New owner questions

[turbowannabe]

Hey guys,

Well I just bought a 1987 GN hardtop that now has 93,000 miles on it after the drive home from florida. The car is in pretty good condition, with the only major imperfections on the drivers side. But I'm not really worried about the exterior, it looks fine for what it is now. The car runs top notch when it's up and running, but kind of stumbles at idle and a little when I just press the pedal lightly to get the car going. After I get up the rpms a little bit or the car gets up to higher temp everything is fine. When I bought the car the check engine light came on and the guy showed me the code 44 that the scanmaster was picking up. He told me it was a rich code caused by the 50lb injectors, and if you let the car sit at idle too long it would set the engine light but would turn off after you got driving. He took us on a ride and sure enough the check engine light went out, but still showed code 44 up till yesterday when I reset the computer. Now it hasn't come back.

The car has been running really cold( runs in the 130's and 140's unless I let it sit and warm up someplace, but stays cool when on open road), probably due to the obvious temperature difference between florida which was 86 when we left and it is now in the 30's here. My target temp area would be around high 160's low 170's. I'm thinking it's the 02 sensor, since it will go to all zeros if i'm driving and let off the gas, and when accelerating it goes between .020 and.090. I still don't know exactly how to read it but i've been learning, shouldn't it bounce from really low to really high to show a rich to lean condition idicating an properly operating 02 sensor? Plus the blm is pegged at 150 most of the time. Here's what my scanmaster has been showing at idle

02 volts- has been really wierd, kind of explained it above
tps- 42 just about perfect
Maf- 4
int- 149
blm- pegged at 150 most of the time
lv8-30-36
Iac- 9-11

I forgot to mention I also have underdrive pulleys and a Joe Lubrant chip

I'm going to go buy a new oxygen sensor and IAC tomorrow, am probably going to buy a 180 thermostat to get things back up to temp, and I already bought some replacement vacuum hose ends today, and am planning on doing a full spring cleaning this weekend. Does anyone recommend using engine flush?

What are all the functions of the scanmaster and how to I read it. I'm learning a little but I'd like to know as much as possible. I read that the numbers the scanmaster reads are different between whatever chip your running, is that true? There's a few more readouts than the ones i listed, besides the obvious ones like mph and rpm and temp, i think one is intake air temp What should I keep knock below? Does any of this look abnormal to you? Let me know what you think

thanks
Dan

 

[turbo nasty]

congrats on your GN!!!!!

First thing is do you HOMEWORK....i.e. go through gnttype.org, this site and ****************, read...read...read..read

First thing when I see a code 44 is the 02 sensor. I have used the bosch sensors from the popular parts store and, yeah they work... but not as consistant as the AC Delco AFS-22 (o2 for the GNX).

The hesitation that you spoke of when you initially push the pedal...commomnly called "tip in stumble". This is common with these cars due to the IAC tps not adjusted correctly. Your IAC counts are low should be between 15- 50 and higher count in gear than at idle.And your TPS is a little low for my book.Heres a procedure to adjust.

Car at full operating temp turn off engine and put a jumper on the upper row right 2 term on the adl port(under radio poddri side) now with the jumper in place. turn key on NO Start and leave it there. Now go and disconnect the IAC elec connector from the IAC. Leave it off, You may have to take off the hard pipe/duct to get to it.
Remove the little cover over the min air blade setting screw if your car still has it on.
Now go back and turn key OFF and REMOVE jumper.
(For this next step I recommend someone to help you) Now start the car, if it will not stay running try turning the screw in a little at a time until you get it to stay alive. Now adjust the RPM to around 650 rpm in GEAR.
Turn OFF ignition, plug IAC conn back in.
Key on NO start and adjust your tps volts to .45 -.47 @ idle and 4.6 -4.7 WOT.
Now reset the computer (remove power for a few moments).

Coolant temps are to low, bet the chip is burnt fo a 160 t stat not a 180. But say the car has a 160 tstat in there and a super super efficient radiator the temps should try to stay around 160 the tstat may not be closing all the way. Get some GM top engine cleaner(liquid) and decarbonize the engine.
Good Luck

 

[ES1]

BLM @ 150 is a rich condition which is why the code 44
Vaccum leak?
02 volts will be all over the place
On SM do the cc count recycle slow or fast?
Slow - bad 02

 

[TurboDave]

Originally posted by ES1
BLM @ 150 is a rich condition which is why the code 44
Vaccum leak?
02 volts will be all over the place
On SM do the cc count recycle slow or fast?
Slow - bad 02

Just as a clerification, BLM @ 150 is NOT a rich condition. What the 150 tells us is that the ECM is adding a LOT of fuel to compensate for an overly lean condition (which of course could cause an overly rich condition).
Usually caused by a vacuum leak or pre turbo exhaust leak.

