Engine running very strange need help!

[esp88]

Hi folks

I need some help to solve my engine problem! :crybaby:

Yesterday started running very strange and the idleing was some time down to 900

and the Engine responding very strange.

Check with free scan and and tried to change idleing up but not work and even IAC showed high value ! I also reset EUC and IAC but it's not work.

I also got code 26 and 45 ?

Checked ing. plugs, all 4 plugs showed very black!

My guess is too rich fuel ! Read the manual code 26 and 45

.....

I'm thinking it may cause by one of injector is sticking open ?

e.g secondry injector ?

Does anyone had same problem ?

Y.Hotta

[CarlC]

Hi Yasuo,

Cant really help with this one, but having read your post I had a quick look at your profile and noticed that you appear to have upgraded your Esprit with S4 ECU and injection setup. If this is correct it may be worth mentioning in your post to save a bit of confusion when people try to reply with help.

just a thought... Good luck getting it sorted...

[esp88]

Yes, My esprit has S4 engine and the fuel injection !

it was last year swaped carb. to S4 inection and ECU !

it's running fine until last few days ! it looks like high rpm has no problem but

but between over 2000 - 4000 very strange some thing like not enough fuel or opssit. running just idleing in few minuts then slowly went down and can't keep 1000 rpm!

Does anyone know what happen if one of sencndry injector sticking open ?

Y.Hotta

[Artie]

Yes, My esprit has S4 engine and the fuel injection !

it was last year swaped carb. to S4 inection and ECU !

it's running fine until last few days ! it looks like high rpm has no problem but

but between over 2000 - 4000 very strange some thing like not enough fuel or opssit. running just idleing in few minuts then slowly went down and can't keep 1000 rpm!

Does anyone know what happen if one of sencndry injector sticking open ?

Y.Hotta

Unplug the secondary injectors and see if it runs normally. If the plugs are coming out black, are they wet? Or just black. Think there is something more going on as the secondary injectors won't be getting a firing command until at least certain throttle input over 50% and 3000rpm.

Artie

[esp88]

Thanks Artie

My guess is one of secondary injector open all the time, so get too much fuel under 3000 rpm, but running over 3-4000 rpm engin run better because enough fuel ?

Any comments

Y.Hotta

[t70]

if the engine is over-rich (which it clearly is due to your black plugs) your horsepower as revs increase will seem to as if the ignition is extremely retarded. I agree with unplugging your injectors, but i've actually never seen an injector stick open. I would think it more likely to be your tps or something along those lines. if the engine responds really poorly at light throttle and well at full throttle then tps may be your problem. The computer should go into "closed loop" operation at about 90% throttle or so. Once it does that, it stops paying attention to a lot of the engine sensors. It still monitors TPS and MAP sensors. Some programs still monitor engine temp. If your temperature sensor is pooched then the engine will run okay cold but terrible as it warms up. If you can add anymore, i may be able to assist... but i'm unsure.

[Dermot]

It does sound like a fuel problem. We are really groping in the dark without a Frescan log to confirm O2 sensor output is above .75 V. The BLM values will also be very informative.

For a code 45 there is a full diagnosic fault finding flow chart in the EMH.4 manual.

Dermot

[esp88]

Thanks guys

I check this morning secondary inejctors and it's not sticked open !

So, my first guess was Not correct !

I will connect free scan to check what infor I can get ! and inform her !

I have to take a public transport today , so I can do not much in winter weather (in Copenhagen was snowning this morning! ) and I have no garage !

lille more infor. while running idleing it showed free scan most of the value was showed as the free scan manual !

I will also check again all the cables/ground connection !

mean while thanks all guys I will update this weekend !

I hope I can solve this problem this weekend otherwise I have a problem to attend the Donnington !

Y.Hotta

Edited February 28, 2007 by esp88

[t70]

code 45: Oxygen sensor detecting rich situation

code 26: secondary injector driver

I'll spend some time later reading the trouble code diagnostics... but I would check the wiring and grounds to the secondary injector driver...

[esp88]

Just back from work and I logged just lille csv log yesterday ! :yes

Does any one can look at the see what can be wrong !

