HELP! Disco I CEL running rough sluggish

[JPC97DiscoSD]

In the past I have used Mobil 1 Synthetic 10W/30 and filter. I got the oil for free. I just used it as a temporary change because I am looking at the possibility that my old oil was fouled or contaminated. But I will check out my injectors. I am going to look up my codes right now, thank God for this cheap code reader I love it! I didn't realize I possibly have an injector issue.

So a bad injector might cause this?? So if the noid light beeps the injector is good or bad?

Just to clear things up:
Would a bad head gasket make the truck run terrible and cause bad compression on cyl 4?
Also, is it possible I might have a cyl. head problem, i.e. stuck valve or carbon buildup?

Thanks again guys, keep this post going if anyone else has some advise.

[Rovin4life]

if a noid lite lites and flashes as the injector is constantly opening and closing then the circuit is good. if it doesnt then the injector is bad.

no headgasket problem just the injector circuit.

[Adam in NYC USA]

Thats the test for the injector circuit working but what if you have a corroded injector? An injector with a jammed pintle will work just as well on the electrical side.

[mikekapo]

You might want to check the ECM for water entry. I had something similar these past couple of months and ended up replacing the ECM with one from Ebay. HTH

[VXRickXV]

Originally Posted by JPC97DiscoSD

Ok, I have the exact same situation it looks like.
After messing around for a while and not making any progress, I took my truck to the independent Euro mechanics so they can have a quick look over and give me their opinion, thank God they are around the corner from me minutes away and I was able to drive there. So I gave it a shot, the compression test cost me a few bucks even though I could have done it myself. In a sense I am glad I am getting to the bottom of this.

So the next day, I get a call and they ran a compression test which revealed low compression on Cyl. 4. So I have an internal problem now. The truck runs and drives, it is just really sluggish at around 2 - 3.5 rpms. This problem seems to have happened overnight and I am thinking the problem is in the heads, maybe stuck valves. I don't want to know what it looks like under there, maybe the previous owner ran 87 octane, and it was just a matter of time before the damage was done.

Is there any way I can clean the valves with an additive or something before I start digging deep into the engine and my pockets, should I change the oil and add some compression booster or some kind of engine treatment. I ran a can of seafoam thrrough the intake, should I do a can in the crankcase? Let me know what you guys think. I do have a crack on my exhaust manifold by cyl.4 - would that cause the problem, when it is running slugging it backfires through the intake and pops? It feels like I am running without a spark plug. Although it starts right up smoothly. Thanks for the input in advance.

I have cleared of my CEL and it hasn't returned.

I got a similar problem. mine is piston one. sticky valve, carbon buildup. this is what I did and it has inproved performance significantly: I've added lucas injector cleaner and always use 93 octane gasoline plus an octane booster on everyfill up. I mostly use shell gasoline because it has good detergents. I did notice a difference using just the premium gas. Then I started using the octane booster and an other significant improvement. It feels like the engine has really cleaned up considerably. my check engine light is still on but it never flashes anymore like it used to.

[VXRickXV]

Originally Posted by JPC97DiscoSD

also it seems the truck idles better with the MAF unplugged.

what's the "MAF"? an air sensor?

[sirchadd]

MAF is the Mass Air Flow, measures air coming in through the intake.

Definition:A mass airflow sensor is used to determine the mass of air entering an electronically fuel-injected engine. The air mass information is necessary for the engine control unit (ECU) to calculate and deliver the correct fuel mass to the engine. Air changes its density as it expands and contracts with temperature and pressure. In automotive applications, air density varies with the ambient temperature and altitude, and this is an ideal application for a mass sensor.

Yeah they are known for going out. But ECM problem can occur, especially if you are missing the rubber molding that runs along the fender sealing the hood to the top of the fender.

I have also seen the MAF wiring harness damaged. I suppose that is from people pulling the intake hose and forgetting about the sensor.

Most of the time when you see White smoke, you have water somewhere, from the head gaskets of in the fuel.

You can take a sample of fuel and let it sit to see if it seperates, thats an easy check.

Sir Chadd
Rover Tech.