Ok... very strange. I jacked up the 88 2.5L to fix something. I ran the car in the air and it ran just like normal. I lower the car and start it and it starts and dies. I thought.... well, I am low on fuel, nope, I added more (5 gal) and nothing changes. I see fuel spray when it cranks but then the fuel stops and the car stalls. I tried added some fuel down the TBI and it seems to run longer.

I checked the fuel pressure and it is about 9.5psi (based on the vac. guage I have). I also ran the fuel pump through terminal G and nothing changes.

So, what should I check next. What causes the injector to stop firing? I can't find my extra ignition module/coil pack to see if that is causing a problem, but I can't locate it.

I just need to fix it so I can sell it. It runs good, but this is strange.

suggestions?

Yank some wires/grounds in engine area is my guess.
Jack it up again and see if it work.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 04-13-2011).]

had to be something related to the injector. I removed it, ran the pump, put the injector back. Nothing. I grounded the blue wire and cranked. Nothing. It must have flooded the engine as I took off the ground and floored it to clear the gas out and it started after some coughing. It has been running and restarting ever sense. I wonder if I had something stuck in the injector (varish)?

Anyway, I am putting it back together and I will be selling it.

Anyone else have some theories? BTW, I was using an 86 manual and the color or location of the ecm wires is different, so I couldn't check continuity. Anyone have the schematics for the 88 ECM connections?

[This message has been edited by jaskispyder (edited 04-13-2011).]

problem came back... it will stall when running, Time to part out. Watch in the mall for parts.

Unless someone has an idea of what to check next. The injector just quits firing, but it will fire when cranking. playing with the ecm wires doesn't change anything. Or playing with the harness, no change. Could it be a bad ECM?

[This message has been edited by jaskispyder (edited 04-14-2011).]

Injector will not fire when ground using blue wire?
Injector should had firing right away when key is on. "Signal" for ECM to fire injector ground blue wire.

Injector is bad. Unlikely but can happen.
Injector doesn't have good connection or bad wiring.
Fuse is blow or get crappy connection. But same fuse runs ECM so ECM get a good check engine light likely fuse is good.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

Interesting, this worked. I was able to turn on the fuel pump and jump the injector and it sprayed nicely. Now last time I tried this, the injector didn't fire.

Which connector and number is the blue (and red) wire at the ECM connection? My 86 manual doesn't seem to be correct. I can check for continuity. I suspect a sticking injector or a bad ecm (maybe gets hot and stops the connection)? At least I can test this now.

Thanks! Plus for you (if I didn't give you one already)

[This message has been edited by jaskispyder (edited 04-14-2011).]

Here's a pic from the 88 shop manual:



Fix the car so I'm not tempted to buy it. I told myself no more four cylinder Fieros...

And download 88 SM... http://www.fieronews.net/fusion/downloads.php

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

Thanks guys, I will check the continuity tonight, but I have a feeling it is the injector or ecm, as why would it fire then die? There is a question... is there a difference when it cranks and runs vs running.... does the ECM do anything different? I guess I could have a problem where the ECM heats up and then causes this problem.

More troubleshooting coming tonight.

Key on when you ground the blue wire - the injector should click.

Key on, fuel pump wired on, the injector should spray when the blue wire is grounded. If the injector isn't spraying then either you don't have fuel pressure, you don't have +12v on the red wire, or you have a bad injector.

Have a fire extinisher handy whenever you work on the injector like this. Also not that you can have a flare up if you make a spark at the injector and start gas in the manifold on fire.

[This message has been edited by phonedawgz (edited 04-15-2011).]

we have seen this before did you have the cap off the distributor? if so you may have pinched one of the wires it will kill the injector and the spark.
and depending on how bad it was pinched it will work sometimes but not otners.
D.

88 use DIS. No cap....

quote Originally posted by theogre: 88 use DIS. No cap....

Oops! did not see the year, my bad.

When i jump the injector sometimes it sticks open now. I wonder if the injector is bad after all.

If the injector sticks open it is bad. It snaps open and closed every rotation of the crank. How long it is open is determined by the ECM speed of the crank, the temperature of the engine and the vacuum of the intake. There is more than enough time for the injector to snap open and closed during the rotation of the crank when the engine is rotating at 6000 rpm and for it to give the intake a full shot of fuel. If it sticks open even for a short while the engine WILL flood out and stall.

[This message has been edited by phonedawgz (edited 04-16-2011).]

I am jumping the injector, so I am making the injector do something it shouldn't normally do... but sticking shouldn't happen anyway, correct?

[This message has been edited by jaskispyder (edited 04-16-2011).]

What you are doing is what the ECM does multiple times a second. Unless you are keeping it energized for long times it is exactly what the ECM does. So yeah if it's sticking that is your problem. Check with the MALL section and buy one cheap.

New injectors are about $40 on ebay, and there's a few junkyards in the state that have an entire TBI, might call them and see how much + shipping



What about a clogged fuel filter? Do you have a fuel pressure gauge? Some auto parts stores lend them out for a deposit, not sure if any in Da Soo would, though.

http://cgi.ebay.com/ebaymot...fPartsQ5fAccessories

Thanks, but I would rather not spend even $50 (plus shipping)..... I am at the point where i can part it out and make the same amount or even more, so the more I put into it, the less I make on selling it.

As for junkyards, I can check on that, but I doubt they would be less than $20 shipped (which is about what I am willing to spend on this car at this point).

Fixed with replacement injector!

Another Fiero saved from oblivion.....