A fuel Problem.... 1990 IROC

[MurphyIsmyName]

I have a 1990 Iroc in it with a 305. It tries to start and tries to start... but never actually starts. I cracked the fuel line just before it goes under the intake, and it has plenty of pressure. I press the shrater valve and nothing comes out. It has a new fuel pump from what I am told.. new ignition module, tried different pump relays, new computer, and some other stuff. Just a run down of new or told was new parts...

I bought the car pretty cheap, and I think its the Fuel pressure regulator that is bad. Having no pressure at the shrater valve and plenty of pressure just before the intake is giving me this idea. ANyone know of any thing else that could be causing this?

How hard is the Regulator to change? ANy help would be appreciated... Thanks

[Morley]

Originally Posted by MurphyIsmyName

I think its the Fuel pressure regulator that is bad. Having no pressure at the shrater valve and plenty of pressure just before the intake is giving me this idea. How hard is the Regulator to change? ANy help would be appreciated... Thanks

That pretty much narrows it down. The regulator is a snap to change and costs about $25 at an auto parts store.
First, relieve the fuel system pressure. Remove the gas cap. Remove the plenum. Now you'll need a set of safety torx bits. They look like normal torx bits but have a hole in the end and the screw itself has a normal torx head with a small post sticking up in the center. (get the bits at any parts store) Remove the screws holding the regulator cap, remove the regulator and make sure none of the parts broke off and stayed in the hole it sits in. Install the new regulator making sure you install the reenforcing ring on the outside just like the old one. New gaskets for the plenum, close gas cap and turn the key on to prime the system (do it a couple of times). Check the schrader for pressure present at it. If there still isn't pressure then you have internal blockage in the pressure line on the manifold somewhere.

[97cavalier]

If i were you and if you are going to do mods, i would get a adjustable one, wortht he money!!

[tom bezaire]

i got a 90 iroc z as well car starts time to time but cant give gas or she stall thinking throttle postion sensor or idle control valve. wondering if you tried please advise tom

[MurphyIsmyName]

I ohmed out the tps, and it checked good according to the service manual. I have done alot to my car to troubleshoot, and I know the fuel system is now working, but it acts as if it is way out of time, If I unplug the 4 wire connector from the distributer and use an outside fuel source, like a bleed off from my fuel pressure guage, it runs like a top, revs up and everything, but if I plug the 4 wire plug back in it instantly starts popping through the throttle body so bad it shoots out flames from the intake, and wont hardly run at all. I found that the stator, I think that is what it is called... the brown round thing with triangles on top of the pick up coil, well, anyways, it has a crack in it, and I am just going to try and replace the distributer with one that is good, that will eliminate any thing from that area. The only other thing I can think of that could be causing this is problem is the VATS module itself, telling the computer it has the right key, so it can turn over, but not telling the computer its okay to give the car fuel. If I unplug the VATS module, black box I think right next to the computer, there is no difference in what the car does. Yet the security light dont stay on either... ANY Ideas out there?

[wrightz28]

eh, that 4 wire connector is the ESC module put it back. If your trying to run it on base timing, disconnect the tan single wire on the firewall by the heater housing.

[MurphyIsmyName]

Well, I took apart the intake today and Found that every one of the injectors on the left side of the car were so full of crap that there was no way that fuel could have gotten through them. I suspect that the right side of the car is the same way. I havent gotten more injectors yet, they are really expensive, and I have to figure out where they are the cheapest at... But I am hoping this will cure all my woe's.... We will see in the next day or two...