thunder69n

I have an 87 pontiac firebird Automatic v6 2.8 When you start her up and she hasn't been running, It turns over and the rpms jump up and down while it chugs, usually let it sit a minute or give some gas to keep from stalling out, then it will settle down and seem fine. When driving the check engine light will turn on and the rpms will drop and the car will die, ( but usually no warning) Car will die randomly while driving. Sometimes can see the car will stutter while driving.

http://www.youtube.com/watch?v=J05oriOdv9A video of rpm jumping on startup.

I ended up geting a code 34 from the cars computer wich book says Mass airflow sensor.

I replaced the mass airflow sensor

Replaced, Oxygen sensor

Replaced spark plugs ( did not replaced distributor/ plug wires yet. But they appear uncracked)
update: Replaced plugs, wires, dizzy cap and rotor.

Replaced PCV valve

Had alternator/battery/starter tested ok


Previously did oil/ filter change.
Fuel Filter change
Air filter.


Looks like a hole on bottom of transmission or the bell housing maybe that transmission slides into , but she shifts just fine.

Still starts like ****.
Any ideas apreciated.

thunder69n

Went to Autozone equivalent store to return o2 sensor socket I rented. and but more parts, well the clerk was having a bad day and didnt sell me any of the parts I wanted to pay for. But asked if Ive changed the coolent, and I hadn't yet and noticed some hoses may be gettign older. Then I rememberd seeing a hole under the car when i was doing the O2 sensor
Seen antifreeze along the metal near the hole.

Clerk asked if water was coming out of it, and that it is a drain hole and likly my water pump seal is leaking.
Does this sound at all correct. I know I am gonna have a hell of a time replacing it, so looking for anything to go on with that before I change it.

thunder69n

took out IAC, was some carbon built upon it, tryd cleaning it and were it fits into throttle body with just paper towel for now, off in search of carb cleaner, when I put back on got me stalling a few times in a 5 min drive.

thunder69n

took throttle body off and cleand that. No such luck.
Friend suggested fuel pump. Would like to be sure of that, but going to go through tomorrow what I imagine will not be fun of dropping my tank and replacing another expensive part. Does Fuel pump sound at all like it could cause this issue. and going to figure out how to get to fuel injectors to clean them.

thunder69n

So started getting at removing the Fuel tank. Very disapointing. But We got the main heatsheild off from under tank.
Did I mention all this is new to me? guess we gotta learn some how

Book says to remove fuel tank, to remove rear axle...

In another thread someone said that all that hols the rear end is a suspension bar and somthing else wich I veleive top be the brace that is in the way of my fuel tank that has 3 bolts 5/8 on the drivers side, and the on passenger side 18mm was it going through a bushing, theres a nut on one end of the bolt and a big bushing in between that my stabalizer i belive also attaches and i need to unbolt form there as well, got nut of one side of the bushing so far but not the bolt. and other one broke my ratchet, have breaker bar but the bolt is turning and need to go buy a 18mm wrench to hold it and maybe uncrew it after.
one the hangers for my exhaughst was welded on. I chizeld it off on passenger side. Exhaughst wont come out though it can't get over the rear axle

thunder69n

So I finanlly got the fuel pump replaced and everything back together when I learn how to change the brakes. after the shoes and springs all in place, the drums dont fit over the pads ?? so i try to pump the brakes not sure how you make them squish together anymore then they are. theres the adjuster at bottom one is out a little oneis all the way in , no difference. My lines leaking . had rear end held with a jack that failed, looks like more learning more time without a car and more money on new tools / parts.

thunder69n

after plugging in fuel lines at tank wrong and killing the charcoal in my charcaol canister and a week or so of hell changing a fuel pump that wasn't bad.
I come back to leak under the car it is oil that is leaking, and its when the car is turned on that it leaks.

looks like oil end up coming out a drain whole on bottom of transmission, what do you think is leaking up in there, under hood don't see any leaks without taking engine apart to get under there.

