The hesitation/miss from HELL!!!!!

[douglas vincent]

Goldurnit!

Its back. And this time it doesnt even trigger a CEL. It just happens. And no cel.

I am going to replace the ignitor tommorrow with a spare, check all electrical connections between the battery and fuse box, and cross my fingers.

Christ, not a hiccup at the Dyno pull, and one day till Rallyxross. Crap.

[douglas vincent]

So this morning I drive around with no problems. Drive out and pick up a used diamond coil pack ($60) which I probably don't need, pull the ignitor off the junked wagon and install them.

I am holding off on installing the throttle body with TPS because that is a pain in the arse.

[douglas vincent]

"new" ignitor and coil didnt help.

Now on to try a replacement MAF

[douglas vincent]

New MAF = no improvement.



OK, this is a new thing I am not sure I included in some past posts.

If you disconnect the MAF, the car runs rich as hell, but runs with no miss/hesitation. when I replaced the old MAF with the "new" MAF, it made no difference, it stumbled withen 200 yards down the road.

Fuel pressure is not the issue, I now have a fuel pressure gauge and it stays steady and does not drop or dip during the problem.

So I still don't know if it is a spark problem or fuel problem. I really don't want to run rallyxross with the MAF dissconectted but I will if forced to.

Damn, I am getting a little pissed.

I am going to install the other throttle body with TPS tonight. Don't want to but don't have a choice.

Other things could be the knock sensor and the speed control thingy (is that what it is called?) located right below the IAC valve. I may replace both of those as well tonight. FUCK!!!!!!!!

[douglas vincent]

Installed the other throttle body and IAC.

Nope.

Worse than ever.

And it now does it with or without the MAF hooked up.

But new news.

It appears to be gear related. If you are driving along steady and it starts to miss/hesitate/die and just keep the throttle in the same position and either put the clutch in, or whack it out of gear, the car responds instantly!

Any ideas? I am going to miss the first rallycross because of this fucking problem.

[evolutionmovement]

Is it primarily a steady state problem? Have you checked the plugs for fouling? Could be a vacuum line somewhere.

Steve

[douglas vincent]

Not the plugs.

I just now took them out and check them and check the gap. All was fine. Took it back out and as bad as ever. I feel like crying.

I have checked and checked all the vacumn lines. Maybe I am missing something somewhere. I just don't know. God I am so tired. I really wanted to make the first rallycross.

I am willing to bet it is going to be something so simple in the end. I just have to find it.

The vacumn leak is such a good possibility but I just cant figure out where. I know what I need to to check some spots over right now but if that isnt it, I am just up another hour and more depressed. shit.


If it is a vacumn leak, like a line that cracks just enough under load, would this cause such serious hesitation? And would this vacumn leak be pre-throttle body, manifold, or somewhere else?

Thanks if you can help.

[douglas vincent]

I am still at it but done for the night.

So I tried yanking out all my vacumn lines that I use out of the intake manifold and plugging them up.

Nope.

But its load related. Rev the engine in neutral and wham, bam, thank you mam, we got power. Put it in gear and it starts to miss, stumble and die. ?????

[douglas vincent]

What does the IAC do?

I get code 24 which is abnormal IAC which = Prevents abnormal engine speed using "fuel cut" in relation to engine speed, vehicle speed, and throttle sensor position.

Would this explain it?

I replaced my IAC with a differenct IAC from a AT vehicle and it was slightly different.

[professor]

use a timing light to check each plug in turn. That will tell you if spark is dropping out or not.

What does your O2 sensor say when the miss occurs ? If lean its probably a fueling issue, if rich, a spark miss or timing issue

can you make it miss while sitting still against resistance from the brakes ?

have you re-checked compression lately ?

[douglas vincent]

CURED!!!!!! (but cross fingers, knock on wood, throw a cat over your left shoulder).

Dirty fuel pump sock.

Since this one had 230-240 thousand miles on it and fifteen years, I guess it was time for replacement.

I just imagine what my dyno run would have shown with proper fuel delivery.

[Kelly]

Damn dood. I was lookin for ya yesterday.

[douglas vincent]

Bad news or good news?

Good news first. Replacing the sock did wonders for idle and drivability and the fuel pressure jumped about 5 psi from replacing it alone.

Bad news. The "bog" is back. I drove it around about 15-20 miles today, even raced and beat an infiniti G-35 to 80, with no problems. Then tonight I say goodby to the wife and kids as they head off to the beach, hop in the wagon to get some gas and about 1/4 mile down the line, bang, the dreaded bog returns. Does it on and off for about 5 miles. Then goes away.

I am still suspecting fuel, but it could be spark, but if it is fuel, something is clogging the line somewhere that DOES NOT affect fuel pressure. So maybe somewhere an O-ring or something is getting sucked into the opening and blocking fuel flow, but the pressure remains the same. I can only sit and cry at this point. I have to drive to Bend Oregon tomorrow and was hoping for a fun drive. Probably not.

[biggreen96]

how are your plug wires doing? are they secure on the plugs? I had an awful bog in my 96 a while ago... one of the plug wire "sockets" was loosened from repeated taking on and off, when i was cruizing it was fine and if i gave it gas the wire would lose contact and bog.

[douglas vincent]

plug wires are new magnecors. I had new wires and had the problem, replaced them with the new magnecors and problem stayed.


I replaced the knock sensor tonight and purged the fuel system in the injectors. Problem remains.

[BAC5.2]

Sounds dumb, but have you reset your ECU?

You didn't mention doing it, so I'm just covering that base...

[douglas vincent]

I get confused about the "resetting" part.

I have multiple times hooked the black and green connectors up and driven around for the prescribed 1 minute or so, stopped turned off the motor, and the the CEL is gone.

I have yet to manage to actually 100% clear the ECU so when you hook up the black connectors no codes show. I just ran outside and unplugged the battery and will leave it till tommorrow where I will attempt to start the wagon and leave it running for 10 minutes without touching throttle. Will see if that works.


And what is really annoying (on top of being "just" annoying) is that this problem does not trigger a CEL.

[drive]

update?

[douglas vincent]

I think the problem at that point was a plug wire "sitting" on top of the #1 plug and not "clicked" on. It was extremely hard to get this plug wire on since the supercharger is right on top of this area.

Or I simply needed new plug wires. That has been the case two or three times now.

[scuzzy]

I think the problem at that point was a plug wire "sitting" on top of the #1 plug and not "clicked" on. It was extremely hard to get this plug wire on since the supercharger is right on top of this area.

Or I simply needed new plug wires. That has been the case two or three times now.

I'm saying it's a spark issue.

I had a Ford escort that had a plug wire from a different car, the rubber mate portion of the plug wire didn't allow the clip inside the boot to even get CLOSE to the plug, but I couldn't figure out what the deal was. it would miss every time under load because the spark was jumping right through the boot and to the block (easier to ground)

I finally figured it out, trimmed the bottom of the boot to fit, plug up. voila. problem solved.


Speaking of it. since the EJ22T swap, my car misses at idle.

It's not bad, doesn't try to stall, and it doesn't do it all the time, but randomly it'll just missfire and you can hear it, like *whump* putt-putt-putt-putt*whump*putt

no hesitation under load or while driving, just at idle.

weird stuff mang.

[douglas vincent]

Have you changed the plug wires? Seriously. I went though a set of plug wires in only six months. Actually, only one plug wire was bad, but man, it was frustrating as the miss would come and go, untill it just wouldn't come back and I had to run on 3 cylinders for about 20 miles.