[speedyg20]

Purchased a P11 from a tow yard for 400 bucks. 94k miles. I got it home checked all fluids and replaced FF and put a couple of gal of gas in the tank. Car has not ran in 2 years. Put a new battery in it and crossed my fingers,,,,,,,,,,, It started right up and ran smooth. smelled like HELL. (Bad Gas) drove it around neighborhood. It drove out ok. Let it run for 30min or so.
Now I started it a couple hours later and it is misfiring? I hooked up OBDII and says random multiple misfire! ARRRG! Probably clogged injectors.
Does anyone have any suggestions what i could check?

 

[Ajaxx1989]

tune it up.

cap n rotor
plug wires
plugs
air filter
oil change

then go from there

 

[00 blk G20t]

most likely water is sitting on top of a spark plug. I ran into this problem the other day after pressure washing my engine bay. I just pulled the plug turned it over and put it back. fixed.

 

[speedyg20]

UPDATE Replaced Plugs,Wires,Cap,Rotor with NGK stuff and changed the oil. Still no change in misfire issue. HMMMM. Still confused, maybe fuel pressure?

 

[Dave_sr20]

I would say our first guess with the injectors

 

[00 blk G20t]

maybe also try unplug the distributor connectors and plug them back in.

 

[johnsmithson]

You could have rousted something up in the fuel tank. If it has been sitting for a couple years without running it is possible that moisture is present in the tank causing the misfire. Try pouring some fuel stabilizer (Stabil) in the tank and it may help. It seems weird that it initially ran OK then started to misfire. You replaced all the obvious ignition system stuff so far. Hope that helps. Let us know what the solution was.

 

[speedyg20]

I am going to pull the fuel pump tomorrow and replace the strainer. while Im there I will see how bad the tank looks, Yuck... Next step I will pull injectors and send them off to be ultrasonic cleaned and flow matched. I hate chasing Gremlins...

 

[johnsmithson]

I am going to pull the fuel pump tomorrow and replace the strainer. while Im there I will see how bad the tank looks, Yuck... Next step I will pull injectors and send them off to be ultrasonic cleaned and flow matched. I hate chasing Gremlins...

Chasing gremlins is never fun but it looks like you got a good deal on this ride. You will find the fault sooner or later. The 2.0 engines are nearly bulletproof. Hang in there!

 

[Jellybean]

Doesn't the code tell you which cylinder is misfiring? My old P10 does.

I guess if you have multiple misfires it doesn't specify. But you can test the injectors to see if they are bad. You can listen to them with a scope to hear the click, pull the wires to see which injector does not case the engine to struggle, and also measure the resistance to see if they are in spec before you go through all that. Also, since you have new spark plugs, you can test for fouling - again to check the injectors. That's a quick test.

Check the hoses too, per the FSM. I've had problems like these before and only once was it the fuel injector. It was always something like spark plugs and/or wires (split boot), rotor cap, disconnected senor wire. It takes a bit of time and patience, but save you $$ and running around. Been there... The FSM is usually pretty helpful with this sort of thing.

It sounds like a good deal though if you can make it work. Good luck.

 

[speedyg20]

The code it displays is P0300. I will use a scope and test the resistance b4 I pull them out. It was only 22 degrees today, so I will try again tomorrow. BRRRR!
These gremlins are gettin the best of me....ARRRG! Thanks for the pointers.

 

[p10det]

Does it only misfire random at idol?
How is it under load?
Check fuel trims and such. Their is a number of things that will cause this.

 

[p10det]

I assume you already inspected air leaks and such.

If you provide good descriptions I can.provide you with diagnostic support.I can usually find a problem t like this very fast.

 

[speedyg20]

It misses at idol and also under a load. I have checked for air leaks. no leaks... I have been reading FSM and have alot to check. when you say fuel trims? please explain to this rookie mechanic. I do appreciate all the help. This forum speaks highly of these cars. I am hoping that I got a pretty cool ride. I am an old school muscle car guy trying to find a fun cool import to experience.

 

[reyesjnj]

i know some people wont agree but i have had clogged fuel injectors to the point the car runs on three cylinders.One way you check is by unplugging one injector at a time if the car changes in RPMs the injector is ok but if it does nothing that injector is clogged.

 

[speedyg20]

Well, I pulled injector #2 connector while it was running and ran no different. Must be injector #2.... I am going to pull upper intake manifold and fuel rail and clean and replace dirty parts. I could use any pointers. Like things to do or not do?

 

[speedyg20]

Well.....i sent my injectors off and had them cleaned, flowmatched with new o rings. I installed them with all new gaskets, checked for vac leaks. went together great. Started it up and it still misses. I am going crazy. I have replaced all related elec componants too. I am stumped!!!! Could I have a dirty, bad MAF? can it be tested before I spend the $$$? What else could it be?

 

[speedyg20]

I replaced MAF with a known good one.....stilll misses....I narrowed it down to cylinder #3. I pulled SP wire and got spark from plug. checked voltage on injector connector, that was good.
I used a stethascope and all injectors went tic tic. When I unplug injector or plug wire from #3 cylinder I get no change in the way it runs. I am going to check compression tomarrow. I still need to check FPR and fuel pressure.

 

[reyesjnj]

good luck keep hunting

 

[speedyg20]

well,,,,,no compression on #3 cylinder. I mean zero compression. I tested several times. I even squirted some oil in cylinder and still nothin, zip, zilch!!! all other cylinders were in spec.
could I have a stuck valve? or a bad lifter? I will pull vc off and see if everything is movin like its suppose too. any suggestions?