gilly40k Posted February 17, 2012 Report Posted February 17, 2012 Hey I have a Toyota corolla ae92 it has the 4afc motor I have changed the carby because a backfiring issue but still remains what else can it be? The carby is a sealed unit u can't change air or fuel mixture I have a brand new muffler on it also new plugs new leads and new rotor button and cap i need help please Quote
gilly40k Posted February 17, 2012 Author Report Posted February 17, 2012 Do I change the intake manifold and exhaust gaskets as well? Quote
gilly40k Posted February 17, 2012 Author Report Posted February 17, 2012 Yes I have it said 5 degrease bftc Quote
gilly40k Posted February 17, 2012 Author Report Posted February 17, 2012 The igniton timing I have Quote
altezzaclub Posted February 17, 2012 Report Posted February 17, 2012 Burnt inlet valve will backfire too. When does it backfire? Idling? Accelerating? Over-run/downhill only? Quote
gilly40k Posted February 17, 2012 Author Report Posted February 17, 2012 Idle and when I take my foot off my peddle Quote
altezzaclub Posted February 18, 2012 Report Posted February 18, 2012 Do a compression test and see if one of the inlet valves is leaking back into the carb. Is this a sharp explosion "BANG" back in the manifold, of more of a "cough" as it misfires? Our R31 Pintara does it just as you accelerate again after trailing the throttle, so changing gear is a common time. It just gives a little cough as the throttle opens. I don't want to look at it, the car is worth nothing really, but the cost of buying something else to replace it will be... Quote
gilly40k Posted February 20, 2012 Author Report Posted February 20, 2012 There is no problem with my carb no back firing coming thru there just exhaust only Quote
altezzaclub Posted February 20, 2012 Report Posted February 20, 2012 Ignition timing can do that, give it 8-10deg advance and see if that makes a difference. Otherwise do a compression test to see if an exhaust valve is leaking. If it doesn't fire a cylinder it dumps that unburnt fuel out into the exhaust where the flame from the next cylinder fires it. So if a plug or lead or any part of the ignition circuit is missing a cylinder that might do it. Quote
Willis Posted February 21, 2012 Report Posted February 21, 2012 Do a compression test and see if one of the inlet valves is leaking back into the carb. Is this a sharp explosion "BANG" back in the manifold, of more of a "cough" as it misfires? Our R31 Pintara does it just as you accelerate again after trailing the throttle, so changing gear is a common time. It just gives a little cough as the throttle opens. I don't want to look at it, the car is worth nothing really, but the cost of buying something else to replace it will be... Twin spark CA20 Altezza?? Sorry for unrelated post. Quote
altezzaclub Posted February 21, 2012 Report Posted February 21, 2012 yep- Although I do have both coils firing at the same time. Interestingly, we checked plugs recently and the driver's side 4 were beautifully clean (the main ones) and the passenger's were black and crappy. So although they fire together the secondarys are not in a place where there is a good burn. (which is why the factory fitted them I suppose!) Since August its done two trips Orange to Armidale and back, and a trip up to the Queensland border... No problems at all, except a bolt came fractionally loose in the rear suspension and caused it to creak over bumps. ..and the UJ at the diff shat itself, but hey, it was free! Quote
Willis Posted February 21, 2012 Report Posted February 21, 2012 Can't complain about free cars! A friend of mine had one for a daily. Picked it up for 250 bucks i think. He just slapped some rego on it and bashed it around. He ended up sledging out in the wet, mounting a curb and landing on a large rock. The chassis was ALL bent up. Still drove it for months after that. The thing was a machine, just kept going and going. They run mighty lean :P Quote
gilly40k Posted February 23, 2012 Author Report Posted February 23, 2012 Ok so what I am going to well doing is! I paid for a new manifold carb recon emissions control hoses upper throttle cleaner helps clear cylinders I am just gonna go over bored and make sure I don't miss any thing replacing the catconverter and exhaust manifold with pacemakers should fix it Quote
gilly40k Posted February 28, 2012 Author Report Posted February 28, 2012 Ok I found the problem my emissions where dumping alot of its shit back in the motor so I have disconnected it and plugged it and drilled out mixture screws and cleaned carby with carby cleaner Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.