faster in the 60-foot aspect
It "feels" strong launching at about 6lbs of boost, and anything over 8 spins the drag radials..hehehe. I was looking into the Boost Commander from ramchargers..is that the same thing? I looked at the description, but couldn't figure out exactly what that thing does, but i was going to get it.
Does anyone know what this thing does exactly, and if it's worth $130? The description for it on ramchargers' site doesn't tell me anything really.
thanks for the input fellas..i'll see if Red can get me a 100 chip in time for next week
The Ramcharger unit is electronic while the ESP is vacuum. I decided years ago the less elect gadgets the better when the car has problems.
As for the launch i hope your'e using the airbag.
Jay I hate to tell you, but even with a TA-49 there is now way you'll be running 20 lbs. of boost and not have an engine that pings at WOT. 17-18 lbs. seems to be the most that I've seen off of pump gas, between my dads GN and my T-Type. I don't see 20 + lbs. of boost as a reasonable goal on pump gas unless you spray alcohol and that's a pain in the ass to tune with as my dad is finding out. When you put on the TH Downpipe make sure you turn the boost down some otherwise your first time out with it on you'll blow your engine, the boost level will go up.
shoot no 20lbs boost for me then
well..thanks for the inside info on that TH downpipe - it's duly noted. I appreciate the assistance fellas.
>
Huh???????? I haven't seen him ask for help. No black magic getting an alky set up to perform. Tuning is tuning.
Hank
to xxninja and the others with the same problem -- so do I and I've had it on scan tools , scopes etc - -and they couldn't find a thing . Lost its top end and surges at steady throttle at any speed yet pulls good from say 20 mph to 60 mph .Did you guys figure out what it was Tks