Prelude stalling problems
 

Recently I've purchase a 1991 Prelude SR, and I've changed the Air Filter/Spark Plugs/Engine Oil/Oil Filter.

I tried to change the fuel filter but the damn banjo bolt is torqued on way too tight. Before I changed those things mentioned above, the car was obviously losing power but it did not stall when I come to a stop. Now I am wondering if it's because I didn't/couldn't change the fuel filter that's causing my stalling problem.

Note: The car did not stall one bit when I drove it home from the sellers place. It only stalls now after changing the Air Filter/Spark Plugs/Engine Oil/Oil Filter but not the fuel filter because those bolts are torqued too tight, and probably will need to bring it into a shop for an Air wrench to take care of.

My theory is that now the engine is getting the proper amount of air and the right spark, but it's not receiving enough fuel due the old/clogged fuel filter that's causing the stalling problem.

Any other takes on this guys? :confused:

are are the spark plugs torqued correctly?
Oh and check the TPS sensor is plugged in. You may have knocked it loose or off when you were changing the filter.

Changing the air filter and plugs won't be the cause of, lack of fuel. PGMFI would automatically adjust for more fuel if needed. (Which i doubt you're needing more fuel anyways)

does it stall when accelerating/driving/cruising or idling?

Not so sure if plug torque could be the cause. TP sensor disconnected would set the engine light on

Yep, the plugs are torqued to Manuals Specs, the check engine light is not on while driving.

It only stalls when I slow down to stop or just to around 10 km/h. Other than that the engine is in fantastic condition. Starts smooth, idles smooth, runs smooth. I did notice that the idle is kinda low when its warmed up, only around 550-600 rpm, could it be the combination of the low Idle speed and the old/clogged fuel filter causing it to stall? Once again, the car did not stall when I drove it back from North Van to Richmond, with all the old plugs and filters.

Sounds like a vacuum leak somewhere.

along with vac leaks,
i'd be checking for air intake problem. More particulary, the idle valve (EACV) and the idle speed adjustment screw and air passage. Check base idle too.
If that dont work, i'd be checking valve clereances. looking for tight valves

Clean your IACV.

There's nothing wrong with the idle though, it doesnt even stall when i idle, only when I brake really hard

only when you brake? thats a big clue right there.

The brake booster works with engine vacuum, if there is a huge leak in the booster, unmetered air will get into engine causing it to be too lean and thus stalling it out.

if the booster's leaking, you'll have no power assist too, and have a hell of a time stopping.

when you rev it up and down in nuetral and let it back down to idle, does it stall?

Vacuum

nope, the brakes work fine, pedal pressure is correct and there is no loss of stopping power, and no it doesnt stall when i rev it and let it drop

this is really confusing i hope its not a serious problem. I really wanna get my fuel filter changed and HOPEFULLY that solves this problem lol.

^It's not likely to solve the problem, the symptoms do not point to a faulty/clogged fuel filter. It must have been a hose or something related to PGFMI (or whatever the fuck it's called) that you may have forgot to install or knocked off.

has nothing to do with the fuel filter at this moment in time. the stalling is due to a vacuum leak somewhere, and if it is stalling when you brake you should start by checking around the brake booster.

depending on which part is leaking, you can have a vacuum leak in the booster, and not have any pedal problems.

simple way to see if its the booster is to pinch off the hose to the booster with vise grips and see if it stalls.

any part of the booster that needs to hold vacuum and leaks while pressing the brake pedal will effect braking assist

correctly gapped the plugs?

I'm assuming NGK properly gapped them specifically for the B21A1 engine. Or at least a inline-4 engine, lol

^It's not likely. Save for platinum, you should always check your plugs. Even with platinum, sometimes the gapping can be off which will cause hard start/hesitation/loss of power.

Yeah I tried it and it actually didn't stall the car :confused: lol

i meant pinch it off, drive it, hit the brakes hard (or what ever makes it stall) and see if the problem persists

^ Ok, I poked around the engine bay, and to my surprise, there was no fucking battery clamp holding the battery down! I took it off my Accord and stuck it on, before I put the clamp down on the battery, it would seem to press against and probably pinched off some soft hose/tube behind my right headlight on any kind of braking. Now it only stalls when I REALLY stomp on the brakes, as opposed to before when ANY kind of slow-down to a stop would cause her to stall, and I also reassembled the air filter assembly.

Btw: I stomped on the brakes to a stop in 5 instances, all from 60-70 km/h to a dead stop, 1 out of those 5 times caused a stall, the other 4 didn't even cause a hiccup in the idle or engine. Before even a normal stop would stall it. Now could it be a clogged fuel filter?

Ok, I bit the bullet and bought an air wrench, and got the old fuel filter out. Now the problem seems to be resolved. :D