Hello and thank you for any input you can offer!

I have a miss in the engine but not consistent, it will die if I don't give it throttle in drive when I come to a stop. In park or neutral it just hesitates but doesn't die. It does miss at highway speeds but can barely detect.

I did a vacuum test and found the module just before the EGR Valve held no vacuum with engine off. As well, the device before that right under the intake manifold, fuel pressure regulator? also doesn't hold vacuum. Am not sure if this means that these two items are faulty?

Thanks for any help you can give!

 

Same miss, engine hot or cold?

Any hard starting?

Have you checked ign system including coil.

Can you post photo of module? Is this shaped like a can?

 

Same miss cold or hot.
No hard start ever unless I let it die and then it might take one more crank than normal.

List of items replaced in the last 6 months or so:
Coil, cap, rotor, wires, plugs & PCV valve.
Thermostat, timing belt, fuel filter.

Before replacing the coil it had a similar miss but went away after install.

As far as the fuel reg, it is under I take on the passenger side and has two ports with electrical terminal.

Hope this helps narrow it down.
Thanks Joey!

 

EGR valve vents to atmosphere when off, should be off at idle. If VSV is stuck open and EGR is on at idle, this can kill engine.

The fuel pressure regulator looks like a can bolted to the fuel rail and having a vacuum hose attached. Not electrically powered.

The IAC valve controls engine idle. Perhaps it needs cleaning (common) or has failed. The internet has info, perhaps even video on how to clean the valve. Suggest cleaning valve as this may solve the dying at idle issue.

Use a throttle body cleaner safe for plastics, any auto store will stock this. With engine running, spray cleaner into the rectangle slot in bottom of throttle body and located before throttle plate. Engine will want to quite, thus apply more throttle. Also clean throttle body and plate of grime, use a tooth brush then wipe away grime with paper towel.

 

Thank you Joey, will give this go!
IAC valve is the one that had no vacuum retention.

 

Post back with results of cleaning.

The air port on the bottom of IAC valve may vent to the throttle bore and as such not hold a vacuum.

 

Well, I changed out the EGR and the Vacuum modulator, also cleaned the TBI as well. It has a higher idle till it get all warmed up, BUT, it still has a miss! Not as bad as before when it would die at a light but is still there!

So what does anyone say to that?

I am at my wits end!!!

 

Higher idle at warm up is normal.

Make sure VSV for EGR is off.

How is engine performance above idle, as in any miss when driving?

Do you still have the old spark plugs. If so, compare all 4 for 1 that may be different as in darker, blacker, more soot, etc.

 

The higher idle was not there before the EGR replacement. Was of course before issue started thou.

How is VSV tested for being off?

Spark plugs were all consistent and grey/white.

Engine performance is excellent with a minor miss barely detectable on hills.
Is so much better thou with the EGR replaced but still there just not as bad.

 

Well, bad news, now it has died and won't start. Doesn't sound like timing belt (since that is new). I think it's the coil which I just replaced three months ago!