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*LMAO* Not firing on all cylinders! - Engine/Ancilliaries - The Lotus Forums Jump to content
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Chris89turbo

*LMAO* Not firing on all cylinders!

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Okay, this is funny to me becasue of this condensed version of my story. Bought a 1989 turbo last summer, and 10 days later I had a full hands on experience changing a clutch... Had to tow the car 2 more times in the next three months... Then sold it to invest in gold (great move by the way)!

SOOOOOO.. I decide it was a fluke & bought a 1990 SE 2 days ago with only 50k on it and took it out for the first time tonight (10 MILES), and HERE WE GO AGAIN!!! hahahaha

i get home, its running fine (has had a slight stall when first tapping the gas pedal since I got it), but after I shut it down, came out ten minutes later & fired it, its not running on all cylinders (I dont think.. not a smooth full running idle)... It basiclly runs consistantly, but "not combusting" fully.

I put a timing light on each wire, and have good current through the wire, and the timing looks good... I dont have any kind of raw fuel smell coming from the exhasut, so I am assuming this could be a lack of fuel into the injectors.

The gas in the car is almost a year old since it was sitting when I bought it, but it wasnt doing this when I got the car & took it home a few night ago, or tonight when I took it out. Will it hurt to run injector cleaner through it? I am going to drain the tank obviously, but what other checks would you guys recommend?

Chris

Kansas

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Change the spark plugs. My S3 has twice had a plug just suddenly decide it does not want to work any more. Even heating it on the gas stove and retrying would not work, new plug and away we go again no problems...

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I think I will agree that at the very least a minor tune up would be in order. Nothing overboard, just oil, filters (air oil fuel) and new plugs. This should eliminate a lot of potential questions. Also, I'm curious to know if there was a reason given as to why the car has been sitting when you bought it? Injector cleaner shouldn't hurt and will help break up any varnish that has accumulated on the injectors from sitting.

One more question, is the misfire only at idle or does it occur at speed as well?

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Good idea. I dont think it would hurt to do that anyways since the car hasnt run much in the last year.

Follow up: Yesterday (the day after this problem), I went out to start the car to move it into my garage, and it started up & ran fine again... Weird.

Changing plugs, gas & fuel filter (with some injection cleaner)... We shall see what that does,,,, I may even run 3-4 litres of some of that 100 octane super cart fuel through it just to give it a good clean burn.. I hope I dont get addicted to the performance of that fuel though. That could be an expensive habit!! haha

The oil is very clean... But I agree I will be changing that as well.

the reason the car sat for so long was that it was smacked in the front end, and the valance was busted off. No structual damage to the chassis or suspension, but its missing the entire front bumber/valance assembly so its not worthy to daily drive... The guy I bought the car from bought it at an auction like that & is 6'3" tall, so as soon as he sat in the car he said "not gonna work" and sold it to me.

The misfire is throughout all ranges... Its a consistant misfire

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I'm thinking a minor tune up along with some easy driving might clear a lot of that up. I would however strongly suggest inspecting the belts, in particular the timing belt. Having sat for a while, it's likely that the belts have begun to deteriorate. The timing belt certainly isn't something you want to take chances with, especially if you've priced the parts and labor (yours or someone elses) involved in "undoing" the damage from a snapped belt.

I would first be looking at the coil packs. There should be a plug going to them that receives voltage as well as the signal from the ECM telling each coil pack when to fire. Make sure this plug has seated properly, as well as all of the spark plug leads on the coil packs. Also if you have a manual, look up the coil pack test proceedure and verify your readings are within spec (you'll need an ohm meter for this step). It's possible that one of the coil packs are bad which can give similar intermittant symptoms. If you don't have a manual, perhaps someone here on the board can give you the proceedure.

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I will also recommend a timing belt change. Just went through one for the first time, it's an adventure but doable by anyone with adequate mechanical skills and a modicum of patience. The hard part isn't changing the belt, it's getting to it. The belt itself is cheap, I believe around $50 from JAE. The hose set is expensive and a couple of the hoses are the devil to get on, but worth replacing as long as you've removed the components to get to the timing belt. Otherwise, you'll just have to go through the process all over again when the hose lets go and leaves you stranded.

My Esprit sat for over four years, but seems to have survived the hibernation in reasonably good condition. You will probably have to replace the breather pipe between the two fuel tanks, it cracks and you get whiffs of gas vapor on occasion. Scary at first, and then just annoying.

There is a plug on the right side fuel tank to drain it. If you pull off the feed hose to drain the tanks like I did, it makes a real mess and sets up a serious fire hazard. Worth going with fresh fuel just to get that variable out of the equation.

If you need to replace the tires, I highly recommend Toyo T1R. You can get the correct sizes for the 90 SE in a 45 profile, and they stick like glue.

And don't worry about the immediate hiccups. My 90 SE was trouble free for three years until I shut it down due to an aging timing belt, and then it took me four years to get back to it. There are inevitably some teething troubles, but once resolved, it's a pretty solid car. Remarkably reliable for what it is, and most of the wearable parts are off the shelf from a large manufacturer, so they're relatively inexpensive.