http://www.youtube.com/watch?v=PNH7uJ-C9YQ is were I see oil dripping to ground when car is on

thunder69n

Changed o ring on distributor even tho o ring looks brand new. Dizzy on other hand looks like poop http://www.youtube.com/watch?v=lgo8-pipUyY

TwinTurboROC

that piece with the hole, (torque converter cover) can be removed to ckeck the rear main engine seal to see if its leaking. its 4 10mm screw. its normally plastic on v8's. to fix that seal you have to seperate the engine and trany, lotsa work, if u can deal with the leak leave it be unless its leaking terribly

TwinTurboROC

from what you've said so far, sounds like maybe a bad module in the distributor, have you checked your plugs to see what color they are.. if there covered in black soot, ignition/dist problem, or maybe a fragged ecm. keep us posted

thunder69n

Wow hey thanks TwinTurbo. the module in the distributor is it the peice on top, with the coil, under the rotor?

Replaced plugs, wires, dizzy cap and rotor. Preivious plugs were coated with rust

Here is a video of my distributor, new one going in tonight. http://www.youtube.com/watch?v=BSLFx--EGvA


And heres a vid of the usual starting RPM issue. http://www.youtube.com/watch?v=J05oriOdv9A

A look under my oil cap at the add a quart mark http://www.youtube.com/watch?v=qe6jMPXFh30.

Thanks for your time

92FBirdVert

iTrader: (1)

could be the IAC valve or the egr.

thunder69n

by egr, is that a part in the emmisions? that works with the charcoal canister? Is it the solenoid? or is it somthing else?

NINÅ

thunder69n

New dizzy/ with module/ pickup coil installed. and yeah no difference, last bolt being pain on the torque converter cover so Ill be tugging on it again when get outa work tommorow.

TwinTurboROC

hey dude stop putting new parts in the car, youll waste alot of money like that. ive seen that problem before, with the check engine light flashing (orange light flashing in youtube vid) and idling like that but my brain aint working right now. do you access to a spare ecm? just to swap it in, cuz i thinks yours might be boned. also check the pcm grounds etc, its harness to make sure its not loose.

just a side note, check your battery ground and pos, check the chassis ground and block ground.

thunder69n

Found were my EGR valve is, grr looks liek has a solenoid to, so if I go through my route of replacing stuff thats gone way out of my budget, guess i'd be replacing those two things. http://www.youtube.com/watch?v=pGyw06Vpivk

Yeah kinda feel like im f'ing myself on this one, bought it for more then ever payed for a third gen, specially for being auto and no t's. it seemd pretty mint except for the rust. nah don't have access to spare ecm. but ill look at what I can with it.

TwinTurboROC

why are you replacing so many parts?

thunder69n

becouse I need to be able to drive to work

New ecm and egr valve orderd. Have new IAC in hand, incase cleaning the old didn't work

Whats the difference between if ecm is operating in closed or open loop?

92FBirdVert

iTrader: (1)

the egr is part of emmissions

TwinTurboROC

im doubtful the egr is causing this, from what i saw looks like the pcm may be jumping modes upon startup, aka limp to open/closed, basic explination open loop = maf/map ecm fuel mode, closed = o2 sensor fuel mode, theres more to it than that, but too much to detail explain,

do one more test, unplug the coolant temp sensor, and start the car to see if it acts different, this WILL set a code and engine light.you can clear it after the test by by reconnecting the coolant temp harness then disconnecting the neg batt for 1 min.

thunder69n

is the coolent temperature sensor same as thermostat? looks like its somthing different. Where might I find her?

thinking its the one with the smaller nut with black and yellow wire on connector. The bigger should should be a fuel injectors.

http://www.youtube.com/watch?v=h0ProZP13Sk coolant sensor?

thunder69n

still ruff start idle, when unplugged coolent sensor

new egr valve

new solenoid to my charcoal canister.

thunder69n

The rpm on start seemd fixed with new solenoid to me charcoal canister. On startup the new solenoid is not engaged, and the rpm is fine, when car heats up or vapor forms enough pressure? solenoid opens up and car starts surging rpms.
With car still on and constently surging, if I unplug both hoses from vapor canister solenoid the car idles ok.
Solenoid seemd to get really hot.

