Car won't start floods out.

[darock]

I can not get my car (3.1 MFI) started, it floods out. It floods so bad that I get fuel running out of the throttle body, not sure if it is the fuel pressure regulator or my timing jumped a cog.
I bought this car last summer for $250. They thought the ECM was out it has 216K miles on it, but uses no oil and runs fairly good when going down the road. I got an ECM from my brother in-law and changed it but I never could get it to idle. I changed the IAC, TPS, O2 sensor, PCV valve, Plugs & Wires.
I do not have a fuel pressure gauge, yet, and I can't find any timing marks on the harmonic balancer to check timing. So I am not sure where to start, looks like the fuel regulator is about $100. and timing gears and chain not cheap either.
If someone has any idea what my problem is it would be greatly appreciated.

[jeffcoslacker]

Disable the injectors and see if it seems to run right on some starting fluid, then you could rule out a slipped timing chain. Then you'd need the fuel pressure gauge to check the regulator, pinch off the return line with the key on, if the pressure shoots up, its bad. I've seen them flood like that when the coolant temp sensor dies. Just a thought. It must make the ECM think it's really cold out, and command full rich.

[Carwhiz]

Before you get carried away replacing unneeded parts, have your computer re-programmed. When the early 90's ECM's are disconnected from power for a period of time they are not able to reset themselves like newer computers are. A common problem is the car is unable to idle, and runs rich. GM dealers only charge about $30 bucks to reprogram the ECM. If the pressure regulator is bad, go to AutoZone, it is a lot cheaper than 100 bucks!!!

[darock]

I have been busy this week and haven't had the time to do much with this. I was hoping to get it started so I could get it in my garage. I did try to start it after shoveling snow (thank God spring is here) I tried Jeffs idea and pulled the injector fuse under the hood but it seemed to still be getting fuel. What really bothers me is how does the fuel get in the intake unless the timing was off and intake valves are open during compressions stroke. Even if the fuel regulator was bad you'd think the fuel would go straight out the exhaust. I live in ND and it was cold the week it quit -25 to -30. It tries to fire a bit if I hold the throttle wide open and after cranking on it for a bit I open up the throttle and about a 1/4 cup of fuel runs out of the throttle body, that seems like a lot of fuel.

Thanks for your replies Guys

[kudude]

Originally Posted by darock

I have been busy this week and haven't had the time to do much with this. I was hoping to get it started so I could get it in my garage. I did try to start it after shoveling snow (thank God spring is here) I tried Jeffs idea and pulled the injector fuse under the hood but it seemed to still be getting fuel. What really bothers me is how does the fuel get in the intake unless the timing was off and intake valves are open during compressions stroke. Even if the fuel regulator was bad you'd think the fuel would go straight out the exhaust. I live in ND and it was cold the week it quit -25 to -30. It tries to fire a bit if I hold the throttle wide open and after cranking on it for a bit I open up the throttle and about a 1/4 cup of fuel runs out of the throttle body, that seems like a lot of fuel.

Thanks for your replies Guys

I'm having the EXACT same problem. My friend need his car to get back to work, and its doing this. Does anyone have any ideas?
thanks
jesse

[kudude]

Originally Posted by kudude

I'm having the EXACT same problem. My friend need his car to get back to work, and its doing this. Does anyone have any ideas?
thanks
jesse

Well i fixed. For posterity, I'll give you the run down.

If it's flooding out of the throttle body, it might be the fuel pressure regulator. With this part bad, even with no connectors on the injectors, power to the fuel pump will cause fuel to spill out of the little black hose running from the regulator to the throttle body, thus flooding out to the intake box.

If first make sure the fuel is coming from the malfunctioning regulator. Basically, if you remove the air intake tube (only need a flat head screwdriver) here's how you can test. Have someone turn the key to on (not try to start it, but just so the battery hits the fuel pump and you hear it whirring). While this is going on, pull on the throttle cable to open the butterfly valve. If fuel comes spilling out while you are just sending power to the fuel pump, and not cranking the engine your problem is probably the fuel pressure regulator. For me it was $103 at autozone.

A real test involves doing the same thing, but pulling that thin black plastic hose that goes into the throttle body from in between the plenum and the engine. If you just pull that out, and do the same test, the fuel should now spill all over the top of your engine. Enjoy.
If it does, just go ahead and buy a new regulator.

I'm not sure why there was no core, as it's a hunk of aluminum, but the manufacturers in their infinite wisdom decided a bad one was worthless.

At his point, you should disconnect your battery, just because. When I did it, i didn't remove the airbox (there are only two bolts holding it in) and i almost fused the crescent wrench i was using to the bracing bar that goes over the battery. I recommend removing the airbox.

Here's how you replace it
1) remove plenum. Easier said than done. There are 8 (or something) bolts on top you need to remove. Also remove the two bolts holding the throttle body to the plenum. there are a couple of things connected to the back of the plenum. Remove the three botls/nuts that appear to be the most in the way. As i recall, you should be able to lift the plenum up now, but you don't actually have to remove it, just give yourself enough working room.

2) There are two hydraulic lines (fuel lines) that run to the fuel pressure regulator under the plenum. The regulator is the aluminum piece in between the two fuel rails that has the fuel lines running to it (duh....). Take off those hydraulic lines, as well as the one that you probaby already had to remove to get the throttle body out of the way. Also, those three hoses that run into the top of the throttle body that are connected by the rubber piece on the intake of hte throttle body should be popped out of the way.

3. Okay, here's the fun part. You need to take off the four bolts holding the fuel rails down to give yourself a little wiggle room. Also remove the 6 torx bolt/screw-thingys that hold the plate to the rails/regulator. Now there is nothing holding the regulator in but some o-rings and friction.

4) Pull the rails apart and get the regulator out of there. Don't hurt the injectors (although i was far from careful, and mine are fine). There are two small cylindrical pieces which are connecting the regulator to the rails. They need to come out (they were still stuck in my old regulator) and be put in the NEW regulator. replace the o-rings if you wish.

5) now pop the new regulator back in. Uh, easier said than done. You'll find that compressing orings seems to make then NOT want to go where they're supposed to. I ended up (as per suggestion from my dad) smearing the rings with vacuum grease. They popped right in.

6) Reconnect everything. in reverse order. Should take about 20 minutes. Some probably suggest replacing the gaskets under the plenum and between the throttle body and plenum. I didn't, and they work fine. YMMV. Make sure you get the fuel lines in tight, and rewrap the wire to the injectors if you feel it necessary (i did). Be careful when replacing the plenum that you don't smash any wires, or you'll be sorry.

7) Fire it up with the air intake disconnected and see if fuel is still spilling out. If it is, i'm sorry.

8) put the air intake tube back on and go for a test drive. Mine smoked like hell for a few minutes, probably from the vacuum grease. After that it ran like a champ and still is.


9) be glad that you spent $100 on a part at auto zone and not $200 in parts and $250 in labor at your local dealership.

[jeffcoslacker]

Thanks for the feedback! Glad you got it figured.