Hi everyone,

This is my first post, I Like to read as much information as possible before asking a question and I hope I am not causing a bother by asking already asked questions. I have been through threads but thought I would finally make a thread with my issues. Please be nice!

Ok,

As title says I have a rough idle like its missing slightly, lack of power in second it doesn't throw you back it just slowly winds up. It pings on acceleration and smells rather rich. I have changed to 98ron and it only makes a mild difference. This has been happening for quite awhile and this is what I have done:

New vacuum lines
pcv, throttle, Intake are squeaky clean and maf gets cleaned too
A 2nd hand maf from a far lower km 3.5l magna (made no difference)
New coolant temp sensor
New o2 sensor
new leads
cap and rotor changed
New plugs
fuel lines flushed with a motorvac style machine with new filter (they showed me a fuel sample which was pretty rank through the filter though tank showed clean fuel.)

Have pulled the injectors, soaked them and pulsed them forcing carby cleaner through them and this made the car idle $hithot for about 15 seconds then back to normal roughness. The amount of crap that was released from soaking was astonishing, carb cleaner was a filthy brown with heaps of grit.

After replacing the o2, way before injector clean and motorvac, I was parked on a grassy mound at my father in laws which raised the front of vehicle about 45-50 degrees above flat, she run so damn smooth, so quiet and threw me back in the seat upon hard acceleration after doing that. When I got home to Pakenham from Tyabb the car was switched off and next day same problems...that was even before the ecu was cleared before returning home.

No codes have ever showed. I have had this car second hand from about 170000km and has now done about 265000km. Another mechanic checked out the tps and all was good but did point to injectors. THis is when I cleaned them then got the motorvac done.

I spoke to a mechanic doing my wife's Renault service and said that if after cleaning the injectors she ran rough again, the car not wife ;), it was a tank out and flush. Today I trialled the "blow compressed air down the fuel supply line" from the hose to fuel rail and it did run a bit better so I parked it on that mound again but it is still pretty lame and pings.

Just want to clarify from the experts here what the root cause is. The magna never gave me any issues in the past but I cant stand it anymore. I used to get at best 7.6l per 100km (yes you read that right) going from pakenham to costco docklands but cannot achieve better than about 9.6l taking it easy.

:hmm:

ATM I am cash strapped and enjoy doing things myself but there is a time that the experts will need to intervene and correct the issue. I really like the car and want to run it till it dies a natural death...

Thanks for taking the time in reading :0)

Firstly. Welcome to the forum.

Sounds like your drama is definitely fuel related.

Have you had your fuel pump checked for pressure and flow rates?

I would get the injectors ultrasonically cleaned. Many workshops can provide this service for you.

Sounds like one or more is leaky or the spray pattern is not right. They need to spray a superfine mist, not squirt the fuel in.

Hope this helps you get your TH back to the way it should be.

It does sound fuel related, though you've covered the most likely things. I agree with mudfish re ultrasonic injector cleaning, and possibly there's a fuel pump or regulator issue. Understood re cash situation but I would recommend swinging a bit further north on your next Pakenham to Docklands run and dropping in to see Mal at Mits-Fix for a diagnosis... could be cheaper in the long run than replacing everything in a process of elimination.

Thank you Mudfish and Ensoniq5 for you feedback. I will pull the injectors and have them cleaned. A place here quoted 20 bucks an injector including o-rings (i already have those 1c parts in my grab kit) which i think is a bloody good price. A fuel pump is under $30 from ebay so that is cheap too. Where is the relay for the pump? is it in the actual housing? I have pulled the pump off before to clean to short hose and sock which was basically clean with only a minute amount of silver speckles.

I feel most relieved for the feedback, literally relieved. I will get the injectors done ASAP, of course I'll pull them off myself.

Once again very appreciative for the replies!

*Bows*:facejump::happy:

Make sure you let us know how you go with it.

Be interesting to hear what the spray pattern/condition of the injectors is too.

Pretty sure the fuel pump relay is under the centre console, if you lift out the facia you should be able to see it.

I will get them done within the next couple of weeks and I will post the results up for everyone to gander at. It will be interesting to see a before/after comparison.

Hmm, relay under centre console facia. I have had that off a hundred times to clean and only seen the auto computer and airbag computer.