Heres what my leak I need to fix looks like atm http://www.youtube.com/watch?v=ulNWW4e5B1w
Blah guys at part store say garbage motor couse of blown head gasket. They figure this becouse of the anti-freeze She sounds so good right now

Chevy86 IROC-Z

iTrader: (17)

Thats leak is coming out of the flywheel/torque converter shield. Either your rear main seal is going bad, or the front pump seal is going back. To find out which is leaking, get a white paper towel and rubb off the oil. If its reddish, then it tranny fluid. If its black or honey colored, then its oil. Usually your can tell just by the smell. Either way. If you decide to fix the leak, you will have to drop the tranny to gain access to either seals.

Chevy86 IROC-Z

iTrader: (17)

I just looked at your video. Im about 99% positive that its your rear main seal that is going bad. I know that it cant be the front pump on the tranny because that seal is in between the torque converter and the tranny. the leak is obviously between the flexplate and the rear of the engine. Now that I think of it, go under the hood and reach with your hand and feel the back of the intake manifold. All TPI engines require a large amount of silicone gasket to be applied in the backside area where the intake manifold and the block meet. There is a gap that must be sealed off. Im not to sure but if the rear seal is good, then maby, just maby the silicone has gone bad and oil vapors are exiting that area in such amounts that it is collecting and leaking down the back of the engine. But that is just a step that you may want to test. I still say its the rear main seal though.

thunder69n

Nice Iroc, yeah don't belive any trany fluid coming out. had taken torque convetor cover off and couldn't tell were coming from.
as this last vid and look under torgue convertor cover http://www.youtube.com/watch?v=ulNWW4e5B1w I see few drips of antifreeze and few of oil. Ill see if can check anything out with the manifolds, thanks.

Chevy86 IROC-Z

iTrader: (17)

Thanks for the compliment. Okay. The antifreeze may be a big issue here. Either a freeze plug is going bad, or the head gasket is going bad. BUT, if it is indeed the head gasket going bad, then you should also feel around the head to see if there is oil+anti freeze leaking. If there is oil and anti freeze present around where the heads and block meet, then that would be your problem, a blown head gasket.

TwinTurboROC

so the idling problem is fixed? if so is that due to the solenoid?

thunder69n

Well if my solenoid is hooked up the check engine light comes on when the rpms juimp.
I noticed that I have been gettign the rpm issue still. So as of the moment with the vacuum lines sucking in air that go to the solenoid ( solenoid removed) the car still doing the rpm jumping on start but withought the check engine light at flashing at the same time.
If plug solenoid in and vacuum lines go through there and prolly canister rpms jump with check engine light flashing. The car hasn't died in a few days.
I put screws back in the vacuum lines couse it was raining and got a code for my o2 seonsor at one point while I was driving my brother to work. It may be me, but the exhaust sounds like poop when the vaccumm lines are sucking in air. And sounds great when they are plugged up. Had taken the screws out of the lines originally becouse wasn't sure about having them plugged up with not having a venting gas cap.
I drove home with the vaccum lines plugged up, opend gas cap and no preassure built up at that time.

This O2 sensor code I got is 2nd code ive gotten at all with this car. last time was maf sensor. both have been replaced. will drive little more when I do with the screws in the lines see how it goes, may try replacing the o2 sensor again just in case when car cools down overnight.

TwinTurboROC

you got any vac leaks, you can check by spraying a little carb clean around vac hoses and the intake, small amounts. be carefull of the fumes, keep it away from coil dist plug-wires hot exhaust manifolds, its flamable...jesus eff i cant spell

thunder69n

Changed out couple peices of vacuum hose when found diagrams and got opportunity to take throttle bodg off again, ran fine for couple days as it seems to when I do any work on her and reset the computer, was parked in the sun while I was at work when I got out, turned the engine over and the check light blinking with the rpms going, disconnected the electrical to the vacuum solenoid leaving the lines connected this time driving good for another Couple days