timonator

iTrader: (4)

My daughter and I picked up an 86 IROC-Z project car for her,that was sitting for quite a while,that we are trying to get running. I just finished replacing the fuel pump. It will start and idle for a minute and then it dies or it dies as soon as you try to give it gas. I noticed that The fuel pump will run for a few seconds when I turn the key on, or it will run when cranking the engine over. what i think is happening is that the fuel pump is not continuing to run after it starts. So, if anyone knows what my problem is or has any ideas I would greatly appreciate the help.
Thanks,Tim

timonator

iTrader: (4)

Also, the fuel rail doesn't hold pressure.

puddingmmmmmmmm

iTrader: (5)

Sounds like leaking injectors. Double check your injector fuses also, if they are okay, I would start to ohm test the injectors using a volt meter. Cold the injectors should test between 11-14 according to haynes manual. anything lesss than 11, and it's bad.

timonator

iTrader: (4)

I found out the alternator wasn't charging. Changed it out to find out the new one was bad too. I won't get the replacement one till tonight.
The car was sitting xxxx number of years so we don't know what all is wrong with it. The first thing we had to do was put a fuel pump in it. I guess Ill see how it does after I put the new alt. In. I will make sure to ohm out the injectors too. Thanks for the info.

southbay08

www.southbayfuelinjectors.com

timonator

iTrader: (4)

All the injectors are between 16.2 and 16.4.

southbay08

pull the plugs, if you have wet cylinders you have leaky injectors

puddingmmmmmmmm

iTrader: (5)

If they are the stock injectors, there's a really good chance some of them are probably leaking. I bought a set of the injectors from southbay for like 120, I love them, no problems what so ever from the injectors so far.

If you have a 305, and don't want to spend a ton on injectors I highly rec. these injectors.

http://www.southbayfuelinjectors.com...o_305_TPi.html

timonator

iTrader: (4)

I was going to change the plugs and wires tomorrow anyway. So I'll see if they're wet then.

1987CamaroZ28

Tim, did you figure it out?
Not to hyjack your thread, but I'm having a similar issue, but the conditions seem to be different.

I just finished putting the engine in the bay and wired everything up. I put a new high pressure Holly electric pump in the tank. I'm getting fuel to the rails but my fuel pressure gauge is not registering. The injectors are new. when I pull the fuel pressure gauge line off the fuel rail, there's a little gas that comes out, but not with any pressure. I had the fuel filler cap off, and only the feed and return lines are hooked up. The other two lines (vents) are not.

timonator

iTrader: (4)

Ok, I changed the plugs and they were all dry except #5 which had a broken plug wire. They were all very black though.

Chevy86 IROC-Z

iTrader: (17)

i got a 86 IROC-Z, except that I got a 350. If your losing pressure fairly quick in about 1-5 minutes, then you have 1 of 2 problems, a leaking F.I. or a bad Fuel Pressure Regulator. The diaphram in the FPR housing is more than likely rotting and cracked. To do a quick test, turn on the Camaro and let it idle for a minute. turn it off and pull the Vacuum hose that is connected to the FPR housing. Now lean forward and sniff the hose. If you smell the distinctive smell of gasoline, then you have found your source of dropping fuel pressure. Replace if neccessary. If there is no smell of gas, then your culprate is the F.I.. Southbay is a sponser here. I suggest getting the Newly modified 19 LB Bosch III injectors for around $150. Dont get the 22 lbs because they are for the 350 block with a 350 PROM chip. Your 86 IROC has a PROM chip for a 305 (unless it was switched out prior to your Camaro purchase). To investigate if you have a 350 PROM chip, pull the ECM, remove dust cover, write down the numbers that are stamped on the PROM, and run a check through the search tab here in thirdgen.org. Also when you turn the key to on, and you hear the fuel pump wind then stop, it's normal. The pump is charging the fuel system pressure. Usually you'll hear a click when this occurs. The click that you hear is the Fuel Pump relay that is located next to the brake booster. Now when you turn off the Camaro, it is normal to hear the click or clicks and of course the Fuel pump charging agian. The clicks that you may hear are the fuel pump relay tripping agian (normal) and the Mass Air Flow Burn-Off relay. The MAF Burn-Off relays job is to send a 12 volt charge into the Mass Air Flow Sensor just infront of the trottlebody. The little wire that is inside the MAF Sensor then glows red hot so that any forieghn material can be burned off. This is just to inform you if you get curious from hearing clicks when you turn on/off the IROC. If you need anymore help, let me know and Ill help you out to the best of my knowledge. Food for thought, if you dont hear these clicks, it's probably because you got aftermarket relays. Good Luck man. It's a gift from you, to your child and I know that means much to you.

