Marc3.4V6

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The car used to start right up, but then I ran it out of gas and changed the pump and opti at the same time, it started good for a while but then once and a while would take a few cranks, or a really long one to start, now it's happening more frequently and plus it runs really rough for the first few minutes and goes away. It acts/sounds like an untuned cam. It didn't start to do this until I changed the fuel filter, but I think that's a coincidence. I checked the pressure and it is good 40-41 and it does not drop off when the car is turned off, holds pressure for a good long while.

Also, I've been getting an intermittent SES light once and a while when on the freeway for "EGR failure". I suspect that could possibly cause rough running, but the starting?

96LT1355Z28

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Why the opti and fuel pump change? Running out of gas isn't good on the pump but 1 time shouldn't require a new one + an opti! There's a good chance the emissions system is part of the problem but I'm not gonna be much help in that department!

Marc3.4V6

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It was the pump that time, I didn't install it correctly so it only gave me good pressure the first time, then slowly fell off the pump apparatus. I then moved on to the opti, which was a parts store one that I wanted changed anyhow. I figured it out, and fixed the pump.

I put an MSD coil on at the same time, I'm going to try going back to stock to see what that does as well as clean my egr.

Speedy

Stuck EGR valve for sure. Push your finger on the diaphragm a few times to see how the car reacts. It should be either cleaned or replaced.

Marc3.4V6

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hard to find the time lately, I once tried what you suggested briefly (engine was hot still so I gave up), but could not find the diaphram I hear about....where is it on the egr?



It seems pretty tight back there, is it hard to get off?

Marc3.4V6

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I can't seem to get it off, how did you guys do it? I can't see **** and can't even figure out what wrench to use on the retaining bolts.

Also, I accidentally took the vacuum off the fpr and fuel came out, doesn't that mean it's bad? It was all dirty too, black even.

Speedy

I used a ratcheting wrench with a flex head on the right bolt (as you face the front of the car) and a ratcheting shortie wrench for the PITA one on the left side. I won't lie, it was hell. You can clean the old EGR with solvent, or you can replace it if you want.

Anthony0908

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Y amine did that it stuttered in low rpm and had rough idle.
It was my egr .
Test it push the diaphragm in and hold your finger on the egr nipple were the vacuum hose goes. It should hold pressure.
But im sure its your egr replace it ths is typical with a chevy motor in general.
Also check for broke or cracked vacuum hoses

96LT1355Z28

iTrader: (2)

If you have fuel comming from the vaccum line of your FPR it's bad, change it. You may also have an EGR issue but deffinatly change the FPR!

Anthony0908

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O ya i missed that thats a must, its just filling up in your intake I had a dodge do that once.

Marc3.4V6

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I hope that is what is causing my hard starting, it would make sense that I am getting good fuel pressure and my spark should be good, but its not starting because it's flooded...

Anthony0908

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Thats positively it if fuel comes out it.

Marc3.4V6

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when I move this hose to the brake cylinder out of my way, like bend it in the middle:



It makes a hiss, making me think its cracked somewhere under the heat wrapping....I guess I need a new one but I can't figure out what it's called and can't find it.

(note - the green arrow is hard to see).

Marc3.4V6

iTrader: (1)

ok, so I've only had it back together for 1 day, but the starting issue is fixed so far, and the SES light hasn't come back on for the EGR, but the rough running has not and now I get white smoke at startup that lasts maybe 30 seconds, even in hot weather. I have never overheated, in fact the car runs very cool (new motor). Although my temp gauge has been malfunctioning lately. Also, it used to misfire in certain spots once in a blue moon, now it seems like it wants to misfire more, did it alot today right before accelerating.

So I've just replaced EGR, fuel pressure gauge, in case you missed it, both AC Delco....any ideas on my problems? A co-worker told me to check my compression, but I'm not sure if I have the patience to do it on the passenger side, unless there is another way of doing it I am not aware of.

x Wild Bill x

I know this is an old thread, but I just wanted to let you know that the hose is the vacuum line that goes from the brake booster to the intake. Just take it off and go into the autoparts store and they will match it up to a piece of hose for cheap. If there is a crack/leak in that hose, it would cause your hard start and miss, I think my car has the same thing, I have to check it out. Next, for your temp. gauge, it is hard to see, but it looks like the pigtail is not plugged in all the way into the sensor. It is right under your header on the drivers side head. This would cause the gauge on your dash to not work properly.

Did you get the problem fixed?
Good luck,
Bill