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Well we can mark bad gas and clogged fuel filter off of the list... I changed the fuel filter, drained the gas tank, ran injector cleaner in it with new high octane fuel, and still doing it... I will tackle the plugs next, but wanted to get some advice on a few other things to go over on the checklist while waiting on the plugs to ship?.. And any recommended plugs to run on the 90SE?.. If I'm gonna change em, may as well do it right the first time

(Oh, timing belt is showing cracking, so I am looking SO forward to that one once i get it running right.)

I was thinking:

1. Fuel injectors and/or connections - Since I dont really get any increased smell of raw fuel when it starts consistently missing, I am still looking hard at a potential lack of fuel to the combustion chamber in one of the cylinders... And since this is a rhythmic miss through out all ranges with no fuel odor, by first thought is one of the injectors is failing.. It will idle fine when you first start it, and even up to 2000-2500 rpm, but as soon as you start rapping the engine upto 4000 & higher it just loses it, and then starts that missing through all ranges!!... Let it cool down & sit over night, and presto, you are back to square one, and the problem just repeats itself.

2. A bad ground somewhere? But I have no idea where all to check to be thorough..

Thanks

Chris

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Compression check, fundamentals even if only to cross it off the list.


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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The recommended plugs for a 1990 SE are NGK BPR6EKN. Make sure the gap (2 on each plug) is between 0.9 and 1.0 mm. check by means of a round feeler pin.

Freek


Esprit Freak

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If it runs fine up to 2500 rpm, but starts missing over 3k, that's about where the boost comes on.

Don't know if this will tell you much, but you can disable boost by removing the control arm from the wastegate actuator. This leaves the wastegate open (mine did this by accident). See if it misses at 4k with no boost at all. BTW - the Esprit is slug slow with no boost.

Also, you have four primary injectors, plus two secondary injectors, I believe under the plenum. If I'm not mistaken, the secondary injectors don't come in until real power is needed. One of them might be clogged.

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Well this post was started back in July, but I am on the home stretch of getting ready to try this again, and was wondering if there were any ideas out there for when we get the car back together.

- Water Pump has been rebuilt (Thank you again Jim Knowles!!!)

- New Timing belt tensioner is going on (mine was shot when i got it off the car last night)

- New JAE Gates Timing belt going on

- New (x3) Accessory belts going on

- New Fuel Filter is on the car

- New 91 Octane fuel is in the tank

- Injector cleaner is mixed in as well

So, when we get the pump & belts back on tonight I am going to fire the car up again... I am pretty sure its still going to misfire like it was since it was soing it before we tore out the pump & belts, so in theory nothing should be different as far as how its running.

Here is the break down on what is happening: The car starts fine. When it fires up it idles good, but about every 3-4 seconds you can hear a little mis as the car sits at idle speed. Nothing major, but its very regular. You can also smell fuel strong from the exhaust. When you slowly press the accelerator down. the car will start to miss fire more & wants to stall, but it does continue to rise in the RPM range, and as it gets moving it finally smoothes out a little more & runs smooth. BUT, when you give the gas pedal a hard stomp, the engine wants to stop firing completely & almost dies, but will catch on & start to smooth out again if I ease up the pedal a little bit to let it catch up.

Before I took the belts off, I installed new NGK plugs to see if that would take care of the stalling issue. But after only running the car for 4 or 5 minutes playing with the pedal, I took the plugs out, and they were black & smelled like raw fuel.

Anyone have any ideas we might check? I am running the recommended NGK plugs, and the gaps are 0.8-1.0 range. Thought maybe they needed gapped a little more, but I cant imagine that being the core problem. it was doing the same thing with the old plugs, so elimination tells me this isn

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I will take a look at that too... When I get the car running again I will get some more data...

If I adjust the fuel ration, wont the ECM fight me for the comensation making it hard to dial in?... I may have to bump this to the other forum depending on what we find.

thanks

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Chris,

Not sure what you mean by "adjust the fuel ration" but definitely check the fuel pressure to make sure the pump is functioning properly as well as the regulator as Sanj mentioned.

I assume you aren't getting any CEL?


1995 S4s

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I think Chris might have thought I was suggesting he adjust the fuel pressure regulator. Chris, they are not adjustable, but they do fail. Often this causes excess fuel at low RPMs, and insufficient fuel at high RPMs. If you pull off the vacuum hose going into the top of the regulator and fuel comes out, you have a problem.

Also, that hose is known to wear due to the chargecooler rubbing on it, so if it has a leak then the regulator doesn't regulate.


Visit Sanj's Lotus Esprit Turbo SE pages

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Hi Chris,

I would suggest that you look at the HT plug leads. If they are the carbon string originals (like mine) they go hi resistance and give these

type of problems [as the boost kicks in the spark voltage required for ignition goes up] bad idling i had too.

But be careful, I tried to use copper leads with cheap plug caps, they arced across to the cylinder head - not helpful at all!

The SE Delco ignition coil packs 'pack' rolleyes.gif a good punch!

measure with a ohm meter if you have one...

An 'in-line' strobe light or neon testor light is a good way to compare good to bad.

[Note the coil packs are double ended - so one end bad does effect the other so 1-4 & 2-3 are related]

(a so called wasted spark arrangement as used on motor bikes for years)

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