I attached log file her. I logged while engine was running as idle (not driving)

ups I can't upload exec file ?

Y.Hotta

Edited February 28, 2007 by esp88

[t70]

You've got 2 values that are all over the map... one is your 02 sensor voltage... it's up and down all the time, and it almost (but not quite) corresponds with the other value that's all over the place --- your spark voltage. I think you've got a bad ground honestly. I would look into your coil wiring. The coil wire is generally the same line that goes to the ecu. In-fact, in order to bypass a factory alarm system... that's generally what you do -- hook up the positive and negative from the battery directly to the coil... So, since your coil voltages are all over the map, I'm guessing that's what's causing your problem. I would like to see another map though, with you revving the engine, bring it up slowly to 4000rpm and record that.... I may be able to tell more.

[esp88]

Thanks Mark-TC

I also noticed the O2 voltage was up/down and the knock sensor vaule may wrong ?

I will check O2 sensor, the Coil connection and keep inform her tomorrow (I will take fri from work)

Great to hear others advice !

Regards

Y.Hotta

[t70]

I think it's most likely that your coil itself is pooched. I didn't notice any knock voltage at all.. which either means your knock sensor isn't working or that the computer only registers it above a certain point. I suspect the latter is true. You should have at least one, if not 2 knock maps. So... you've got your main base map and then a slightly richer and more retarded ignition for the knock map. Knock sensors are also only monitored in open loop mode. So, once you exceed 3000 or 4000 rpm (yours is a gm knock sensor and i think that that is only monitored to around 3000rpm) the knock sensor is no longer used in the computers ignition and fuel considerations.

On the note of the coil -- if you look at your coil voltages, they are anywhere from 0.2 to 8.8v.... So I think that's why you're showing rich. Your spark voltage is too low and not burning all of the fuel causing your 02 sensor to pick up a rich situation and then your injectors dump less fuel and your rpms come up and then your computer says that isn't right and drops your idle... it's a big old circle... but i'm pretty sure your coil is the problem.

[t70]

I just realized your in Denmark... I'm gonna be there in may for my baby sisters confirmation! We should hook up then!! I'll be in Copenhagen for about a week around about the 10th of May.

[esp88]

Hi Mark-TC

Many thanks the infromation I will check the coil !!

If you comming to Denmark(Copenhargen) just call (+45) 29236650

Y.Hotta

[esp88]

Still running very bad but after checking cable connection etc..

I only got code 44 !!

And her is the new freescan log !

Does anyone check the log ?

Y.Hotta

[t70]

Your coil voltages are even worse this time... were you "blipping" the throttle to keep it running? I ask this because sometimes your idle is all the way up at 2300rpm... oh wait.. just looked at the map again... you were blipping the throttle... so, I'm still confused as to why your coil voltage is all over the place... There are parts of your map when the coil voltage even hits 0. I'm still convinced it's your coil.

[esp88]

Sorry Mark

I have a spare coil, so I replaced but nothing changed !

(and 12 V to connector )

I think I tried to RMP up lille up to see it's changed !

Now I have ony code 44 (O2 circuit problem) and checked manual !

Manual mension some points like fuel pressure, MAP sensor, ..

I tried to disconnect O2 sensor !

What happen is running much better and Not black exahus but when I reconnected O2 sensor started again !

Questio is ECU or O2 sensor ?

Any comment ?

Y.Hotta

Edited March 3, 2007 by esp88

[t70]

When you disconnect the 02 sensor it goes back to basics... it goes to it's "Base map" and is effectively in closed loop operation. So, almost certainly your o2 sensor. I say this because your 02 sensor readings are fairly consistant throughout the entire map. So, maybe there's a part of the program in the computer that changes spark voltage as well as fuel mixture according to the o2 sensor. Normally that's done by load and tps but who knows. Your engine should normally run just fine without the o2 sensor, you just won't pass emmissions. So, I would say that you should disconnect it, take it for a good drive and see how it is. Since you said your spewing black smoke and according to your ecu datalog you are pretty much at a 14.7 AFR most of the time, then I would say that your 02 sensor is definitely reading incorrectly. You shouldn't see black smoke untill about a 13 AFR or lower.

oh yeah.. I probably wouldn't go full throttle on your test drive... just to be sure. And keep your ears open for any detonation (should sound like coins rattling around in a glass)

Edited March 3, 2007 by Mark T-C

[esp88]

Thanks Mark

Such a quick reply !