 

[MistaScott]

BLM @ 150 is actually a lean condition caused by unmetered air entering the system. The ECM has to dump fuel to get the mixture back up to par. Usually it is a vacuum leak but it can also be a bad MAF, exhaust leak, etc.

You shouldn't need a new IAC sensor -- work with the one you have and make sure it is adjusted to spec. Also, the o2 isn't necessarily bad. You should test the stuff before you go throwing $$ into it. Also, a 180 degree stat isn't going to make your temp rise necessarily. Usually it's the chip.

Get associated with the search function on this website and closely peruse www.gnttype.org.

You should have no knock at stock boost levels. AT is mass air temp which is used to a small degree by the ECM for the air/fuel calculation.

http://www.ramchargers.com/RamNews/Translator/scan2_manual.htm

That may help you learn scanmaster.

 

[ES1]

150 rich???
No more posting for me before coffee

 

[turbowannabe]

Well I just got back from town, I bought a new IAC and GM top engine cleaner and ordered a GNX 02 sensor. I'm pretty confident that both are bad. The car died at idle this morning after I started it up and walked away, I'm getting different IAC readings a lot. It's surging also. I said before that it was at 9-11 but this afternoon i saw in the 20's and it idled alright. If I'm cruising down the road and I let out on the throttle it gives me all zero's, it shouldn't do that should it? And also when I give slight acceleration pedal it gives me really low numbers under 100 and it pretty much stays like that. BLM stays pegged that's another reason I think sensor after lean code 44. Thing is after I reset the computer the other day the code has not come back.

I'm just going to change out the sensors so I know where I'm at with the car. The tps numbers while running at idle in park is actually 44, 42 with the key in the run position. I got 4.73 with key in on position and pedal to the floor. Was that the directions for setting tps or iac? Now that I think about it I guess I could see if I could just adjust the IAC and save myself the $60 i just paid, I just didn't want to be working on it tomorrow and find out I do need a new IAC and be out of luck. I work for a technician so I'll have him help me get that all tuned up tomorrow. The gnx 02 sensor is going in though. I bought some vacuum hose connectors at advanced auto, but i'm not sure they are the correct ones, where's the best place to get them? Also what's the best way to find vac leaks? Leaky exhaust would be pretty noticable wouldn't it? I'm pulling 18 lbs of boost, and I saw it spike to above 20 when the guy took us on a ride in it. I'm purchasing a boost controller with duel solenoid setup on it to prevent that spiking.

What should I do about the temp? I'm pretty sure the fan doesn't even come on till 167 degrees, so i'm thinking it needs a new thermostat. Has anyone heard of any problems with the joe lubrant chips? All i have heard is that he's kind of conservative. There's a guy running an 11 second GN that lives about 10 minutes away from me that I have talked to and will help me out, but I don't want to be a pest and bother him all the time. I would like to do as much as possible by myself, we all know it makes you feel better when you do something yourself.

Let me know what you think

thanks
Dan

 

[MistaScott]

1) IACs should be about $33 Try www.gmpartsdirect.com in the future. The numbers sound funky, they should go up as you give it throttle so you may be right about the sensor.

2) The best BLM procedure is as follows:
Get a piece of gasket material and place it under the vacuum block on the top of the throttle body. Use some gasket dealer and screw it down. Reset the ECM (unplug power wire). Fire up the engine and observe BLMs. If they go down, you have a vac leak.

If vac leak, get a MityVac at Autozone and test the vac lines individually. Most common causes are bad check valves, EGR and canister solenoids, incorrect PCV valve (so check to make sure you have an AC Delco PCV, should say #893 on it).

If the vac test doesn't lower BLMs it is either exhaust, injectors, MAF, or pre-throttle body air leak (intercooler, piping, etc.).

Exhaust is not always noticeable, especially a cracked header. Test exhaust with some GM top engine cleaner sprayed into the throttle body at idle. You will see smoke at any exhaust leak.

To rule out a pre-throttle body leak, attach MAF directly to the throttle body and see if that corrects BLM. Reset ECM after every change you make.

Test fuel pressure. If low, you have a pump or rail problem.

Test injectors and MAF -- more complicated, they would be my last test.

