meadams314

Recently my '92 DX has started sputtering/misfiring at low rpms after it's warmed up. It'll start and run just fine when cold, but once it's warmed up, and has been driven 10-20 minutes is when the problems start. I'll pull up to a red light, and right as i'm just about to stop it starts running really rough, feels like it's on 3 cylendars.. If I come to a full stop it'll bounce around, sound like a harley and stall. It'll start up again, but it's a hard start and seems to be running on 2 or 3 cylendars at startup- give it gas, and it'll sputter faster untill it catches and rev's up... once it gets down to a certain rpm, it'll sputter and misfire again. It was throwing code 43 (fuel system) which many have said is typically a primary O2 Sensor. I put in new spark plugs and a new O2 sensor... the car seemed to run a little better, didnt die at a stop sign and when i pulled into the driveway it idled roughly, but didnt sputter. Till I revved it up and let off the gas... sputtered, fired 3-5 times and stalled. My next guess was to check the distributor or maybe the IACV.. HELP! haha

newtron63h

IAC is a definite possibility, since its only at low rpms vacuum leak is another possibility. throttle body being dirty could ause that.

meadams314

I was leaning towards the IACV... but the way the car acts just doesn't sound right for an IACV. It runs perfect on a cold start.. then misfires and sputters at low rpm once warm. AFTER letting it sit for a few hours and it's cold agian... it'll start up and sputter again untill i rev the engine up, then it'll catch and idle/run just fine till it warms up and start sputtering again. What could cause it to sputter and idle untill revved up after it cools down? Also.. the car burns oil and i found oil in the spark plug holes when i changed them. Found some gunked up oil in the coolant resevoir as well. Could a headgasket cause problems only after being warm? We just changed the headgasket a few months ago... it has overheated once or twice since then, but these problems started before the overheating.

Also, once it's warm and running crappily, even revved up it'll still randomly misfire and backfire, even at higher rpm. at 3000 rpm, it'll sit there and pop/miss totally randomly, no apparent pattern or anything to it.

And- after replacing the primary o2 sensor, the CEL stopped coming on- still runs like crap though.

I'm tempted to make a video of how the car acts... it's got me stumped.

chicows18

vacuum leak would not cause that. In fact if you have a vacuum leak it will rev higher. IACV wont make misfire either. Check to make sure all injectors are working. You can do this by listening to them and making sure they are clicking. Then check you fuel pressure. If filter hasnt been changed, do that first. Also, a bad TPS could cause that. Check it by disconnecting it while the car is idling bad and see if as soon as its disconected it betters. Hope that helps.

meadams314

Cool.. i'll run outside and try some of that here in a few minutes. I didnt think a IACV or vacuum leak would cause anything like that, it's gotta be something with the fuel system, or gunk in the combustion chambers or something... cause it still acts up after it's been cooled down, then stops once you rev up the engine....

christian7750

Could be a bad distributor?

newtron63h

yup, more info helps alot. not the iac, not a vacuum leak. i would put a fuel filter on the bottom of the list. that would be more noticable at high rpms and get better the lower you go. tps is possible, map, fuel pressure regulator, injectors,

i really wish everyone were born with a 5-gas analyzer. if you had one you could EASILY figure this out and narrow it down to a couple of things.

let us know how those tests work out.

Ya Digg

I think code 1 is supposed to be o2 not 43 but im not sure.

meadams314

Right, there is a seperate code for O2 Sensor... however a bad O2 sensor can also trip a code 43. After replacing the O2 Sensor the CEL stopped coming on.


Injectors seem fine, haven't gotten to the TPS yet, but i'm starting to think the headgasket is shot. The other night I went up to the store, and it ran fine all the way there. Once i started the car to come home again it chugged and sputtered, didnt want to start... after 30 seconds of driving it popped and caught then ran fine.. even idled fine. However there were massive amounts of whitish grey smoke coming out of the exhaust. Checked the oil today and it looks odd- kind of greyish and thicker than normal, smells slightly like burned gasoline too. What I dont get, if it was a headgasket why would it only act up once warm? The oil almost looked like a O2 sensor tip after you've been driving with leaded gas......

davefromPA

Umm. When is the last time you changed your fuel filter?

meadams314

Fuel filter doesn't sound right for how it's acting... it's been a while though so i'll take a look at it.

Noticed the oil on the dipstick looked odd so i changed the oil, came out grey and pretty nasty looking, put some in a glass jar- don't see any water/antifreeze in it. There is some gunky exhaust smelling crap in the coolant reservoir though- gonna check the headgasket next.

jdmhondamotive

sounds like you and i are having the same problem, is your car running rich? cause with mine it will cut off because its dumping massive fuel into the chambers, thefore fouling out the plugs. my car had sat for 3 years before i bought it, im most def going to look in to o2 and a new fuel filter...im not sure if that is the problem but it might narrow it down. g/l

jptyper

Start by trying the cheapest way first. Replace the spark plugs and wires first. I had this similar problem with my civic replaced the plugs and runs beautifully

christian7750

My car was sputtering because my distributor was bad, have you taken off the cap and check to see if there is any corrosion? Check the rotor or burn marks? If you know someone with the same distributor you can switch and see what happens

HellerDopeEK4

head gasket because there is coolant mixed with oil, this is why ur oil looks milky.. and white smoke is coming out of ur exhaust pipe...its probably over heating...my .02 cents

newtron63h

head gasket. or possibly cracked head. honestly i dont mean to scare you but a crack in some metal fits the fine when cold but crappy when warm description. cylinder leakage test it. it will let you know for sure whether its a gasket or crack. CLT it cold, then warm it up and do it again.

