Real Fiero Tech

Yep yep, this topic again. Dunno where it went... maybe I posted it on Pennock's Fag Forum the last time?

Well, so here's the reader's digest version, because I'm a lazy fuck and nobody likes reading 50 pages of bullshit.

My Fiero doesn't like starting. More specifically, it has "moods". Some "cranks" it'll start right up at the touch of the key. Some days it would crank, crank, crank, I'd stop, then touch it again and it'd go. Sometimes right after I let off the starter and the engine almost stops, it'll catch and fire right up. Yeah, go figure. This happens no matter what... hot weather, cold weather, cold engine, hot engine. It happens anywhere and any time, the same "random" way. There's no pattern.

So far the diagnoses (plural of diagnosis?) have ranged from anything to everything. Coil, injectors, battery, ECM, ignition module, fuel check valve, fuel filter, fuel pump. Might as well replace the whole fucking engine while I'm at it? Or keep the engine and swap a new car under it? Hah. No... so with all these diagnoses (?), I've not yet been able to decide on one.

Until recently of course. About 3 or 4 days ago, I went to start the car, and the typical "no start" crank continued on... and on... and on... across about 16 starting attempts, until it finally started and ran fine. WTF! Cause for alarm, just sort of, but it started again later just "normally" (with 1 or 2 cranks). For the next few days everything was fine. But today... all hell broke loose. It did it again, and after about 8 starting attempts, I started to listen for the fuel pump. I click the key to "Run" and instead of hearing the usual toning-down "WHIRRrrrrrrr..r.r.r.rrrr click", I hear "Whrr....IIirrr.... *CLUNK!* ... Irrrr... rrr... *CLUNK!* rr... *click*". That same noise occurred immediately after letting off the starter as well. I went back to the engine and unscrewed the fuel rail test port cap, and with the key in Run, I pushed the button. Zippo, nada. In fact, I heard a slight "pssshh" as air let the fuel escape. Wtf?? The very next crank, after letting off the starter, the engine caught and ran.

Fuel pump. Right? :thumbleft:

Its strange that a fuel pump would do that. Its a positive displacement pump, they usually work or don't work.

When you get your car to run, does it run normally through all rpm ranges?

Your fuel pump will only run for a few seconds when you turn the key to pressurize the fuel rail. Stopping after a few seconds is normal.

I am almost thinking that you might have a leaky cold start injector. If your fuel rail looses pressure that quickly, it could be leaking out the injector and would cause for hard starts because you are always starting flooded.

Next time you start your car and its taking a while, try putting the petal to the floor and cranking. If it starts easier then you are definitly flooded.

These cars are famous for a leaking cold start injector which is essentially a 7th fuel injector that richens up the air/fuel mix on startup for easier starts.

Do you smell fuel when cranking for that long?

Tried the gas pedal thing... never helps. Sometimes I just do it out of frustration... >.<

Ah, and that was another thing that was on the list, the cold start injector. It does run somewhat rich, but the engine would be running a hell of a lot worse if fuel were leaking out that injector at the rate which it did to lose the pressure that fast.

But what about that supremely fucked up noise? I mean, it did NOT sound happy. I honestly have not the slightest idea how the fuel pump works, but I'd think that a motor with a dead bearing would do the same thing any motor would - work sometimes, and not work other times (as it grinds/rattles itself to death)... :scratch:

Two big problems with my car that I'm really not looking forward to having to fix myself. =(

edit:
Oh, and those other questions... yeah, it runs great once it starts. It does sometimes act weird though. 99% of the time, coming off a stop light or other complete stop, pressing on the gas pedal results in an expected burst of power, a total LOSS of power, then continuing the power once again - like the jolt from the car knocked my foot off the gas pedal or something, but it was in the same position the whole way. But it rolls great, cruises that is, and gets "average" miles per gallon (17.8, 18mpg average). And I didn't notice a smell of gas while I was cranking it a million times today either... it also didn't even try to fire up, it just cranked like I was out of gas. :scratch:

check your timing and your coil.

...

I'm 99.999999% certain it'd be the pump. How can you say timing when there's that god awful noise coming from under the car before I start it? And it runs pretty much fine? :scratch:

I recall testing your fuel pressure a few months ago for you when you were down at the WCF BBQ and determined that you have a leaking injector (probably the cold start). Did you fix that?