 

[turbowannabe]

I have more problems since I last posted. I drove the car a couple miles away to my buddies house and go to leave no more than two hours later and it's shuddering under acceleration. It kind of sounds like I can here an exhaust leak somewhere around the turbo area. I'm thinking either exhaust leak or vac leak. I did notice some oily substance on the rear of the billet vacuum block on top of the plenum.

I noticed a couple of electrical fittings under the hood that were not connected. Two didn't seem to have anything that they would plug into which were on the driver side; the other one was on the driver side and when i plugged it sounded like a fan was constantly running under the dash or something. I will take digital photos of them. I'm going outside to work on it right after I get done here.

It has a fuel pressure gauge under the hood connected to fuel rail, with the vacuum fitting on it it is reading around 42 lbs. When I rev the engine the pressure goes up. I'm going to pull the computer out and check out the chip. The wierd thing is that it's gettin worse. I don't see how it could start doing this so quickly, but that's what half the fun is... fixing it.

thanks
Dan

 

[MistaScott]

Best advice I can give: turn the machine off, go inside, spend about 3 hours reading and searching this website and the others (t b s.com, t6p.com, gnttype.org especially). Learn the engine diagram, where everything is, the vac system, wastegate hoses etc. Then go over everything carefully on the car (spring cleaning on gnttype.org if you haven't done it). Don't want to see you blow headgaskets to start your TR career.

 

[turbowannabe]

that's what i'm doing right now, searching over other people's posts. Well actually I already started my TR career in Aug 2002 with a 2 piece crank, i'm part of the DOTCC is it? What does that mean again, I don't remember for sure. So I'm not looking for anything like that to happen again. I'm not going to drive it untill I know it's fixed. Good thing I've got a top and bottom snap-on box full of tools in the barn. Which way do I turn the wastegate to lower boost, i might as well lower it as much as I can untill I know exactly what I'm doing.

I forgot to mention, that earlier before the car was running bad all of the time I tried to just calmly powerbrake it to see if the engine would sputter or anything and it was surging like it is now. I read that my fuel pressure should be at 42 with line off with my injectors, is that correct? The things gotta be getting flooded with fuel with my blm at 150 and those 50lb injectors on there. I'll pull the plugs and see. Where have you found the best place to get vacuum hose and hose ends? I might as well redo all of my vac lines while I'm at it.

Let me know
Dan

 

[MistaScott]

Where have you found the best place to get vacuum hose and hose ends? I might as well redo all of my vac lines while I'm at it.

Let me know
Dan

Pegged at 150 means that despite the ECMs best effort, it is still lean. So no the 50#ers aren't gonna flood it. What are your BLMs in drive? If they go down then likely it is vacuum.

Vac hose -- Advance Auto. Most of it is 9/32 or 7/32 or 5/32. Just match it up with the old. You may also need new check valves (the circular things in the vac line prior to the EGR and the canister).

Yeah redo the vac lines, I blew my headgasket cause I didn't. Good luck.

 

[turbowannabe]

i just got a whole bunch of vac hose from my boss, i'm going to replace as much as i can right now. He also gave me a box full of vac t's, but I don't have check valves. The blm's do get better once I get driving. It has a pre-turbo exhaust leak, but I can't tell exactly where it's comming from. I'll be spending the good part of today working on it. If the headers are leaking then I'm just going to buy some ceramic coated stainless steel ones so I won't ever have to worry about it again. I just can't believe how much worse it got over the course of a couple days, it was just stumbling a little off bottom end. I believe my symptoms are a combination of exhaust leak and vac leak(lucky me, but i'm sure I'm not the first or last to have this happen). I don't think the car is actually running lean, the leaks are just making the computer think that and it's richening it up, because I can smell gas really bad. My gas mileage went to crap. Under 200 miles and used over 3/4 tank of gas. Hopefully I'll get everything straightened out today, but I'm not counting on it. I'll let you know how it turns out


thanks
Dan

 

[DCVING 6]

Dan,
first off, congrads on the new car.

Try getting a hold of "razor" on this borad... the guy that does the alky control kits. If I remember correctly, he had two customers with BLM problems, the common link with the cars was the Jay Jackson throttle bodies. Maybe he can help you out a bit.

 

[Pronto]

After reading your sig, I see that your car is modified so a few of those mods could be faulty. I would first go though all the vacuum lines. Bet more than one is porous. Several things have to be confirmed but will need to be looked at before just replacing. What chip and specs are in there, what thermostat is in there, do you really have 50 lb injectors, is the alchy injection working correctly, what spark plugs in there. With so much going on it may be worth your while to find some local TB guys to talk to. Take your time with this. Once you straighten out some stuff you'll be OK. Then the fun begins!

