XxXChrisGXxX

iTrader: (1)

2.8L V6

New:
Distrubutor Cap, Rotor, Ignition Module, Ignition Stator, Ignition Coil, Spark Plugs, Spark Plugs Wires, TPS, IAC, CTS, Oil Sending Unit, MAF, Power Brake Booster, Vapor Canister Filter, O2 Sensor, Cat Convt, Complete Head Set, Gaskets Etc, Fuel Filter

Ok now my car has a very rough shakey idle, I've tried to adjust the minumum air several 1,000 times with a failed attempt of not acheiving that smooth idle I've been seeking (my g.f has a perfectly running 87 camaro 2.8L I also tried to count her threads which is about 6 and doing it that way then adjusted TPS .55) ground aldl wait 45 seconds disconnect IAC and EST then remove ground start car, replace ground let it go into close loop adjust idle to 550 in big D (i do this and then the car is still very rough and shakey and seems either low or high, the car has about between 17-22 steady vacuum in hg, and has no codes, going to compression check it tomm, and I was just wondering anybody have any clues? I get terrible MPG, and also I believe my fuel filler neck is leaking can that contribute to this problem? or is it something else? Also the car takes about 10 seconds to start when cold about 24 hours of a sit.

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My opnions on it are either bad compression due to leaky valves/incorrect valve timing, or bad fuel pressure or cold start injector? also could a bad air temp sensor have anything to do with it?

Maverick H1L

iTrader: (8)

What's the fuel injector impedance per bank? Between the first and third terminals on the front injector harness connector (disconnect the rear to avoid ECM damage as well), either way, you should read close to 4 ohms resistance. It sounds like you have a leaky injector or one or 2 with a bad coil inside. CSI should only operate on startup, if it works at all, as it is on the same circuit as the starter solenoid, and is controlled by a temperature switch. If you feel that you must disconnect the CSI tube from the fuel rail, be careful NOT to lose the o-ring inside the fitting. The only way to get a replacement is in a package that costs $10.

However, you are going about setting your idle speed the wrong way. Set your base timing first (10* BTDC, 2nd V notch in the tab, IIRC). DO NOT disconnect the EST to set your idle speed. BTW, idle speed should be 700 RPM, not 550.

Compression check should yield about 160 PSI per cylinder, IIRC, maybe more. The proper valve setting is 1/4 turn on the nut after all play in the pushrod has been removed.

Fuel pressure should be 43 PSI when not running and not lose even 1 PSI of pressure over a period of 20 minutes, and 39 when running if the regulator is working.

BTW, where in CT are you? I know a few guys out there and went to school in East Windsor...

:edit: Also, make sure you have no breaks in any vacuum hoses, between the MAF sensor and the throttle body, that the o-rings on the injectors are sealing, and the elbows for the PCV system on the valve covers are sealing and not loose. Does your engine have that annoying nylon pipe running from the back of the intake to the throttle body? If it does, I can tell you how to replace it with something that works.

XxXChrisGXxX

iTrader: (1)

the idle should be 550 for setting minimum idle speed, not the actual idle of the car, I used TomP's actual GM Service Manual for the 2.8L for setting my minumum idle speed adjustment it also says it in the haynes, and other repair manuals. The base timing is at 10*, the pcv system is leak free, the maf and ALL vacuum lines are all new except for that annoying one you spoke about LOL the one behind the intake, btw gm service manual says to disconnect that 1 wire back left above the A/C crap and the IAC motor after grounding ALDL for 45 seconds to adjust minimum idle, but as for my injectors how do I test them I don't quite understand what you mean..

Btw I'm in Bristol, CT and the only person I know in CT from thirdgen is tpi-hearse lol, but soon to be someone else as I'm thinking about just putting in another 2.8 and use all my new sensors lol.. but would love some help on this peice of junk thats been costing me money when I run it.

Also I have these annoying leaks right where the exhaust donut gasket meets the manifold on both sides, and they are both new exhaust gaskets, new exhaust manifold studs and nuts/washers, I took my time to tighten them as equally as possible and it still manages to leak I've even broke a few donuts overtightening from being p.o, I have a question though my girlfriends 87 camaro 2.8 has 2 metal gaskets right above the donuts flat surface facing the manifold that seals her leaks where do I find me some of them???? -_-

XxXChrisGXxX

iTrader: (1)

Ok Maverick did a compression check both dry & wet (oil) and here are my results..remember these are after I did hours of timing still believe it is the timing of the valves or leaky valves, when I pulled the heads I didn't check for leaks (Idiot I Am) and just pressure washed the heads and valves, then replaced them with valve seals, and put the car back together, because I did have old gaskets now I think it goes deeper into this idle problem possibly dealing with leaking valves.