Oh when I got the car the airbag light was always on suggesting the previous owners had done something when doing their dodgy dayton radio/microphone setup (most of it gone just the head unit left) so I just unplugged it. I wonder what they did...I wonder if there is even an airbag there!

If it is pinging severely, it's either a timing issue (too advanced, but unlikely) or its running lean.

It's either running lean because it's not getting enough fuel, it's getting too much air, or the mixture is not being controlled properly.

Not enough fuel
1. Perhaps pressure at the rail is below spec
2. Maybe the injectors need a proper ultrasonic bath
3. Maybe it's bad fuel and the tank needs to be dropped and cleaned/replaced and the filter changed again

Too much air
1. Vacuum leak (I know you have replaced vac lines)
2. Large intake leak - need to check the entire intake from the heads back to the throttle body
3. EGR stuck open?

Fuel mixture control issue:
1. MAF from a wreck could well be stuffed. Need to swap with a known, good MAF from a working car, not an unknown wreck
2. ECU - check under the front passenger side carpet for evidence of heater core leak and ECU damage
3. A myriad of sensors/valves could have failed - MAF, EGR, TPS, crack angle sensor etc etc

Is it possible two plug leads have been inadvertently swapped?

Take it to MitsFix. It wl be cheaper in the long run than replacing a bunch of parts.

Hi flyboy,

Just to let you know, i believe the heater core had been repkaced as there was evidence if coolant on passenger kick plate, underkay smelt damp like glycol but nothing has happened since I have owned. remember, it ran awesome once i had cleaned injectors but only for about 15 seconds. Revving it with my thumb from throttle body. And yes, if ultrasonic doesnt work it'll need a tank drop. As for the upper plenum, dont hear or feel any suction leak but they can twist/ warp from being aluminium, when i undo it to get rail off ill gasket seal it. Ill also try those e3 plasma spark pkugs, if cheaper than brisk. The e3 have to be sent from america. Still waitibg on brisk to give me price. Other wise ill get bosch platinum iridium infusion. Reason i replaced some of those parts was because i worked atbosch in dandy for awhile so why not take advantage of staff discount :woot:

Have suspected crank angle too, thats the on in the dizzy right? I keft it with a cover on for a month and had to pull dizzy apart and use ekectronic cleaner to remove corrosion. it ran better alnost perfect but still point to injectors. Shoukd never have used united fuel continuosky!

When rectfied ill never run below 95 again. might even get a vilo chip!

Cheers

Left car ourside with cover on for a month...just to clarify

Volo chip. Im terrible at touch phone typing

The crank angle sensor is at the other end of the block, near the belts, the one in the dizzy is the cam angle sensor. You also mentioned sealing the plenum, I would avoid using any sort of sealant at the junctions of the TB to plenum and plenum to manifold, you'd be better off grabbing a couple of new gaskets if you are concerned about leakage. At this stage I reckon you're right to get the injectors cleaned, at that price it's worth doing anyway. If it doesn't fix the problem at least that's one less potential culprit which should make it easier to diagnose. Failure of the coil is also a possibility, especially considering the history you mentioned, but I'd wait and see on the injectors or get a reliable diagnosis before swapping the dizzy and coil as it's a bit of a pain and potentially unnecessary.

Re the fuel pump relay, I've not actually needed to access mine and can't give any more detail, I'm just going by where the plug is shown to be in the configuration diagram. It looks to be a standard 4-pin relay, shouldn't be too hard to spot if its anywhere in that neck of the woods.

Ensoniq5,

That c.a.s seemes to have been changed since it was.and still is all new and shiny looking, even the wiring. But that could jusr be the nature of that side of the engine being away from most of the heat/dirt or oil collection area if you know what i mean. But then again the cruise pump looks fairly new too. Yes i have looked at new distributors but almost blew an "exhaust valve" at the price but then again 265 new might not be too bad unless it was a pointless exercise as you stated. Regardless of having a certiii in electronics i would have no way of knowing the coil. Is fully working apart from a strong spark on every plug tested a diz end (with thorough shocks to fingers).

I will be starting a new job on monday and will give that needed cash to do the maintenance. Don't even need to drive there, it's so close the wife can drive me there and back! So i can wait for another plenum gasket to arrive too!

Good thinking 99. (ensoniq5)