I checked again logs and As you see in log O2 sensor showed very low voltage but

came black gas out after few min.

I took some logs with and without O2 sensor and tried to understand what showed.

When I disconnected O2 sensor the stop black gas no misfiring !

and ideling is OK. the last logvoltage showed very low. when I disconnected showed constant around 0,475 V.

So, I hope the problem is only O2 sensor (hope Not ECU).

I wil test drive tomorrow without O2 sensor !!

Regards

Y.Hotta

Edited March 3, 2007 by esp88

[Dermot]

I am afraid I need to correct Otis on a few things before you make things worse.

When you disconnect the 02 sensor it goes back to basics... it goes to it's "Base map" and is effectively in closed loop operation.

This is incorrect, the ECU supplies 0.45 volts between terminals J1A16 and J3C19 (ie. O2 sensor). If there is no sensor the ECU see a fixed value and will stay in open loop as their is no adaptive feedback from the O2 sensor. The engine will run very rich as a result.

Normally that's done by load and tps but who knows. Your engine should normally run just fine without the o2 sensor, you just won't pass emmissions. So, I would say that you should disconnect it, take it for a good drive and see how it is.

Wrong, the car will not run well without the O2 sensor, it will overfuel, stumble, stall on warms starts and you will kill your CAT or potentially have a fire if the CAT gets too hot as a result of the exothermic combustion of that unburned fuel. O2 sensor is a one of the most important sensors in the car.

Since you said your spewing black smoke and according to your ecu datalog you are pretty much at a 14.7 AFR most of the time.

The AFR ratio recorded in the Freescan log is not the actual realtime AFR it is what the ECU is trying to achieve via the O2 sensor. You can actually seen from the very high BLM value in the idel cell that the fueling is all wrong.

Right, having looked at your log file you have a bust O2 sensor. You also have an issue with the MAP sensor. The readings are irratic and not helping things. I think you have a perished hose somewhere on the MAP sensor line or elsewhere in the manifold and/or a possible map sensor on the way out.

Dermot

[t70]

I apoligize for my incorrectness... However, during the tuning of my 300zx, i only used my wideband to tune with, and wether or not the 02 was connected hardly mattered. It is dependant on how rich the base map actually is, as i recall. I agree with the possible engine damage with regards to the cat, but man... you'd have to be running very hard for very long to catch fire to your cat. With regards to the map sensor -- I think that was just him blipping the throttle wasn't it? again... i've been wrong before.

[esp88]

Thanks folks

I think I'm learing a lot !

My car has no CAT, so no problem that point !

I have also a spare MAP sensor, So I will replace MAP and check the vaccue line to MAP sensor !

I have no spare O2 sensor at the moment, So I can't see O2 sensor is deffected !!

Any id

[Dermot]

Otis,

No problem we are all still learning...

In the log the initial idle MAP value is a little high and the IAC is low. That's why I suspect a problem there.

The stock Lotus fuel and VE tables produce a rich initial setup.

I heard that there were some issues with CATs overheating when the O2 sensor failed on the Elise. They now have thermal insulation in that area.

D.

[t70]

interesting about the elise.. but isn't that a toyota motor? I wouldn't expect the esprit to have anywhere near the same kind of issues other than the cat being very clost to the turbo exhaust. I had missed the initial map readings... i was really looking later in the map where they were all 0 untill he hit the throttle and it went up to 2 for a second and 10 load. I guess the base map is very rich for engine protection... if anything went wrong then engine detonation would surely be a very scary proposition. However, I personally go by the route of tune the base map perfectly, and you shouldn't have to worry about the rest of it... Though... I also don't have a cat in the 300zx, and egt's arent very high with a t70 turbo and a straight 3" exhaust!! hehee..