ok... its a 5 sp sohc 2.0l 96 neon we put the car engine back together... new head, new gasket, water pump, cleaned the manifold... cleaned the throttle body, new wires and plugs... the piston in cylinder one is pitted slightly on two sides... so it has a little lower compression.... C1 = 150, C2-4 = 180... the problem is that number one runs rich... it fouls the no 1 spark plug... we tried a higher heat ranged plug, and it fouled that one too, but it took longer... we are out of ideas why the no. 1 cylinder is running rich... we need to replace the exhaust and the up/down stream O2 sensors and the cat.. but we don't want to because we don't want it to get messed up by the engine.... the injectors are fine... we listened to them all... and even switched the 1st and 2nd injector.. and the first cylinder still fouled the plug.... i guess i could keep going higher with the plugs buti have no idea how high i can go?

any ideas what i can do? what i can check? anything? we have been throwing money at this thing left and right... and if it does come down to that i prolly have to get new pistons and bore the block.. how much does that cost... i have to drive this car from pitt to milwaukee, in a month... so i need it to be ready... please... any ideas would be greatly appreciated

 

hmm..the neon guys dont seem to be jumping at this one...perhaps a smaller injector?

tell you brother to "call bob".

 

You need to do a differential compression check/leakdown check. Where you apply a given pressure and see what the leakdown percentage is. You also have to check for air leakage into the block (open oil cap), into the intake (open throttle boby), into the exhaust (listen at the pipes). You do this with the air pipe to the throttle body off and the throttle mashed.

Dpending on leakage % and leakage locations you may find your problem. The other possibilty is actually a bad cam lobes. The intakes should all be very close to the same lift. To get one cylinder to vary 17+% on only a couple of dings would not be very realistic. They would have to be craters and you would not want to use it again. However if the intake lobe was bad you would not be getting enough air into the cylinder and thus RICH!!!

Did you try adding a little oil when doing compression checks (1 teaspoon). Any differences noted with this?