Chevy & GMC Vans

yes then it goes off when it starts.

flatcat60 wrote:yes then it goes off when it starts.

Sounds like your O.K. But why didn't you use MAF cleaner? It is sold by auto parts stores.

i didn't know better,i will be more careful what i do from now on.

flatcat60 wrote:i didn't know better,i will be more careful what i do from now on.

It's still not to late to do it properly.

1Gary wrote:A carbonized EGR valve would give a ruff idle giving you the impression of a rich idle.You just remove the EGR valve and clean out the junks of carbon.Then from the help section of your local auto parts store buy and install a screen gasket.It is a common maintenance item.

You might want to re-read this post.

1Gary wrote:

1Gary wrote:A carbonized EGR valve would give a ruff idle giving you the impression of a rich idle.You just remove the EGR valve and clean out the junks of carbon.Then from the help section of your local auto parts store buy and install a screen gasket.It is a common maintenance item.

You might want to re-read this post.

What are you talking about Gary?

when i filled it up with gas today.the gas cap did not make that suction sound, that my wifes blazer makes when its low on gas.

Don't worry about the gas cap...that won't make it idle rough. Gary said to look at the EGR valve. It only takes a few minutes to pull it and clean the small chunks of carbon that are probably built up. If it is clean, it could be the fuel injection system's fuel pressure regulator leaking excess fuel.

Check the EGR valve first. It costs nothing to do but time. Do a search and you can find pics.

Do a fuel pressure test, it could be your IAC is blown, but you won't know until you do a fuel pressure test. So do a fuel pressure test.

i had the dealer check the codes,they say egr was bad or clogged. i took it off and the pinicle valve is not stuck open.so should i buy a new egr or can it still be cleaned ? when you shake it up and down it has a slight rattle to it.

I have used a dentist pick in the past to get out carbon.Not sure about the rattle.I would guess you have carbon stuck up there.

It may have come unstuck just with the process of removing it. It doesn't take much carbon to make the pintle stick. One little chunk will do it. Stick it back on there and give it a try. if it's no good, then get a new one.

Unless I have my sensor initials mixed up, there is no MAF (mass air flow sensor) on a 1994. There is, however, a MAP (manifold absolute pressure sensor), and it is a small black rectanglular part that bolts to the upper plenumn and has a couple of wires plugged into it, IIRC. If I'm wrong, sorry, but I'm fairly sure.

If this is a W motor, and I know from owning several and working on several more that the first thing you test when it runs rich is the fuel pressure. What you're looking for is whether the pressure holds or bleeds off rapidly when the engine is turned off. If the pressure bleeds off in less than a couple minutes (It should hold for hours), then the spider and/or regulator, and nut kit (lines) are most likely bad. That should always be the first thing you check on a W, since it can and will ruin your engine by diluting your oil with the extra gas that leaks into the lower intake if left unchecked.

rlsllc wrote:Unless I have my sensor initials mixed up, there is no MAF (mass air flow sensor) on a 1994. There is, however, a MAP (manifold absolute pressure sensor), and it is a small black rectanglular part that bolts to the upper plenumn and has a couple of wires plugged into it, IIRC. If I'm wrong, sorry, but I'm fairly sure.

If this is a W motor, and I know from owning several and working on several more that the first thing you test when it runs rich is the fuel pressure. What you're looking for is whether the pressure holds or bleeds off rapidly when the engine is turned off. If the pressure bleeds off in less than a couple minutes (It should hold for hours), then the spider and/or regulator, and nut kit (lines) are most likely bad. That should always be the first thing you check on a W, since it can and will ruin your engine by diluting your oil with the extra gas that leaks into the lower intake if left unchecked.

you are correct.i cleaned egr and installed with screened gasket.seems like it is not loading up,but i have not let it idle for too long until i get more gas in it.my mechanic wants to check it out this week, and do a fuel pressure test.i will keep posted on the problem.thanks for the help guys

I agree with Roy in that you do need to check out the fuel pressure.Glad to hear that it seems you made some progress in this repair. =D>