meadams314

That's what I'm worried about. The white smoke is gone, but now the radiator/block are full of straight water, and i noticed steam coming out when it was 80 degrees outside. It's also been losing coolant when I drive and I couldnt find any leaks or bad hoses. Between the oily crap in the coolant reservoir, and greyish oil.. man I hope the block's not cracked

meadams314

You know, when i changed the O2 sensor, it was pretty black which would indicate running rich. Also after the car's been acting up, i can turn it off and let it sit for a while and it'll sputter on a cold start, but after i rev the engine up it runs fine- like there was too much gas or some gunk in the cylenders or something, and it runs fine once it's cleared out. Still leaning towards headgasket though- exhaust smell from the radiator, oil in the coolant reservoir and watery oil. God I hope it's not a cracked head, this car's not worth buyin a new head for. haha

meadams314

Took the head off today and inspected everything.. couldn't see any cracks/chips/anything that might cause problems. The headgasket looked pretty bad though. It was replaced around a year ago, but it's overheated 5 times since then- had holes eaten into it around the water jackets... and a small chunk missing around one of the oil holes (i guess they're called oil holes. haha) Also found oil running from the oil hole to a spot above one of the water jackets. Gonna put a new headgasket in.

My question is this- I'd like to do the piston rings while the head is off (car burns oil) but i'm not too knowledgeable about this. What kind of work has to go into it to do it correctly? I've heard talk of having the cylenders honed by a machine shop.. even of boring the cylendars and using bigger pistons. What's the cheapest easiest way to go about piston rings?

newtron63h

ok, here it is.

when changing rings you have to have the cylinders honed. honing basically makes scratches in the cylinder walls in a specific pattern that 1: makes the rings wear into the shape of the cylinder. and 2: makes the rings rotate in the cylinder.

there are a few ways to do this, each being more expensive. each being a better option for longevity and peace of mind
1) you could trust that your block has no issues, everything is flat where it should be, round where it should be, in line where it should be.....etc and just get a honing brush and do it yourself. install the new rings and reassemble.

2) let a shop rehone, they might measure the cylinder bores to make sure its within wear specs....but thats probably about it. then they hone it and reassemble just like you would, although you should get some kind of warranty from them.

3) take the short block to a machine shop who will then disassemble, inspect and measure everything(bores for wear and out-of-round and taper and being square to the mains, main bores for straightness and roundness, crank for straightness and roundness of the journals, deck for flatness and square to the mains. roundness of the rod bores.)
then they fix any issues. in fact they will probably give you back a straighter, flatter, rounder, truer block than what came from the factory. they can reassemble it for you, or give it back to you apart for reassembly. oh and they will also clean the ISH out of the thing before they start any of that stuff too. they will hone the cylinders AND they will fit the rings for you so if you want to assemble it yourself all you have to do is lube the parts and assemble it. they will also fit bearings for you.

one word of advice though, for main bearings and rod bearings, DO NOT put any kind of lube UNDER the bearings. clean the main and rod caps as well as the saddles with acetone or sumthin similar and instal the bearings DRY, THEN use assembly lube or oil to lube the journal side of the bearings.

no idea on prices for said work.......but again you get what you pay for. another option with the machine shop is to have them balance the bottom end for you.

anymore questions just ask, ill try to point you in the right direction.

also a big one that machine shops will usually do is magnaflux all the iron/steel parts to make sure there are no cracks.

meadams314

Well.. everythings taken off- haven't gotten to taking the pistons out yet (working on the car on my days off from work). I can't believe it's a hundred bucks for some new head bolts... damn. I know it's not recommended to re-use factory head bolts, but they're not torque to yield, and the car's only got 108k miles on it... guess i'll shell out some more cash. This job keeps getting more expensive. haha

jgc731

i'm interested to see how this turns out. i'm experiencing similar problems. i sputter during low rpms. when you give it some gas it feels like the power doesnt kick in maybe a full second delay.

ive checked the timing (OK), replaced the spark plugs, replaced the fuel filter, replaced the distributor rotor, checked the spark plug wires (OK), checked fuel pressure (OK)

stumped myself, i can guess that it might be:
fuel injectors
fuel pump
ecu
tps

good luck, ill follow up to see if you've done anything that fixed it.

newtron63h

classic vacuum leak symptoms

meadams314

Is it just a rough idle, or misfiring? Once we got the head off, my headgasket looked like it was in bad shape- that combined with the oil/antifreeze mixing together makes me hope it was just the headgasket (possibly from re-using head bolts when we replaced the headgasket after the car overheated last year) but I have my doubts- why would it only act up once the coolant hit normal operating temp? But then again, if you started the car and turned it off right away, it'd have a hard time starting and act up a little upon re-start. Obviously haven't gotten the car running yet to determine if that was the problem but... I also checked/replaced everything you did other than the fuel filter/spark plug wires, and nothing fixed it. O2 sensor made the CEL stop coming on, but the problem didn't go away. We're doing the piston rings to fix another problem- the burning oil.

meadams314

Was removing the rod bearing cap on cyl. no. 1, and this semicircular piece of metal fell out of somewhere, didn't see where it came from, and can't for the life of me figure out where it goes..


It looks like it's broken in the picture, but it's not- that's just dirt/grime.

There's also what looks like a part number on the back-


It's about the diameter of the cylinder wall minus the sleeve, and I can't see any possible spot it could have come from.. what the hell?