Chevy86 IROC-Z

Chevy86 IROC-Z

iTrader: (17)

Also, when you turn on the IROC, does your "Service Engine Soon" light stay lit? If so pull the troublecodes and let us know what you find so that we can better assist you. Here is the link so that you can learn how to pull the troublecodes.
http://www.gnttype.org/maint/malf.html

timonator

iTrader: (4)

Well, I finally got it to the point where it will idle. But as soon as I open the throttle body it wants to die instantly though I can get it to rev up if I slowly open the throttle body. For some reason it idles at 1900 rpm and will sometimes backfire when I rev it up.
Over the course of the weekend I replaced the plugs and wires, fuel pressure regulator diapragm although the old one looked ok, replaced the upper intake gaskets and injector o-rings,soaked the injectors in injector cleaner,replaced the egr valve,the throttle position sensor and the IAC valve.
I have no check engine light on either. I will probably check it with my scanner tomorrow anyway.

puddingmmmmmmmm

iTrader: (5)

when you replaced the TPS did you adjust the IAC valve and TPS properly?

renemedrano842

iTrader: (2)

might want to verify your timing 6deg btdc works pretty well. When you replaced the fuel pump did you make sure to buy the one for mpfi and not just fi. the tbi fuel pump doesnt pump enough pressure to run 8 injectors. Happened to me once i thought i was getting a heck of a deal on a pump.

timonator

iTrader: (4)

when you replaced the TPS did you adjust the IAC valve and TPS properly?
__________________

No,not yet

timonator

iTrader: (4)

I Will also be checking the timing tonight. I hope they sold me the right pump. It was like $80. When you look up parts for the car they only show one version of f.i. for a 5.0.

John 89 Formula

While it is idleing tap the maf sensor with the handle of a screw driver, if the engine stumbles your problem is maf related, you may want to change out the maf relays anyway just to be safe.

timonator

iTrader: (4)

[QUOTE=John 89 Formula;4539709]While it is idleing tap the maf sensor with the handle of a screw driver, if the engine stumbles your problem is maf related, you may want to change out the maf relays anyway just to be safe.[/QUOTE

I did try tapping the MAF. There was no response.

John 89 Formula

You should probably change the cap and coil as well, if you haven't done it already that is.

timonator

iTrader: (4)

Normally those would have been one of the first things I attacked, but the cap&rotor look brand new plus the spark looks really good.

Chevy86 IROC-Z

iTrader: (17)

You should change out the pickup coil inside the dizzy. they usually get all gunked up with grease.

timonator

iTrader: (4)

Where can. Get that? I didn't know they were serviceable.

Chevy86 IROC-Z

iTrader: (17)

It's not service able. They are under $30 dollars at the parts store. The problem is that you,ll need to mark and REMEMBER the position of the rotor. It would be wise to remove the cap, take a picture of where the rotors position and the dizzy is at so that when you put the dizzy back into the engine, you'll know. Make a mark at the base of the dizzy and at the block, where the hold down bolt is at with a permanent marker. When you get the dizzy out, you'll need a degreaser such as carb cleaner because there will be so much junk on the shaft that it'll be tough to pull out the spinning rotor shaft from the dizzy. Before you do all of this great stuff, take your time. YOu can buy the 7-pin Ignition Control Module if you want to since the dizzy is out. Find a punch and pound out the pin that holds the gear at the bottom of the dizzy. once the gear is removed, move on to the next step. Now remove the ICM and the RF capacitor. Now spray carb cleaner down into the shaft from the bottom. let it drip at the other end. Now pull and twist the shaft up and out. It may be very hard to pull out because of the grime. Once out, There is a small c-clip pin that is barely noticeable that holds the pick up coil in place. then remove the dirty coil and replace with new on. Now when you put back together, coat the rotor shaft with motor oil (preferably grease) before you insert it back into the dizzy.