Wow, that was you? :salute:

Actually, no... thanks to the plethora of various totally unrelated "diagnoses" I've gotten from other people, the lack of money, plus the lack of availability of the infamous injector, I've been stuck twiddling my thumbs. =\

(edit:)
But seriously though. Zero pressure when the key's in "run"? Shouldn't the fuel pump be running, maintaining pressure? And above all, that god awful noise? Only one thing in that car makes noise under the car without having the engine running... that I know of... :scratch:

disconnect your cold start injector from the electrical plug. Maybe its getting a pulse to fire so its opening. Wouldnt' hurt to try.

If you think its a injector leaking, take off the upper plenum and fuel rail but leave all the fuel lines connected to the rail. Prime the system without starting it of course, and see if you see any fuel dripping out of any of hte injectors.

Hrm, that sounds like a decent test. I guess I could try that. =P

As a relation to what I'd been guessing, I hopped in my car today (after a quick run-around to see if I could find anything relating to my other topic in the tires) and hit the key to Run. I heard the pump go "Rrr, CLUNK, Rrrrrrrrrrrr....", and right when I heard "Rrrrrrrrrrrr....", I hit the starter. It started right up and ran great the rest of the way. :blah5:

Okay, so that Fiero guy here in town came out (okay, he called me... I wasn't running to someone else for advice) and we shot shit for many minutes. He says beyond a shadow of a doubt, now with the noises, that it's the fuel pump. So I'm gonna go for the pump. It could use a new one anyway, it probably hasn't been replaced in all 158,000 miles of the car's life... :thumbleft:

If I do get through replacing it and I still have starting problems, all rights are given to the people here to throw vegetables and mock me mercilessly. :thumbleft:

Series8217 wrote:I recall testing your fuel pressure a few months ago for you when you were down at the WCF BBQ and determined that you have a leaking injector (probably the cold start). Did you fix that?

What is the test for a leaking injector short of removing them? I may have this problem also.

Poking the little thing in the top of the fuel rail and watching what the liquid gold does, apparently. :salute:

You mean the Schraeder valve? I have a fuel pressure gauge I used to test my Pump, is there a specific test to find if the injectors are leaking?

Falcon4: If you haven't done the pump before here's a guide on my site that may help out:

http://fierodomain.com/content/view/111/100/

I always LOL the living shit out of this step:

1. Relieve Fuel Pressure:

* Remove the Fuel Pump fuse and start the car. Allow it to stall, repeat until the car will not start, then turn the engine over for 3 seconds.

My car has no pressure ***IMMEDIATELY*** after turning off the engine! I'd call that "an unnecessary step". :rotflmao:

THANKS for the guide though! It's really going to be useful! I'll bet if there was a step by step guide for replacing a head gasket, it'd be 150 pages long. :thumbleft:

Falcon4 wrote:I always LOL the living shit out of this step:

My car has no pressure ***IMMEDIATELY*** after turning off the engine! I'd call that "an unnecessary step". :rotflmao:

The guide was not written JUST for you. Believe it or not, there are other people in this world beisdes yourself.

Falcon4 wrote: My car has no pressure ***IMMEDIATELY*** after turning off the engine! I'd call that "an unnecessary step". :rotflmao:

You also have a leaky injector :thumbleft:

My car retains pressure even after this step, though not enough to run the car fuel will spray out of the schraeder valve when its pressed.

Xanth wrote:

Series8217 wrote:I recall testing your fuel pressure a few months ago for you when you were down at the WCF BBQ and determined that you have a leaking injector (probably the cold start). Did you fix that?

What is the test for a leaking injector short of removing them? I may have this problem also.

Put a fuel pressure gauge on the fuel rail, then run the fuel pump (turn the key to run). When the fuel pump turns off watch the pressure.. if it goes down quickly you have a leak somewhere.

Mine does go down, but not very fast. I can see it drop.

Xanth wrote:Mine does go down, but not very fast. I can see it drop.

You probably have a leak. I sat and watched mine for a minute and it didn't change.

Well, the fuel pump and strainer from Fiero Store (bought with $100 Xmas gift certificate, hush) was sent 2nd day air this morning... I called them and ordered it, like, at 7am my time, 9am their time (or 10, I don't know this DST shit). I got the UPS tracking email and it turns out they are sending it NEXT day air instead! :love4:

Since it's all coming tomorrow, that works great since another Fiero dude I met on Old Europe wants to give me a tour of the Fresno ANG base tomorrow (or some time after, but I prefer tomorrow!). So I'm getting all ready in advance. ^-^

Step 1... jack up the car. Actually, step 1 was to get rid of as much fuel as I could, but that didn't work too well since the Fiero is apparently siphon-proof. Bastards.


The camera was tilted in that first picture, not the car. :thumbleft:

Yay for Garage PC! I can post and read without ever leaving the comfort of my car and greasy as hell hands. :thumbleft: