20B10AE

iTrader: (14)

OK, I'm at my wits end here.

The car:
1988 10th Anniversary with a stock ported 20B being run by an E11v2. Walbro 255 pump, stock fuel system otherwise.

The problem:
The car has been running fine up until a couple of nights ago. I had barely any gas in the car so I put in 2 gallons from a gas tank with fresh gas in it. I started the car and drove to the gas station where I put in another 6 gallons and 6 oz of premix. I drove about 3 miles up the road and stopped to hang out with some people. About 2 hours later we left to go up the street about a mile. The car started with no problem. I shut down and went inside to eat. That took about an hour. I went to start the car again, but it acted like it was flooded. We didn't have tools with us, so we tried push starting and then towing the car to start it. ZERO luck.

The next day I pulled the plugs on the car to check them. They were BLACK with what looked like carbon all over them as if it had been running really, really rich for a while. No problem, I put new plugs in and the car fired up almost immediately. The problem is, it's got quite a bit of smoke coming from the exhaust now. It is super rich, to the point where if you stand behind the car for more than 2 or 3 seconds your eyes are burning and you're choking. Hmmm...

I double checked the timing. Perfect, and all plugs were firing. The car is sitting at a pretty solid 1000RPM idle. I've tried to pull more fuel out at idle but when I do it simply starts hunting up and down. I even attempted to use a zero throttle map. Still smoking like a train. I also made sure that ALL fuel corrections were turned off. The car is pulling just under 500mmHg at idle, which is about what it has always done.

I've tried playing with the car for two days now for a total of about 3 or 4 hours. Last night while working on it, it ran out of gas. How bad is your problem when you use 8 gallons in that span of time at IDLE????

Recap:
Car flooded out. Swapped in new plugs and started car. Super rich and smoking from excess fuel. No settings made a difference. Used up 8 gallons in about 4 hours of idling.

Can a fuel pressure regulator go bad in this way? I tried a different MAP sensor but it wouldn't even allow the car to start, so it may be bad. (The car is set up using a stock TII MAP sensor. The one I tried swapping in was a 318.

Ideas and/or solutions would be great!

Reese

RETed

Yeah, I'd say something weird is up with your fuel system / FPR.
Adjusting the fuel maps implies that the fuel injectors are changing duration, so I doubt if they are sticking.
*tsk tsk* You should be running a fuel pressure gauge by now.


-Ted

20B10AE

iTrader: (14)

:hanging head: I'm sorry, Ted! I'll try to get one installed ASAP! Heh.

Claudio RX-7

iTrader: (1)

Yes, i concur with Ted, if everything is fine with the mapping and the car runs right, and all of a suden you get to rich a mixture and fowled plugs then something is up with the fuel system. Id check fuel pressure, then see if the pump is working right, install a gauge so you see whats going on, and then in the worst of cases an injector is stuck opened. On every new installation i do the first thing i have the client do is clean the injectors so they are at 100%, and make sure we have a way to read fuel pressure, boost and EGTs, cause the better informed you are the easiest it will be to troubleshoot.

I had a TurboII work fine for a half an hour once, and then the car just ran like crap i kept pushing fuel in with the maps and it just kept getting worse and worst, i turned out to be that they owner of the car had his fuel pump (an SX model) installed with bigger lines and no fuel filter! :S so that just clogged up the injectors instantly.

And on my personal 87 Turbo, the fuel pump died on me, the car started but burped and stumbled all the way, when i looked at the pressure gauge, bingo, no pressure.

Some food for thought.

20B10AE

iTrader: (14)

Thanks, Caludio. What puzzles me is that it seems to be perfectly fine idling along even though it's throwing that much additional fuel through. Shouldn't that extra fuel be causing it to die or at the very least run roughly?

Just a couple more hours until I can go try to check fuel pressure assuming I can find a pressure tester around here. I went to Pep Boys at lunch but they only had a low pressure tester for carbed setups.

Reese

Trevor

Pretty obvious here but check the vaccum reference line that goes to the FPR too. If it popped off you'll be roughly 11% fatter at idle.

Claudio RX-7

iTrader: (1)

Just another shot in the dark here, what kind/condition are you plugs in? and how much boost are you runing?

20B10AE

iTrader: (14)

I just swapped in brand new plugs. I haven't driven the car since I noticed teh smoking, but I was running about 10psi.

20B10AE

iTrader: (14)

**UPDATE**

OK, I went to get a fuel pressure tester today, but the only ones available were Schrader valve-type. I don't see any way to use that on our fuel rails so no pressure test was done.

I did try running some injector cleaner through, but nothing came of that.

I pulled the fuel rails off to generally check things out. The only abnormal thing I saw was on one of the primary injectors. I'm not really familiar with the way side feeds look since I'm a second gen guy, so I'm not sure if this is abnormal or not. When looking straight down at the top of the injectors you can see a metal ring that is the top of the body. Inside that ring is a piston . Sorry my terminology stinks here. Anyway, the inside of the ring is tapered a bit. Two of the inner 'pistons' are flush with the bottom of the tapered area. The third is sitting flush with the top of the ring itself.

I included a bad drawing to try to clarify a bit. My question is, "Does what I am seeing indicate that the odd injector (or the other two) is stuck partially open? Is there a way I can fix this myself?

Also, does anyone have a suggestion as to how I can check the pressure with or without a Schrader valve tester?

Reese

20B10AE

iTrader: (14)

Well, here's an update of sorts...

I pulled both fuel rails off last night so I could put voltage to each injector to see if they were stuck. All 6 clicked when I put the battery to them so at least they aren't stuck. I cleaned them up to get rid of some of the crap that was built up on them and put them back in this evening.

I borrowed a fuel pressure tester from a friend of mine. At idle the fuel pressure is a steady 37 psi. No variation that I noted. This kind of puts me back at square one. I rechecked to verify that there is no form of fuel correction turned on.

What does this leave me with? It still idles fine. The timing light shows that all plugs are firing fine. It still smokes and reeks of fuel way more than normal. Oil and water levels are fine. The fuel pump and fuel filter are both fine. I'm pulling about 480 mmHg at idle. Pulling any more fuel out at idle still causes it to 'hunt'.

Sigh...I was hoping that I'd have an answer by now...

Reese

RETed

Okay, if the fuel side looks kosher, time to check the ignition side...
Verify all the spark plugs are firing?


-Ted

20B10AE

iTrader: (14)

Learn to read, Ted!!

Seriously, i've reloaded my maps twice hoping that it was a software glitch, but timing seems to be dead on. Want to check my map?

Reese

RETed

hhaha, no, that's not what I mean. :P

Could there be a problem with arcing?

max brought up an interesting test about spraying water around the coils and the spark plugs / wires to see if the fine mist could induce an arc.
If there is arcing, this would wreak havoc on the ignition system and kill power.
Lower power means the engine has to work harder to maintain speed and power.

Worth a try?

BTW, what's your spark duration?
4.5ms - 5.0ms?
If the spark is blowing out under load, then you're also losing efficiency.
It might be worth it just to bump up the spark duration to see if this helps?
Just idling is just about the best case scenario for the ignition spark - very little load, and very little ionized gases are produced.
Once the engine is loaded, it gets harder to trigger the spark.


-Ted

Indian

iTrader: (1)

WHat about a gas Leak?!??!?! :S

ShaunO

I have nothing constructive to add here, but I do have a question...

20N10AE mentioned "I did try running some injector cleaner through, but nothing came of that". Is there any merit to this stuff, or is it just snake oil? I remember a guy trying to sell me some at a quick lube shop, and the price was ridiculous. As I recall, I think it was like $50CDN.