Here is what the pick up coil looks like

John 89 Formula

what condition is the fuel filter in? If it's old it could be restricting the flow.

timonator

iTrader: (4)

I think you're right about that. It looks new but the old fuel inside is probably hard as a rock and plugging it up.

timonator

iTrader: (4)

I ajusted the timing,the tps and iac. I noticed that when I unplug the maf it runs a hundred times better. But it still wants to die when i give it throttle. I also noticed that it doesn't want to start cold.It seems I have to give it a shot of starting fluid to get it going. Oh, I also changed the fuel filter,though I don't think it made any difference.

kjvail1204

iTrader: (4)

Check the PCV valve in the Valve cover and also is there a strong exhaust coming out the back, sounds like you have fuel and fire, but its not breathing right.

John 89 Formula

Replace your maf sensor power and burn relays, also check the wiring on the connectors, over time the insulation slides down leaving the bare wire exposed which could also cause problems.

timonator

iTrader: (4)

Looking at the wiring schematic, there is only a burn off relay for the MAF. Am I missing something ?

John 89 Formula

there should be 3 relays on the firewall near the brake booster 1 is the f/p relay the other 2 are for the maf sensor, but I'm not sure which is which. if they're original the power relay will say right on it "power relay" in red letters

timonator

iTrader: (4)

Ok, I'll take a look when I get home.

timonator

iTrader: (4)

Well, I didnt get to the MAF relays yet but I got my new fuel pressure gauge. When i turn the key on to let the pump prime and the relay clicks I walk to the front of the car just in time to see the gauge drop to zero. When I start the car it never gets over 28. If I pinch off the return line and jump the relay the pressure never gets over 28 and drops like a rock when I take the jumper off.

John 89 Formula

Time for a new fuel pump, the pressure should be around 40-45 lbs it will never run on 28

timonator

iTrader: (4)

Ya, that fuel pump is junk. I just replaced it.

Chevy86 IROC-Z

iTrader: (17)

You must checkout a wiring diagram. Out the factory, the relays where in order. But remember, our 3rd Gens are around 1/4 century old or more. The relays have probably been changed or switched around. So there is no definate way to verify which relay is which. Thee only one that is verifiable by number of wires is the 4 wire relay which happens to be the MAF Burn-off Relay. Also the main difference in the relays are a resistor. The MAF Power Relay (OEM) has a resistor that runs around the prongs. Now for the FP relay, there is no resistor. But If you buy a FP relay at Autozone, they carry a resistor. In other words, the resistor is there to prevent an arc which can weld the contacts together resulting in a failure depending on which component that is connected to that affected relay. Below are the links that you can use to reference your 1986 305 IROC-Z. Enjoy.

1. Fuel Pump relay wiring diagram - http://92b4crs.tripod.com/86wiring/dia-pics/22-2.jpg

2. MAF Burn-Off Relay and MAF Power Relay - http://92b4crs.tripod.com/86wiring/dia-pics/22-5.jpg

menace156

Well tim, I am having the same problem with my 85 trans am, same motor and all. I replaced the fuel pump and starter, checked the injectors and replaced the cap and coil. The only problem with mine is that i cant even get it to crank over except with the starting fluid and even then its a struggle. There is no fuel pressure for me either which is discouraging. I would really love to know how you fixed the car, if u have yet or not, and all the thigns that you have done to it because as i have said its the same thing for me only about twice as bad.

timonator

iTrader: (4)

I changed the pump again last night. I now have 39 psi at idle. Istill have to put the panhard bar and shields back together tonight. Also put in new connectors for my MAF and TPS. It still runs like crap, but I'll get it there eventually.

timonator

iTrader: (4)

Well, i guess it's the end of this thread becauase the car will now STAY RUNNING ! It's not perfect yet but it runs pretty good now. So, I would like to say thanks to everyone here that gave me helpful advice.