V8 Stuttering

[KiteDiva]

Hiya!!
My new Van stutters. No...not when it talks to me but when I'm running at a constant speed or throttle setting. We've checked the rotor, cap, wires, spray pattern of the injectors, all the obvious culprits but it still stutters. It won't do it at idle nor does it do it under acceleration only when I'm cruisin' at a constant speed. The problem is more noticeable at slower speeds. Anyone have any idea why it does this and how do I cure it? Thanks so much!

da noob
Diva

[Kidhauler]

Sanj and I were talking and I think it could be your MAF sensor. If it isn't reading the intake air volume correctly that could cause a stutter. Either that or it could be your fuel pressure inlet spring in your fuel injection. We will get it sorted out for you.

[reaper]

We will get it sorted out for you.

Kevin will get it sorted out for you,
I'll be busy installing airbags into his van

[6spd_monte]

Sanj and I were talking and I think it could be your MAF sensor.

I could be way off on this, but I'm pretty sure the '89 doesn't have a MAF sensor. Do you mean MAP sensor? Although it reads air pressure, not volume.

Unless the V8 uses a later style of engine management?

[Kidhauler]

nope your right. I used the wrong term. One day I will learn to not post while having a beer.

[KiteDiva]

So would it help if I contacted the former owner (who installed the motor) and asked him what vintage the engine was? It may well have one of those MAF's or MAPs or whatever...(gods I wish you guys would speak english!)

Diva

[KiteDiva]

Well we have an update! It's a 91 or maybe 92 vintage engine from a pickup... Chevy of course! Oh and it does have a MAP sensor. Here's where it gets weird, the previous owner thinks it might be either the TPS or the EGR... and I'm now totally bewildered! On the bright side, I'll know more about 350 Chev motors when this is all done than I ever thought I would want!

cheers!
Diva

[kings-x59]

My two cents goes to the EGR valve, the vacuum controlled egr valves are hardly what I would call a precision component.
Mine sticks sometimes just because.... usually slowing down and then accelerating to vary the vacuum on the EGR hose gets it unstuck. I think yours is probably gummed up with carbon.

The vacuum EGR valves are notorious for sticking due to carbon chunks jamming the pintle.
And, it will make the engine stutter when it sticks. At idle it should be closed, if it's stuck open, it will definitely cause a rough idle.
So, one of three things could be wrong. Pintle is stuck due to carbon, vacuum hose from EGR solenoid to EGR valve has a serious leak, or EGR solenoid gave up the ghost.

[Kidhauler]

I have a EGR valve that will fit your engine you can have it for free as it will not fit my van. If I dig around I might even have a TPS sensor. I should be home Sunday if all goes well. I will give you a call then.