Svelte_SS

Apparently my car is running richer than Bill Gates. My plugs get completely drenched in gasoline in about 2 weeks time. What is usually the main cause of this?

I searched and found out about a possible bad coolant temperature sensor can cause excess fuel to be dumped into the cylinders so I replaced that but it's still fouling.

If it was the injectors I'm thinking that it would just be two or three that are getting fouled, not every single one.

I'm running an AFPR that is now correctly set at 42 psi. It was high as 55 psi at one time maybe even a little higher because I didn't know you had to set it with the vaccum line pulled and plugged so I had it set at around 50 psi with the vacuum line still on, which was probably close to 60 psi at one time without vaccum.

Is that enough pressure to blow the injectors or the AFPR? Is there a way to test my AFPR to see if it's blown or something? If it was, wouldn't it show in on the pressure guage?

blown_z28

You and I run about the same setup, I noticed you don't say anytihng about your O2 sensor. When I switched to a dual exhuast setup my car would fowl the plugs really fast and the problem turned out to be the O2, I had to switch to a 3-wire heated sensor because the headers weren't retainning enough heat for the sensor to function properly, so the ecm would dump way to much gas thinking the car was still cold. Hope this helps.

Svelte_SS

Ok I went and bought a 3 wire o2 sensor. The thing is I have no idea how to hook it up. It has the black wire (signal) and two other white wires. Do I just run both of these to +12v ignition or what?

Fire"Dutch"Bird

iTrader: (1)

What brand and heatrange plugs are you using?
I had trouble with fouling plugs as well,the Bosch +4 were very bad,so I changed to AC R43TS (as the handbook says) they were to cold, so I went for AC R44TS that was somewhat better,now I'm running AC Rapidfire no2,no more fouling anymore!

jmiller

The 3 wire O2 sensor must have 12 volt ignition and ground hooked to the remaining 2 wires. You also might want to check to make sure none of your injectors are jammed in the base manifold causing the injector to not shut off. Or you may have some that are simply not shutting off between pulses. Make sure you can turn them while installed.

Svelte_SS

I'm running the AC R43TS. Hmm, I guess I'll give the rapidfires a try. What's the price difference? What are you gapping them at?

Svelte_SS

They are both white wires. Which one is ignition and which one is ground or does it matter?

I'm pretty sure all my injectors can turn because they were twisting when I was installing and removing the injector tester harness...

Fire"Dutch"Bird

iTrader: (1)

The AC Rapidfire plugs are factory gapped!
No need to change that !

jmiller

Doesn't matter which one you use for ground or ignition. The reason for doing this is a three wire O2 sensor has a heater element built in to preheat the sensor. They are a must have when using headers.

Svelte_SS

Sunuvab!tch , I installed the rapidfires and 3wire o2 sensor and took it for a drive and she drove worse than ever! Still dumping copius amounts of fuel, still have huge black trails of smoke that reeks of gas coming out of my exhaust. Still idles very sickly and choppy. It would just barely idle around town. If I tried to give it more than 10% throttle it would just backfire. If this car was a horse I would've shot it already....

jmiller

Most of us on this board would love to help you, but we don't have a clue to what you have and what you have done. It might be time for you to think about what you have changed since the last time it ran ok. You are definitely getting too much fuel. Did you change injectors, did you rebuild the engine, did it ever run right for you? We don't know any of this. Having the wrong heat range spark plugs won't cause your problem. If everything in the motor is installed correctly, cam timing, ignition timing etc., then I would say it must be your injectors are not shutting off between pulses. If the tip of the injector is jammed into the base manifold, it can't shut off. Did you remove the injectors and reinstall them? If so, did you put the seals on them and install them correctly? Are you using a stock manifold base?
john miller

Svelte_SS

I've never removed the injectors.
I've never rebuilt the engine.
I've never removed the runners or manifold, all stock...
It was running fine a couple months ago.

I did turn it over once without the spark plugs in it and I did see what appeared to be normal spray pattern coming out of the holes, not continuous as it would be if they weren't shutting off...

jmiller

OK, then go over everything you have changed since it last ran ok. More than likely it is probably something you changed, rather than something just dieing. We have all been in the same position as you at one time or another. If you are sure it is not the injectors, then start looking at the ignition system. Make sure you are getting a good spark. Then check everything in your air intake system for restriction. Are you getting an error code?

Svelte_SS

I had a friend hook up a scanner and it did say there was something wrong with the ignition, but I am getting good spark so I don't know if that's my main problem...

I tested my MAF signal pin at the ECM and got a 2.42 v reading.

Isn't this supposed to be between .5 and 1.0 v?

Could this be my problem?

JAKEDPLAYA

I doubt it...but unplug it and take her for a spin

jmiller

I don't have that info in front of me right now, but if you are right, then the MAF could be sending a signal to the ECM that is way off, causing the ECM to add too much fuel. I have been using an auto-Xray scanner for years now on both my cars. I have an 87' IROC 383TPI and a 67' Camaro ZZ4/TPI. Anyway, what I rely on when I make changes that can influence air/fuel ratios, is check the MAF reading grams/second and the O2 sensor mvolts. At WOT O2 readings should be somewhere between 700-900 mvolts. You can raise and lower fuel pressure as needed. I have found that 50 lbs on my IROC is app. 875 mvolts. I lowered it to 47 lbs. and the number dropped to 830 mvolts. I will check tonite to find out what voltage the MAF should be sending with ign. on not running. I suppose that's how you checked it.

Svelte_SS

Why would you check it with the engine not running? There would be no air moving over the sensor so what good would that reading do you?

jmiller

If you were getting that reading with the engine running, how would you know what to compare to. I'm confused with the way you checked it, because I always do scans while driving my car at WOT and looking at grams per second, not voltage.

Svelte_SS

I just read somewhere that it's supposed to read 0volts with ign on and between .5 and 1.0 volts with the engine running.

Anyone else?

Svelte_SS

ttt...