im stumped

[dumbluck2]

how can i have a dead cyc with low compression? with no smoke an no back fireing ex? just ruff idle! i mean its geting good spark but when you pull the wire off there is no differnce in the motor some one plz help! i also changed the injectors around didnt help.
things i tried.
replaced the spark plug #1
changed out the injector with cyc #5
put a lil oil in the #1 cyc to see if the compression will go up went up like 5psi
took off valve cover then turned over motor all lifters seam to be ok.
did a leak down on the rad seam to have slow leak donno where!
so i donno the cyc not geting air? reminder thats the cyc that had the blown gasket! an also whats the compression supost to be on the motor? im going to tri it with a better gage mines real old lol.

[Rolm]

I had the same on a 3.3 Grand-am. The shame was the car was perfect with the exception of Cyl. No.1, From what you have said it sounds like a worn or craked piston rings. The rough idle will get worse and the power will drop like a rock from 0 to 30 km after that it will seem to run ok, but in fact it is not. I talked to a engine builder and what they do as quick fix is pull the head off and drop the oil pan, push the piston and rod from the bottom, replace the piston rings with new and re-assemble and there you go, a cheap and fast fix. That is the way 90% of the engine rebuilders rebuild engines. So when some gives a quote to re-build your engine for around $1800 that is what you will get. Time to scrap or do a quick rebuild as above. later

[harmankardon35]

Maybe headgasket with the slow leak in the cooling system??

[dumbluck2]

i just replaced the head gaskits theres nu bubbles in the rad

[harmankardon35]

Ive personally seen this in many 91-99 toyota small engines...problem was the oil holes in the skirt of the pistons would clog up with sludge due to wrong oil viscocity or poor maintenance (not changing oil) and eventually the oil control ring would seize up, and by that time the compression rings had a fair amount of damage. This is when they start to smoke blue on start up. Next step most DIY'ers would take is to add a bottle of "no smoke" additive...only making the problem worse by complelty clogging the oil passages. 5 psi more compression after adding oil to a cylinder is pretty normal. If it jumped 20 or 30 then i would worry...but if its only 5 that means theres not alot of wear for the oil to temporarly seal up.