Loosing Cylinders Under Load

[Phantom409]

All right, I have had quite a day and did the one thing I tell peeps not to do and threw money at what I thought the problem was with no results

My car is loosing cylinders under load.
I replaced the Water pump because it was leaking as well as the whole Opti hopping that my issue would be fixed so I could dyno my car tomorrow with no luck.

I even unhooked my MSD 6 AL to make sure that wasn't the problem and I put on a new coil that I had in my garage with no change.

I haven't had a chance to hook my fuel pressure gauge up to it yet but I'm leaning towards a bad fuel pump??

Any ideas or am I on the right track??

[sman]

Done everything I would have done, not much else for there to be. You have a long enough mechanical gauge so you can run it into the car and check while driving?

[Phantom409]

Yes I do.
Just didn't have time to do it today.

[Will]

Did you get the Opti wet?

[Phantom409]

Not the new one!!

That's the thing, there was NO change.
Car acted the same way with all the new parts.

It idled rough at 1st then it just acted fine so I thought, SCORE but it was not to be
As soon as I got it out on the road and went to accelerate she started missing and dropping cylinders
I'll have to do a fuel pressure test sometime this week.

[1BADAIR]

how much load?
Common for plug wires to drop under load. sometimes causing a backfire too.

[WMCCjames]

X2.....sounds like a plug or wire. If you were losing fuel volume, the car would just lay down and be low on power....when you get a distinct drop on a cylinder it's most likely spark related...unless an injector coil is going bad.

Oh and shame on your Kyle for throwing parts at a problem.....

[JoeliusZ28]

thats what my car did for 2 years through 2 sets of plug wires.

you got OTVC?

[Phantom409]

thats what my car did for 2 years through 2 sets of plug wires.

you got OTVC?

Yes I do.

Coil was replaced.

I loose pwr unless it's WOT then she runs like her pants are on fire

[JoeliusZ28]

let me clarify:

heavy load, low RPMs = stumbling, missing

WOT, high RPMs = kicking ass and taking names

is that what its doing?

like this?

http://www.youtube.com/watch?v=aVFak...e=channel_page

[98blackbeauty]

Besides fuel pump and plug wires, the only other thing that comes to mind is battry or altenator, Low voltage will cause weak spark. Battry could have cell shorting out, voltage regulator in alt. could be crappin out. These would be on the wild side though.

[Ace2717]

Well if the car kicks ass when WOT in high RPMs, then the fuel pump is out because you would notice worse performance at higher RPMs.

I would also assume that if the car missed in low RPMs because of bad plug wires, it would continue to do so in higher RPMs.


My guess would be a timing problem, maybe its stuck in an advanced timing position.

[1BADAIR]

hmmm, 02's aren't used at WOT
clean the maf

[Rome]

So while youre missing and dropping cylinders at low rpm. but mine is dropping at higher rpm. mainly after 4g with a cold engine(sometimes it doesnt miss at all),and anywhere from 2g-3g on a warm engine. all ive had time to do so far is to change the filter, and check the lines from the tank to the filter. those are all clear. and i checked the resistance on my resistors, my 6&7 injector are an ohm low. any thought on what would cause the reverse of the above mentioned problem? btw not trying to jack your post just trying to find answers

[Phantom409]

Ya Joel, very similar to that but my car don't shake.