Searched and have a general idea of things that can cause misfires but i don't really want to try fix this through trial and error replacing a whole lot of different parts. Fair enough? '87 VL Wagon RB30E Manual, Standard engine(no mods) Ive got a regular misfire, every couple seconds on idle. Sometime twice in a row every couple seconds. Ive also noticed that the car will kinda 'bog down'? until around 2000 revs and kinda pick up noticeably. Car runs smooth with AFM unpluged (does this mean its AFM problem?) Have tried a spare AFM, checked both with multimeter and have correct settings (though on one if resistance is set correct, the recommended voltages are out is this a sign its buggered?) Tried spare coil. Fuel pumps arent noisy. Has half a tank. Have used contact cleaner on AFM and CAS plugs. Scraped corrosion off distributor brushes/contacts. Thank you for any help. And im not very mechanically minded either.

try moving the ignition leads away from any sensor wiring (mainly CAS) the car will idle fine with the AFM unlugged but it wont rev over 2000 RPM. it will most probly be an electrical problem/interference. check all your earth points

yeah i moved the leads away going to replace spark plugs on thursday when im free. really annoying

Ok i've done some more searching and i understand a vacuum leak can cause rough idles? and my heater hisses when i try change to anything other than windshield or feet. this means that its leaking right? possibly disconnect hoses? would this likely be the cause of my rough idle and bogging down until about 2000rpm?

Quote: Originally Posted by vanlowe Ok i've done some more searching and i understand a vacuum leak can cause rough idles? and my heater hisses when i try change to anything other than windshield or feet. this means that its leaking right? possibly disconnect hoses? would this likely be the cause of my rough idle and bogging down until about 2000rpm? This is exactly my problem. My idles rough every few seconds and it ****s me to tears. If I rev the car past 2000rpm it is fine and clears up, but anything below 1200rpm it's rough. My heater hoses hiss as well which pretty much indicates that theres a vaccum leak behind the controls. Everything in my engine bay it pretty good (connectors, sensors etc) so Im guessing that fixing the hoses should sort out the problem. I just havent gotten round to it yet. I'd buy a roll of new hose as well as I remember the old ones seem to go a little hard and don't make a tight fit around the nipple-like things they go on to. Once you've replaced the hoses behind the heater controls, you might as well replace the ones that go to the check valve. It's around under the dash near the controls somewhere. Let me know how you go mate. I won't be fixing mine until the weekend.

Quote: Quote: Quote: Originally Posted by vanlowe Ok i've done some more searching and i understand a vacuum leak can cause rough idles? and my heater hisses when i try change to anything other than windshield or feet. this means that its leaking right? possibly disconnect hoses? would this likely be the cause of my rough idle and bogging down until about 2000rpm? This is exactly my problem. My idles rough every few seconds and it ****s me to tears. If I rev the car past 2000rpm it is fine and clears up, but anything below 1200rpm it's rough. My heater hoses hiss as well which pretty much indicates that theres a vaccum leak behind the controls. Everything in my engine bay it pretty good (connectors, sensors etc) so Im guessing that fixing the hoses should sort out the problem. I just havent gotten round to it yet. I'd buy a roll of new hose as well as I remember the old ones seem to go a little hard and don't make a tight fit around the nipple-like things they go on to. Once you've replaced the hoses behind the heater controls, you might as well replace the ones that go to the check valve. It's around under the dash near the controls somewhere. Let me know how you go mate. I won't be fixing mine until the weekend. yeah ive only just started to look into it but from what ive gathered its important to have the same size and length hose. thatd take a bit to sort out i guess. do you know what size the hoses are and what i should be asking for when i buy new hose?

I couldn't tell ya mate. I'd just take a sample down to Bursons or the like. Ask for a long roll of the stuff.

injectors leaking? maybe causing flooding till it clears ?????

Quote: Originally Posted by Ratta injectors leaking? maybe causing flooding till it clears ????? do you reckon that could be it? sometimes after its been sitting for a while, maybe a day, it struggles to turn over, as if battery were dead and often will fail to start first time unless i pump the accelerator a little, could that be a symptom of leaky injector? i looked at vacuum lines in back of heater and 3 were unpluged, they were bit had it but i just insulation taped the ends and put on theyre working as they should for now

Quote: Originally Posted by vanlowe do you reckon that could be it? sometimes after its been sitting for a while, maybe a day, it struggles to turn over, as if battery were dead and often will fail to start first time unless i pump the accelerator a little, could that be a symptom of leaky injector? i looked at vacuum lines in back of heater and 3 were unpluged, they were bit had it but i just insulation taped the ends and put on theyre working as they should for now Yea **** thats the same with mine. Its like the battery is half flat every time I go start my car after work. If I had my car now I would be straight at it as bringing up this topic reminds me of how annoying it is Some original photos have not been recovered yet.