 

[turbowannabe]

Thanks for the input guys, I really appreciate it. I just got back inside from 6 hours of working on my car, I was taking my time. Replaced quite a few vac hoses, some of them looked really bad. I got most all of them, and I will replace the rest of them and the check valves once I go to the store tomorrow. there's a few lines that arent' connected to anything, I will take pictures of them tomorrow to see if they are anything important; I'm thinking one or two are for the cruise control that was taken out. I forgot to check the blm between changing the hoses and taking the up pipe off. But with the up pipe and ma off it was around high 120's low 130's. I found my exhaust leak, It's at the turbo exhaust entrance. Poored some top engine cleaner in and the smoke led me to the leak. I'll make sure tomorrow that there aren't any more leaks. I pulled the drivers side plugs and they all looked fine, really tan, they were NGK's but I've already got AC Cr43ts's to go in after i finish up the top engine clean. Still need to get a pcv, the correct one is in there I carb cleaned it for the time being.

I almost thought when I first changed the oil, before I did anything else, that I blew a headgasket to boot. The oil looked somewhat chocolate milk like and when I looked at it in the drain pan I thought it looked like oil and coolant seperating in it. But I think it was just the extra fuel mixed in with the oil. I noticed the injectors had 44.7 and the date engraved on them, looks as if someone flow tested them. I know 50lb injectors means at 100% duty cycle, so that could still be a 50lb injector? I need to check the chip out, haven't done that yet. All I know is that it has a Joe Lubrant street chip in it.

I'm pretty sure the alky system is working fine. It was a home made deal, but is still pretty nice. Has one of those mist nozzles like at amusement parks in there I guess, with stock fuel pump in the tank as alky pump and a hobbs switch under the hood connected to the same line the boost guage is connected too, starts spraying and turns on the power injection light in the dash once I hit around 13 lbs. Has a switch in the dash to turn it on and off. I think it's a pretty decent setup. I should get a fuel pressure guage for it. The tank has lost alky between when he took us on rides and me owning it now, I haven't used it but the 3 times i've full throttled it. Would the alcohol that modifieds run be fine to run in it, I don't want to go to the paint store to pay $5 a gallon for denatured alchohol. I'm going to mix klotz fuel lubricant to it also, as instructed by Tom Wilson who is the guy running the 11 second GN and lives near me.

Where should I get the gasket at? I need to also replace the vacuum block gasket. At first I was kinda upset that I had to do so much work to my car so soon, but really now I'm glad. This just makes sure I'll do all the good stuff like the full spring cleaning and all that to make sure everything is exactly where it needs to be. Also, I enjoy working on the car, it makes me have a greater respect for it. Anyways, thanks for all of your help I'll fill you in on tomorrows events.

thanks a lot
Dan

 

[turbowannabe]

Well, I just ordered a composite header to turbo gasket, new 160 degree thermostat, and a pcv check valve from ramchargers today; and like I mentioned before I'm purchasing a brand new BSTC, y connector and extra solenoid from a tb.com member. Did I waiste my money on the check valve, I did a search and a few people suggested it to reduce oil leaks which I have a few. Should I just resell the BSTC once I get it and spend my money elsewhere? The boost will spike up into the 20's at first and level off at about 18, I figured the extra solenoid would help having quicker reactions to bypassing exhaust and I could keep my boost way low for more economic driving. What else should I look for to replace? Let me know what you think


thanks
Dan

 

[INEEDAGN]

Well I am also really new to this but i'm pretty sure the o2's going to zero while letting off is normal. It's called DFCO Deceleration Fuel Cut Off and it's an emissions thing mainly. Hopefully someone who knows can either back me up or correct me if i'm wrong. Anyone????

hope this helped

bob

 

[MistaScott]

Don't go buy headers, get your stock ones welded if there's a leak. Headers on these cars are fine. Save your money.

PCV check valve isn't really necessary IMO. Don't buy the one that replaces the PCV valve, I have heard bad things about them. Regardless, they do not reduce oil leaks. They prevent boost pressure from getting into the crankcase which is something the PCV valve should be doing anyway.

Exhaust leak can explain a 150 BLM so you may have found your entire problem.

 

[stealth908]

hey man. i've enjoyed reading this post. there's been alot of good info in here.

what's new with the car?

i grew up in illinois, and all of my family still lives there. what's happening out there?

travis