1 - 143 Wet - 143
2 - 152 Wet - 152
3 - 95 Wet - 95
4 - 105 Wet - 105
5 - 105 Wet - 105
6 - 116 Wet - 116

Hmm.. It's obvious my idle is deffinitely linked with horrible compression on #3, #4, #5. So is the valve timing 1/4 turn 1/2 turn or 3/4 turn?

Maverick H1L

iTrader: (8)

I'd look at getting myself a pair of head gaskets if I was you. Well, that would be my first thought, but I see your top end gaskets are new. So, my second guess is a valve float problem. If you understand what valve lash is, you'll know what I mean when I say you have to get rid of it (clean your pushrods up REAL good first before you do this or you won't get it right... they need to be DRY and not greasy). After you have no play in the valve system (vertically lifting the pushrod out of the lifter seat, etc, NOT spinning it), tighten the nut another 1/4 turn, no more. I've verified this with my compression gauge as to be where the engine likes the valve settings.

Can't help you with the exhaust donuts, man. Wish I could, cause then I'd get rid of my leaks the same way. I've got another one at the rear of the catalytic converter as well (the ball and flange joint). All I can say is that there is some out there that are made of a similar material to the EGR tube to plenum gasket that forms to the piping. You also have to be careful of the nuts backing themselves out. Try locking nuts (I'm about to go there next but I have to replace a stud as well). And, finally, while you are dealing with the nuts backing off, you will, I'm sure, want to tighten them up at times. That's a good way to end up spending another $20 on another pair of donuts. I can't tell you how many donuts I've had split into 3 or more pieces because of that.

If you have that large nylon pipe running from the nipple on the top of your throttle body to the back of the intake (with the IAC pointed right straight out to the passenger's side of the car), you'll need to do some more shopping if it leaks. I'll let you know tomorrow as to what size heater and fuel hose you need, but I do know you need 2 hose clamps, 2 feet of the larger stuff, and about a foot of the smaller fuel hose, along with a 1/2" PVC 90* elbow and a T.

:edit: Saw your injector harness question. Each end of the injector harness, to 90, looked like this: (OOOO). Disconnect BOTH ends, and, using a DMM on the FRONT connector (balancer end of the engine), connect your meter between the first and third (XOXO) terminals. You should read around 4 ohms. Do the same for the (OXOX) other 2 terminals and you should get the same result or close to it.

Also, there are some inserts in the forming donut gaskets that fit into a recess inside the manifolds. These inserts CAN fit into the cast iron donuts, but it's a real pain. There are early donuts that have a bit of a dimple for the pipe flange on the bottom and are flat on top as well.

XxXChrisGXxX

iTrader: (1)

This is the gasket I Need!! Her car is an 87 Camaro and it came with this gasket what the freak.. can't find it anywhere it is deffinitely sealing her leaks..going to go try and buy some carbon material or Percy's XX to make my own..

Maverick H1L

iTrader: (8)

That's a custom job, using the early donuts I mentioned (mine came from an 84, I think, either that or an S10 with an early 2.8) with some high-heat gasket material sandwiched between the flat of the donut and the manifold.

I'll look around in my garage tomorrow for my "replacement" idle air inlet pipe as I've been busy with my dead alternator (which I plan to have fixed either tomorrow or Thursday) and my 91 harness swap.

Also, for the donuts, if you find that gasket stuff, I'd like to know where, as I've tried EVERYTHING to seal mine up. Cleaning the crap out of the donut, manifold, and flange, sticking high-heat copper RTV sealant between the parts and putting things together that way, and still it leaks. It doesn't help that I need a new passenger's side manifold, either, and the top bolt for the #5 cylinder drilled, tapped, and replaced (next time I get the head off).

XxXChrisGXxX

iTrader: (1)

I've heard good stories about Percy's XX Create your own gasket material, it's a carbon material sheet 10x10, google it I'm going to try it on mine, but first settling this crappy idle going to tear it down one of these days this month.

FireInMe17

My 90 3.1L idles around 1000 rpm......thats the lowest that ive been able to get it smoothly tho too, i have all new intake manifold gaskets, and i just cleaned my IACV and throttle body, i sprayed carb cleaner on all the vacuum lines that i could see and get to and the idle speed didnt change at all, reset the computer too. I have noticed that when I seafoamed it smoke came out of the same spot that XxXChrisGXxX is worried about his gasket, could that also be my problem? Ive been trying for so long to get it to idle correctly, the car sat for 4 years...

2_point8_boy

Based on the readings that you have from the compression checks, you have multiple cylinders with poorly seating valves. Maybe they are burnt, or maybe they are misadjusted. At this point, I would strongly suggest that you remove the heads have the valves done, and re-install.

You definitely have a problem with #3, as it requires 90 PSI to fire a cylinder and you have barely that. Your compression is all over the place, so there is no way you had a steady needle with your vacuum gauge. Only accurate information helps us, man.

gfc

i have a problem, my 1987 camaro rs alternator is missing a screw and it shakes at idle. its missing the screw on the left side. any suggesions what screw it is?