poor acceleration, doggy, etc...

[Jgrauman]

great reference picture.
That looks good, and i thought my truck was fairly unrusty.... Is that the magnaflow y pipe?

Yes MagnaFlow y pipe. That stinking exhaust is the only rust on my truck. Think I'm going to sand blast all the pipe. It's mostly caked on dirt

 

[MrSmokey]

Exhaust parts came in...

 

[MrSmokey]

Just pull thr exhaust out of the way after the y-pipe. Before the cats. See if it drives better(its going to be stupid loud). I had cats fail on me, exhaust smelled different and the exhaust manifold to just behind the cat got hot in a hurry. Try to compare with a known good running local 80.

I removed the exhaust, right before the cats. I do not think the o2 can sample enough, it hardly wants to move like that. My cats did not look bad, still, they could be plugged, but they are not trashed, i probably could of cleaned them, or this is another issue.

I'll pull off the PAIR and mount them up there and try it once things cool down.

This wont get done today, i hoped i could re-use my exhaust hangers, the rubber is good, but the studs snapped off all of them.

 

[Jgunner]

Hardly moves with no exhaust? It should run decent, not 100% but just throw a code. Something else is prob a mis.

 

[Jgunner]

Have you checked for vacuum leaks?

 

[MrSmokey]

Have you checked for vacuum leaks?

I just did all hoses, and the manifold gasket. but the huge lack of power happened after the igniter and coil failure, it ran ok before then.
new hoses, gaskets, etc have not changed performance, but made it run a lot smother and fixed the surging and hesitation that showed up after i got it running again, after the igniter failure..

I sprayed starting fluid around the intake, no change in idle.

I dono, the o2s are about an inch from the cuts, and it would have no backpressure and stock tune, it should run like crap i would think.

i remember as a kid when i ran my 56 chevy with open headers without dealing with the carb or ignition, ran like garbage, no power, and it did not have a confused o2.

I did put a NOS FPR on, maybe that is no good. Or, could the fuel relay get stuck at low flow? I'll confirm that the relay is working tomorrow.

eitherway, the exhaust needs to get done, so i'll do all that.

 

[Jgunner]

Ive run open headers on stock stuff before, it makes them sluggish by maybe 20% or less, but i would stick a fuel pressure gauge on it(mechanical) also forgot if youve checked the plugs lately and tested plug wires?

 

[MrSmokey]

Ive run open headers on stock stuff before, it makes them sluggish by maybe 20% or less, but i would stick a fuel pressure gauge on it(mechanical) also forgot if youve checked the plugs lately and tested plug wires?

New NGK nickel 0.8mm gap, new denso plugs, cleaned and flow matched injectors, when i did the intake etc.
I should get a gauge, i have needed one for a while.

When i got it back together after the new coil and igniter death ( and me flooding the heck out of it while sorting that), it ran as normal for about 20 miles of city driving before it started being doggy, surging and hesitating. The next time i took it into town it started out ok and once it got hot it would start doing it again. It then was only doggy, surging etc during driving. Idle was crappier.

I then did the plugs, wires, injector, fpr cleaned intake and tb, new gaskets on the intake and tb. It acted the same in the power department, but idles was smooth, running was smooth etc.

It is strange how smooth running it was when going up a hill, it just felt loaded, or like i was not pushing it past part throttle, not like it was missing. "stuck in econo mode" is the best example i can come up with.

I probably need to get the exhaust back together before i start screwing with anything else.

i have never run open headers with the 02 so close, but was pretty surprised it did not want to move much at all, it would not have made it in up the driveway.

WOT would kill it, not enough fuel at wot?

What happens if the fuel pressure VSV goes bunk? Does it just hold it like it has full vacuum? I have never owned anything with vsv's before.
Maybe i should throw the old FPR back on.

fuel pump was replaced right before i got it, filter looks new, so i figured they did that too, i'll look at recipts.

Thanks!

 

[Jgrauman]

Would also investigate the vaf. I broke the no no screws open in mine and had to resolder Every time the solder brakes your symptoms arise.

 

[MrSmokey]

Would also investigate the vaf. I broke the no no screws open in mine and had to resolder Every time the solder brakes your symptoms arise.

I'll retrace some of the stuff i did, and get the exhaust backtogether, and then go there if i am still have issues.
Thanks for the suggestion.
Do you have any pics of the inside of the vaf/maf, or which solder joints(not sure how obvious it will be), i have never had one apart.
Not sure why that would go now though, i was careful when i pulled the intake etc...
I'll look in the fsm on how to check it.

 

[MrSmokey]

Would also investigate the vaf. I broke the no no screws open in mine and had to resolder Every time the solder brakes your symptoms arise.

i did find this pic, looks like the top needs to be yanked to get to the solder joints
Anyone selling MAF?

I am not messing with the vaf yet though, not till i rule out the stuff i messed with.

 

[Jgrauman]

That's it, yes you have to pull the top, just cut around the sealant and pry up. If you have never pulled the no no screws and are sure no po has then leave it be for now. Not sure if the solder joints are know to break from the factory but mine have broken 3 times from my solder jobs.

 

[MrSmokey]

That's it, yes you have to pull the top, just cut around the sealant and pry up. If you have never pulled the no no screws and are sure no po has then leave it be for now. Not sure if the solder joints are know to break from the factory but mine have broken 3 times from my solder jobs.

Thanks, there is decent clear sealant in there now, i do not know if it has been apart or not, but i suspect not.
got hung up on the pair studs today, and waiting on other parts. ...once the exhaust is on, i'll retrace stuff i have mucked with, try bypassing the fpr vsv, try my old fpr, etc... it is funny, i was thinking again about how to describe the characteristics, and the best thing i can come up with is it feels like i have a block of wood under the throttle pedal, and i cannot get even half throttle. I then went and rechecked my cables, and they are fine, and i did not somehow put them back on wrong.