I've got a problem. I've tried everything, but nothing seems to work.

In the past, all 8 plugs would foul out in my 85 Z28 305 TPI.

The engine used to run like crap, but it would run. I had to keep the RPM's up though - it wouldn't idle.

Now, however, the engine is flooding itself out within a few seconds of cranking. I take out a plug, nice and clean, but it's SOAKED to the bone with fuel, and wont fire. If I unplug the injector wires, and try to start it, it fires off like a new engine, then, when it runs out of fuel, it dies.

My question is this: what could be making the injectors flood the engine so bad?

I've confirmed that they are not leaky - not only have I individually removed all of them and done a pressure test on them, but the fact that the engine runs out of fuel when the injector wires are disconnected says that they're good.

I've installed a new fuel pressure regulator, and changed out the ECM.

I'm wondering if maybe the hack that owned the car before me didn't attach a ground that's supposed to be somewhere. And, just for the record, I've replaced just about every component in the Distributor.

Any help or suggestions would be greatly appretiated.

 

O2 sensor?
Any codes being thrown at all?
What's your air cleaner(s) look like?

 

I haven't tried another O2 sensor yet, so I guess that's the next thing on the list.

Another thing I should mention is that she "check engine" light has been flashing very rapidly ever since I hooked up the other ECM. Easily 5 times a second. I would check the codes, but don't have a code checker, and am too far away from the local auto shop to get a reading for me - the car won't make it that far.

And what do you mean by the air cleaner?

 

Get the codes in your garage by using an un-bent paperclip and shoving it into slots a and b of your aldl connector. Turn the car to ON but not running and watch the SES light blink. It'll blink out numbers. The full procedure is in the tech articles.

 

Check your coolant temp sensor, and its wiring.

The ECM may be thinking that it's always -40° or whatever, and fueling the engine accordingly.

If you have the CTS with the round "concentric" sort of connector, then it's garbage. The wiring for that system is TERRIBLE.

Go to the parts store and get a new CTS; it will come with a pigtail for it, which is a completely different style (2 pins next to each other).

Normally, just throwing parts at a problem isn't a great idea, but sometimes, there's a time and a place for doing that. This might just be one of them. Espcecially since (a) it's a FREQUENT cause of similar problems, and (b) those sensors don't last forever ANYWAY, and (c) it's cheap, and (d) it's real easy.

 

That doesn't sound like O2 or CTS to me, as those are closed loop items. If it floods from a few seconds of cranking, something else is wrong.

When you unplug the injector wires and run it until it dies, does it flood again immediately when cranking for a few seconds with the wires reattached?

I suspect there is something else involved that isn't part of this thread yet. You mentioned the PO hacked things up - are you sure you've gotten everything back the way it is supposed to be?

I'm not sure that's a valid test to verify they're good.

 

Alrighty -

Coincidentally, my dad had the same idea that one of you guys did - he thought that the temperature sending unit was telling the ECM that the engine was -40 below zero, and fueling it accordingly. We swapped that out, and the neverending project, as denoted by the gloomy 6 months it was darkening the driveway, came to a halt. The thing took off.

It runs great. After the engine got up to temp, several spark plugs cleaned up, and it sounded even better.

One more thing, however - the coolant fan isn't coming on. It gets up to about 240 degrees, and I shut it off in fear of an overheat. Not sure what the problem is.

I suppose I could hook up a manual switch and put it inside the car, but that would only be a temporary fix. Any ideas anyone?

And thank you all for helping me out on this whole thing.

You guys truly helped me out.

- Don

 

240 is about the fan turn-on temp.

 

I have a '88 firebird as well, and it's fan comes on at approximately 240, and I should have said something other than 240 degrees.

I should have said that the coolant was boiling. It was.

 

240° is fine. No problem. Completely normal. The actual number that the factory fan switch turns on the fan is 235°, actually, but that's well within the tolerances for such things, including gauges.Put a new radiator cap on it, and a 60-40 mix of water and A/F.

People have this idea that water boils at 212°. Well, it's not true. It's only true for PURE water at SEA LEVEL PRESSURE.

A 60-40 mix of water and A/F boils at around 230° at sea level pressure, and at about 265-270° at 16 psi (proper cooling system pressure). In other words, with a bad rad cap, your coolant will be boiling at a LOWER temp than the factory settings. You could take such a bad rad cap, and put it on a BRAND NEW car sitting on the showroom floor, and it would boil over.

Change the radiator cap.

 

I'll plan on getting a new cap, because I'm sure the one that's on the car has been for 20 years, but that's not my problem.

The engine OVERHEATS. The fan WILL NOT come on, as per the ECM, or some other sensor. I can jump the fan. If i put 12 V to the relay, it comes on, regardless of temp.

There's something crucial that I'm forgetting to mention. Whatever.

Something, possibly unrelated, is that when I try to check the codes the ECM spits out when I check them (with a paperclip ;D), they do not appear. Instead of the "Check Engine" light flashing, when I connect the paperclip, nothing with the light happens.

When I turn the key on and connect the paperclip, several relays, including the fan relay, make very loud clicking noises, and power appears to be given to them in pulses - the fan comes on, and flicks off, with every click.

Again, i'll be searching through my own sources, but does anyone have an idea?

 

Change the bulb.

Nothing you've said so far indicates any kind of "overheating", or anything else abnormal, except that the radiator cap doesn't seem to hold pressure thereby allowing the coolant to boil.

What happened when you put in a new radiator cap? Did it stifle the boiling?

 

Alrighty.

Most of my problems appear to be solved now, but there is a new one.

1.) The engine doesn't respond to throttle if it's too quick. I.E.: If I floor it, i seem to have significant power loss after about 2200 RPM's. If I accelerate slow, theres no problem.

ideas?

Anyway,

I replaced 2 different temp sensors, the IAC valve, which allowed for a much better idle, and some other duhikis here and there. I took it for a long diagnostic drive yesterday, and everything appeared to be working.

The reason the fan wouldn't come on: the fuse under dash was missing for it.

I should have checked those fuses first.

One thing, that hasn't appeared to have effected engine performance yet: the ECM won't go into closed loop mode. The check engine light still flashes very rapidly, despite the car being driven at operating temp for an extended period of time.

 

<quote>One thing, that hasn't appeared to have effected engine performance yet: the ECM won't go into closed loop mode. The check engine light still flashes very rapidly, despite the car being driven at operating temp for an extended period of time.</quote>

did you leave the paper clip in the ALDL port?