fiero with 2nd gen swapped 3.1l wont start

[mtownfiero]

About a week ago when i had enough of the 3.1l installed into my fiero that i figured id try starting it. The only things not done at this point where the block off for the egr on the exhaust manifold, the exhaust after the manifolds and i had forgotten to plug the o2 sensor wiring in.
Before really attemping to start it i unplugged the large connector to the coils and cranked it so that the motor could recirculate some oil to keep it from starting dry. I primed the fuel pump a bunch of times and had fuel pressure. When i went to actually start it, it would crank over fire keep cranking fire again then keep cranking. Like it had a miss or something?
The details on the 3.1l are that it is running on DIS, a fiero harness modified to use the 1227730 ecm, 88 style fiero timing cover and accessories, delted egr and evap and 3x00 exhaust manifolds. Those are the only things i can think of that are not stock to the motor. I didnt try start in open loop mode i think its called to get the timing set but im not sure if that would be a problem since its not starting at all. I have another ecm i could try but im just looking for some suggestions. Thanks, andrew

[FallenZ24]

There could be a few things that are causing a non-starting problem. Are you sure that the wiring is 100%? Maybe you did something wrong when doing the '7730/DIS swap. Did the engine run before installing in the Fiero?

Maybe you should talk with Darth on PFF about your problems. I know there were a few mistakes on his wiring "spreadsheet" that I had to correct myself. I didnt have any problem starting my 3100 on the first try when I did my swap. And that was with 30# injectors and no tuning.

-Joseph

[55trucker]

What ECM are you using?....when going to a DIS engine the general practice is to use the Cavalier ECM (DIS) and rewire the harness & reprogam the chip for use in the Fiero.

[mtownfiero]

There could be a few things that are causing a non-starting problem. Are you sure that the wiring is 100%? Maybe you did something wrong when doing the '7730/DIS swap. Did the engine run before installing in the Fiero?

Maybe you should talk with Darth on PFF about your problems. I know there were a few mistakes on his wiring "spreadsheet" that I had to correct myself. I didnt have any problem starting my 3100 on the first try when I did my swap. And that was with 30# injectors and no tuning.

-Joseph

Im pretty sure i follwed the 7730/dis thread very accurately and all the wiring should be correct. The motor was actually rebuilt, turboed and install in another fiero before mine but the previous owner had it running on the stock fiero distributor setup with the aluminum heads and the turbo. Since he had run some of the vaccum wiring wrong and delted things like the iac it ran lean or rich i cant remember but he didnt realize his error. However it was infact running just not well. I coverted it back to dis added all the correct sensors and did the connector wiring over.
It almost sounds like its not getting spark which im thinking might be the case since i the coils i have i bought used and they are aftermarket ones to begin with. Does this sound plausible and how would i check them?


As far as the ecm, both of the ones i have are cavalier ecm's and are 1227730's. I had a cavalier harness but adapting that to the fiero was much more work and unneccessary complication that adapting the fiero harness to the 3.1l and the cav ecm.

[55trucker]

Now I realize that this diagram is not specifically for the Cavalier....but the principle is the same. Hope this helps somewhat. Are you getting a tach signal (tach gauge moves) as the engine cranks? *Note paragraph #3

[mtownfiero]

Ok so today i put the exhaust in place temporarily since it needs to be finish weleded on one part, blocked on the egr on the exhaust changed the ecm to another i had added gas ah wal la it started! Only things now im worried about are that i only i had it going for like 30 seconds at a time because it was REALLY loud but it was running at 2.5k and the oil pressure was pegged out on the fiero gauge which i think goes to like 60. Would this be just because it was running cold or should i be checking some other things out.

[55trucker]

It lives!?........Our Fiero 2.8 pressure gauge pegs to full as well when the engine is cold (it's a fresh pump) and then settles down to about the center of the gauge when at running temp at idle.

[mtownfiero]

phew.. thanks i was hoping there wasnt something wrong because of it. If might be able to post a cell video if i figure out how to get it on you tube or something.

[x-thumpr-x]

Yeah, the Fiero pressure gauge tops out at 80 psi. When I'm driving around it's sit around 60 + psi and during idle it's around 40 psi. I ussed the same ECM for my 3400 swap but I used the Fiero harness and adapted it to the ECM. It runs out the correct location in the firewall, then ran the wires to where I needed them to go, after spliced in the new connectors for the 3400 sensors.

[mtownfiero]

Thats what i did to. The only sensors that had to be wired in on mine wire the two sensors on the throttle body i had to cut the fiero ones off the harness and match the wires up with the ones on the same pin # and color and the knock sensor and DIS stuff. Pretty easy overall.