Jinxed myself - misfires 150 miles after HEI mod

[SuperK]

Replacing o-rings on the car is a pain. There are little plastic grommets that like to fall in the engine and are a PAIN to pick up if they fall.

I would suggest getting one of those little flexy arm picker upper things before working, because you can pick up the little grommet that falls when it does...

You can remove the fuel rail by just removing the air intake tubing .

Also, use a type of impact wrench to remove the little screws. You'll undoubtedly strip a few out if you don't.

take the injectors out, replace the o rings, lube them up before re-seating them.

I replaced my injectors in an hour and a half... but it was my third time doing so and I knew exactly what to do. It's a pain in the butt, but shouldn't take more than a couple hours with everything set straight.


Also, try this:

Remove the MAF completely. Out of the engine bay. Crank the car. It should just rev freely. Just remember to TURN THE CAR OFF to make it stop revving. If it rev's smoothly... well, you might just have to replace the MAF.

[Mazda_Powered]

damn, if it wasn't snowing like a b---- right now. I'd go check that MAF situation. I wouldn't wanna break anything due to the temperature lol.

[neumann]

This is the EXACT SAME THING that is happening to my 93 626 V6.

Does your car run then die the first couple of times you start it up too? (cold start?) because mine does, always dies unil the 3rd try where it always stays running.

My car misfires real bad if heavy load is added once the car is at idle too, sounds nasty. I've replaced basically the same as you, asides the HEI modification. Plugs/cap/rotor/wires.

I thought it might be the coolant temp sensor, because i've had them go back before and the car runs like crap. No change there either. I'm contemplating on cleaning out the EGR valve to see if there's any differences...but decided not to once i pulled the vac line off it and no change was had to idle/throttle.

Are you getting any check engine lights either???? I'm getting stupid angry with this car.

p.s. my car runs fine when driving around with low throttle, i'd say around 15-20% throttle. She runs off all 6 cylinders. Also when I park/neutral rev the car, it doesn't misfire past 1,500rpm lol.

JACK.

Jack

Sorry for the delay. I tend to only get a chance to look at my car on weekends. Kind of a pain because i go through the cycle:
Try some troubleshooting on the weekend
Experience problems
Post some questions
Read responses during the week
Try again next weekend.

Because of this and the fact that I will sometimes order parts online and then wait for delivery this can take a while.

I have not had Check Engine Light except for the very first time I drove the car after the HEI and external coil mod. It drove fine for 4 days and 125 miles or so. Then it started to behave much as you describe for about 3 days and 25 miles. The symptoms you describe were largely what I had (at idle with load at startup, no issues for me until about 2500 RPMS under load etc) but then it got worse. It now misfires under all circumstances and I am getting white smoke. No obvious coolant mixing with the oil. I went to do a compression test and after warming the engine then found that the depth and narrowness of the spark plug holes prevented me from getting my compression tester plug adaptor thing screwed in.

I have had misfires in the past attributed to air leak in the intake hose and a bad crank position sensor. I replaced both of those. This is much worse and more difficult to identify.

[Mazda_Powered]

well what i'd do if i were you is measure the resistance for both primary and secondary coil. By the looks of it you still have the tower for the secondary coil, so it might be interefering with your HEI modification.

I'm measuring resistance tomorrow for the primary (my multimeter doesn't measure below 10ohms ) I'll let you know what I find.

I'm pretty sure its the internal coil not being able to keep up with the cars thirst for spark.

JACK.

[Mazda_Powered]

Sorry, still haven't had much time to look into the car, I left my multimeter at my friends in my school bag (SOB!). So hopefully I'll be able to test it monday if I find time between an exam and work in the evening. I need to get this thing going!

Any luck yet on your end?

JACK.

[SuperK]

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That's me and my problem... I have a ZE, so it's more pronounced I would guess... but yeah.