Hey guys, my TJ has been exhibiting a few driveability problems over the past week and I was hoping that I could have some assistance please.

Symptoms: at about half to full throttle acceleration, it will sound and act like she's starving for fuel. That is, the car will lurch, accelerate smoothly, lurch again, accelerate smoothly etc. If I plant the throttle, it will lurch a bit, but eventually accelerate as per normal. Annoying when trying to overtake. Driving gently with the revs kept at or below 2,000-2,500 rpm, it is mostly fine. It will cruise on the freeway at 110kph without problem, although it does lurch a little on long hills at a steady throttle.

Other info:

Car starts ok as usual and mostly idles fine (gets a little rough at times but shift into neutral and it smooths out and does not come close to stalling) Auto shifts ok. Fuel economy has not suffered at all.

A few causes I have considered:

Bad fuel - I have been using E10 for well over a year and I suspect it could be the main culprit. Last week, I filled up with Shell V Power 98 in the hope that I would see some improvement. I have, but the problem still exists.

Spark plugs - All 6 were replaced with platinums about 1 year or so ago.

Oil/Oil & Air Filters - changed earlier this year.

Fuel Filter - never changed, could be clogged with sugar cane? I can change this.

Fuel Pump - could be stuffed? Easy to change this myself if I buy the part? Access beneath rear seat I assume.

Oxy Sensor - never changed but as stated above, fuel economy is unaffected.

If anybody else has experienced this and/or you have a cure your help would be much appreciated. Thanks

What about the distributor? Its exhibiting the same symptoms as if there are water in the distributor cap. I have had that happen after an engine clean.

Sounds like classic Distributor issue, coil inside starts to break down and will create pretty much your exact issue

I was gonna say spark plug leads.

+1 for distributor. Try a new rotor arm and even a cap if the points are burnt/worn.
Had a similar prob but worse when it was cold.
Changed both of these and runs like new.

i would try the cheeper option of changing the fuel filter first them try the dizzy. The fuel can flow ok at low revs but cant quite flow hard enough under load??

Perfect thanks for the input guys. Yes under steady throttle the car struggles, surging and carrying on, but if I floor it, it will eventually accelerate smoothly. I do occasionally give the engine bay a hose down so the distributor could be the problem. Will check out both it and the fuel filter and report back. Cheers

I had the exact same issue with my old volvo. Had to replace the spark plug leads and distributor cap!

Cool as, I'll change the leads and the dizzy cap/rotor button this w/end and see if that does the trick.

Checked the dizzy and it was in what appears to be perfect condition. Rotor button had a little carbon build up so sanded it with 2000 grit. Leads showed no signs of deterioration but I did discover that the tube seals are leaking oil onto the leads (not yet into the spark plug chambers though). If I watch closely, I can see a tiny bit of oil seeping out onto the front bank's rocker cover from one of the chambers. Checked the dipstick and there is plenty of oil. Unsure whether that is causing the performance issues??? but it's something else to fix. Anyway, put in some Nulon Total Fuel System Cleaner and hopefully she will make it to this weekend where I'll definitely change the leads/plugs.

Interestingly, Ken-L experienced the exact same problem and his car only had 43,000km on it. I've sent him a PM.

http://www.aussiemagna.com/forums/showthread.php?t=71848&highlight=

I fitted new Bosch Platinum Plus plugs (part no. FR7 DPX $35.90) and Bosch Super Sport leads (part no. B6158I $92.95) at the weekend and the car is running better than I remember before it starting playing up. Smooth and very responsive. The plugs were pretty charcoaled, and the leads were the original Mitsusishi items, so she should be good for a while now.

Thanks

I own a tj 2001 magna! after just reading your post its inspired me to add this post! today i was driving at 80kph, the car had the fuel gauge on just above empty (just hitting reserve!) and the engine completely shut down. on start it would continue to turn, but no firing, so i towed it to my mechanic! everyone thought it had just ran out of fuel so put 30 litres of bp 98 octane premium! it started st8 away, but was splattery and noisy from engine ( mainly cylinders! ). we put a new fuel filter/ lifter additive / fuel system/injector cleaner! on the drive home at about 3000rpm it would splur and splatter and would not accelerate but smooth on low revs so I babied it home we started thinking fuel pump or ignition leads, after reading this im convinced its the leads and plugs thanks. still does not explain why engine completely shut down whilst driving! i looked into it a bit more. the other day i put 20 of unleaded at a servo where a fuel truck was filling the tank! (big no no ) at the bottom of every servo underground tank its the law that a certain amount of water is keeped on the bottom to allow for expansion! when a truck fills it it mixes condensation with the water and mixes all the fuel with the water ( UNseperated ) so i got more water in my tank than i wanted. also i only ever put 20 30 fuel in here and there (mostly premium rarely unleaded) which is also a big no no. it strains fuel pump / filter and collects more and more water in tank over time! today when i thought i still had " heaps of fuel left " ( 5 litres ) , it was all WATER......plus also the spark plugs and leads are ****ed ( maybe water in distib...) so ill follow you billy and replace my leads and plugs see how we go!