1fz-fe running rough
Submitted: Friday, Jun 13, 2008 at 18:19
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newlux
I've had this 80 series for about 3 months, about 2 months ago I had an impco lpg system fitted. So far it has been running great on gas.
Last Friday it started running rough on both gas and petrol, as though it has dropped a cylinder. After a bit of research I realised that you should run colder series spark plugs when running lpg, so I fitted NGK Iridium plugs. Then the engine wouldn't start at all. So I pulled the plugs back out rechecked all the gaps and refitted them, still no start. I put the old plugs back in, still no start. I then called out NRMA who couldn't diagnose it either so the next morning it was towed to the auto electrician.
He worked out the problem as the air flow meter and after having it reconditioned i finally got the car back today. The air flow meter only fixed the problem of it not starting not the rough running. But it is still running rough, the same as it was before I changed the plugs. The auto elec reckoned it was just a coincidence the air flow meter failed while i was changing plugs.
Does anyone have any ideas? It is rough at idle and under acceleration?
Any help would be appreciated.
Reply By: Splits - Friday, Jun 13, 2008 at 20:15
Friday, Jun 13, 2008 at 20:15
I have had gas powered cars since 1988 and have never had to put colder plugs in any of them. The colour of the standard ones has always been normal.
How old are your plug leads? If they are years old then they will probably fail a resistance
test and should be replaced. Disturbing them to change the plugs could have made them worse.
I would imagine the car has diagnostic code lights on the dash. They could easily show something so if you can't read them, see if you can find someone who can.
These type of problems are usually electrical and there are a few things that can cause them. If you like working on your car and don't have a workshop manual then get one. You will also need a good quality multimeter of a type that will not damage some of the parts you will have to
test. Good ones are usually upwards of $200. The factory manual covering the engine and its electronics is by far the best but a non genuine one will usually do. They will list step by step procedures to trace problems like this. The tests on each individual sensor or circuit are fairly simple.
Brian
AnswerID:
309749
Reply By: newlux - Friday, Jun 13, 2008 at 20:40
Friday, Jun 13, 2008 at 20:40
Thanks for the replies.
I have tried to get in contact with the lpg installer this afternoon, but didn't get a call back before they left for the weekend, so i'll leave that avenue for monday.
The leads are 5mm spiral core leads which look to be in pretty good condition but I will get out the haynes manual in the morning and
check the lead resistance. The auto elec also noted that the leads looked good and also the distributor cap and rotor.
I have no idea when and if the valve clearances have been checked, I am running a flash lube kit. After I
check the leads I might get the valve clearances checked.
Mick
AnswerID:
309760
Reply By: Member - Bucky (VIC) - Saturday, Jun 14, 2008 at 10:33
Saturday, Jun 14, 2008 at 10:33
Question.............what do the Gas Specialists recommend you use ??
.........................
And what condition is this list in ?
Plugs,
Spark Packs/Distributer cap
Leads
Any dead shorts, anywhere, what power is getting to the plug, maybe a broken wire, ( hidden )
Waterproofing, seals ect
Had a Commodore, ( big deal ) but I used to run Bosch HR7DCY , gr8 plugs
Now we have Platnimum ect,,,,so high quality plugs will pay for themselves
Cheers Mate
Bucky
AnswerID:
309862
Reply By: newlux - Saturday, Jun 14, 2008 at 18:02
Saturday, Jun 14, 2008 at 18:02
I've been going over truck today with a multimeter and everything seems to be o.k.
The plugs are new, I have done resistance checks on the leads, the distributor, the primary and secondary resistance of the coil pack, the pick up coil, and everything is within the limits as outlined in the haynes manual.
One of the lead seals does not clip in tightly onto the rocker cover and another of the seals is starting to break up, but apart from this the leads are in good condition. Could this be causing the problem.
I cleaned a up a little bit of corrosion on the rotor and distributor cap contactors, but the car is still running rough. It is rough at idle and under moderate acceleration. If accelerating hard it will cough for a few seconds and then smooth out.
Ant ideas?
Mick
AnswerID:
309956
Follow Up By: Debbie_115 - Sunday, Jun 15, 2008 at 21:11
Sunday, Jun 15, 2008 at 21:11
Hubby now
home and after my great explanations in past reply (no. 9 I think) he says its the air intake pipe directly above the rocker cover there should be a foam rubber sock on the air intake -
check for holes and wear because ours had similar problems and it had a hole which once replaced fixed the problem. And as said in early reply stubby holder fixed it!
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