I couldn’t find anything that is similar to what I’m experiencing, but I replaced the components based on what I’ve read in other threads.
Whenever I start the car up, it sounds like I’m firing on 3 cylinders for a while until I get moving about 100 feet, then all power is restored. I tried replacing spark plugs, plug wires, fuel injector cleaner (I use this often enough already), fuel filter (replacing this actually fixed the situation but only for about a day, possibly related to an ECU reset?). I’m thinking about the oxygen sensor (91 LS) but I would think if it was a bad sensor, I wouldn’t be experiencing the problem once the engine is warm.
[QUOTE=N FUL FX;2317749]I couldn’t find anything that is similar to what I’m experiencing, but I replaced the components based on what I’ve read in other threads.
Whenever I start the car up, it sounds like I’m firing on 3 cylinders for a while until I get moving about 100 feet, then all power is restored. I tried replacing spark plugs, plug wires, fuel injector cleaner (I use this often enough already), fuel filter (replacing this actually fixed the situation but only for about a day, possibly related to an ECU reset?). I’m thinking about the oxygen sensor (91 LS) but I would think if it was a bad sensor, I wouldn’t be experiencing the problem once the engine is warm.
Any other ideas?[/QUOTE]
Since your problem seems to be when the car is in open loop (warming up), I would look into the fast idle valve first, then the iacv since they both work in conjunction of each other. When you first start your car it is in open loop (mechanical term) kinda like pulling the chock, so the computer uses the maf / or for our gen2 integras map sensor to rely on fueling but to do this it has to also depend on other factors such as the iacv and the fast idle valve . The fast idle valve pushes air into the throttle body while the map sensor is en-richening the fuel mixture to compensate for that extra air, this process will continue until the engine reaches a certain coolant temp then it will go onto a closed loop mode. If you want to try and fix this yourself you can take out the fast idle valve from the coolant lines and open it from the inside by loosening the two small screws then grab a semi long flat head screwdriver and turn it till it stops, don’t force it or you will break it cause it’s super old (you’ll know when to stop because it will bottom out) and so are our cars. Another thing you can do Which I wouldn’t recommend but a lot of people do anyways is swap out the throttle body and get one from from a 92-93 integra ls which does not incorporate a fast idle valve, but to do this correctly you will need to swap out some coolant lines and bleed the system out. Good luck and I hope that you don’t go and waste your money on a bunch of parts that your car may not need and rather us gather and help you as much as we can to try and solve this problem so that your da can run on all four every-time like it was meant to.
op, start by checkng for codes. regardless of an illuminated mil. always check codes first. if none, perform a power balance with the engine cold to determine if the problem is inherent to a solitary cylinder. to do this, it’s recommended to kill injectors rather than ignition. if the problem is not traced to a solitary cylinder, that tells you something right there. this is something common to all cylinders. you just narrowed down the possibilities by half. so it’s either air, fuel or ignition. start by checking fuel pressure. if that’s within spec, check ignition. you must use an HEI tester. these are simple to use and can be found at most auto parts stores for around 20$.
if you perform those tasks, and you haven’t yet started to smell the culprit, we’ll move further. report back please
and just to correct, da one, a single wire o2 sensor, which the op should have if it’s a 91, will very rarely enter closed loop. pretty much only under light to mid engine load. it is also not coolant temp that initiates closed loop, but rather exhaust temp. more specifically, the temp of the element inside the sensor. it needs to reach roughly 5-600* before it’s able to produce voltage. you won’t see that high of temp at idle, or very light throttle. this was the reasoning behind the heater element in a 3 or 4 wire o2 sensor. with a heated o2, the ecm can enter closed loop within about 30 seconds of start up on a stone cold engine.
Don’t worry about it you’re cool w me, and yes you are correct on that statement that the o2 is the one that heats up first, I just said that because the engines coolant temp heats up also since I was talking about idle air control valves and idle air valves so I was justifying my view of that particular topic plus half my brain was working as it was like 1 or 2 am. But that being so your are totally right and thank you for noting that, two heads are better than one right ? lol
Just read through your replies this morning. Whew.
There’s no engine-light nor code flashing at the ECU.
I’m unfamiliar with “killing the injectors” process and using an HEI tester. (I’m not a fan of acronyms :P) Can you elaborate? I was actually wondering if I had a faulty/leaky injector too…
kiiling injectors; well, first let’s startby defining the term power balance. when an engine has a dead miss at a particular cylinder, you can determine which cylinder it is by disabling combustion at each cylinder, one by one, until you disable the cylinder which makes no difference on the engines idle/performance. so let’s say you have a dead miss in the 3 cylinder. you start by disabling number 1 cylinder. (killing the injector is a means of disabling combustion in that cylinder. it just means to diaconnect the injector. another means of disabling is to kill spark. i don’t recommend this because when you have 20000v built up with nowhere to go, it tends to be hard on the coil). engine runs worse. you know that cylinder is not the cause of the miss. you reconnect the injector and move to the next cylinder. you do continue this until you find the cylinder that makes no difference when disabled. that’s the cylinder with the miss. that’s a power balance test. obviously you need to be substantially misfiring in order to perform this.
HEI stands for high energy ignition. it’s a term gm used for their ignition systems. pretty sure they patented the tester.
considering it happens for a very short period, on a cold start, i’d probably just start by seeing what’s going on with fuel pressure when this is ocurring. it’s a likely possibility, and it’s something you can view in that short window. and if anything, even just to cross it off
