88 2.3 running very very rough

rustyoldjunk · 09-03-2008

i just bought a very nice rust free 88 2.3 auto lx convert with low miles one owner.it has a new top,the head has been redone,its a very clean car.they had the head rebuilt then thought they would put the intake back on without gaskets.it will barely start (i dont know if it had this same issue before they had the head rebuilt),then when it does it wont idle most of the time and runs very very rough,like its running on two or three cylinders.i havent had much time to mess with it yet.i tried the easy stuff first,cleaned and tried changing plugs,the cap is new,the rotor isnt but its in good shape so i cleaned it and put it back in,then tried changing plug wires,even tried blocking the air intake(that made it worse,would barely rev),none of this helped.i will get back to it in a few days i hope.any suggestions or ideas? (i know i have to get in there and get new intake gaskets on it but i am tring to see if there is another issue causing this condition,so i can get to it while im at it)

b_chandler · 09-03-2008

Fix the big problem first. The vacuum leak you've got from not having an intake manifold gasket is severe enough to mask any other problem you might be having.

It's like saying I have a flat tire but I'd like to know what else might be causing this vibration and poor handling.

rustyoldjunk · 09-04-2008

b,i know what you are saying but tell me this,is there a sensor in the intake that tells the engine its getting to much air and would cause a flooding condition ? because in spite of the lack of gaskets the engine is flooding itself out badly.

5.0Stanger · 09-04-2008

Is there a VAM (Vane Air Meter) between the airbox and the throttle body? If so, that's what tells the EEC how much air is entering the engine. You cannot have any un-metered air leaks in the intake tract. That means, no vacuum leaks, no crankcase vent system leaks, no loose clamps, etc. Anything like that will affect the way the engine idles. If you have an intake gasket leak (or lack of a gasket), it's just the same as having any of the aforementioned leaks. You'd have a MIL on on the dash, if there was a big enough leak. Unpluging the VAM will set a code as well, causing the MIL to come on.

I'm working on a similar problem, with my '93 dual-plug car. Only at idle and in gear, does it run rough. I'm sure there's a little power loss, off idle, as well. I plan on checking the resistance of the plug wires. I'm sure they're a little worn out. Each time I've tried to pull the wire, the plug terminal stays on the plug. At the same time, the wire is in my hand.

b_chandler · 09-05-2008

That model is speed density. No MAF/VAM

The O2 sensor keeps reporting lean because of all the extra air that's getting in unaccounted for. That's why it's pig rich.

So in truth, It's not in spite of the lack of gaskets, it's because of them. It still amazes me that it even starts

5.0Stanger · 09-05-2008

If it's a SD system, it sure won't like a vacuum leak, like was said before. I've heard you can get away with no exhaust manifold gasket, but not the intake gasket.

mg man 75 · 09-05-2008

Also check the timing belt timing. If they would leave gasket off. Maybe also got the belt timing off also.