I've been up, down, all around my Fiero trying to get it running. I apparently can't get it running, ha. I've changed a ton of parts in my quest to get this damn car going. Things I've done: Timing was off by 3 teeth, so reset the gears to 0. Changed out cam for a Melling MTC-5 w/ new lifter set Had bent pushrods, so swapped pushrods out for comp cams ones Installed comp cams 1.52 roller tip rockers Went through ignition: cap, rotor, ign. coil, pu coil, module all new, replaced plugs between module and coil, coil and hot/ tach. tested ign and pu coil resistance with meter and also ignition test light; all good New sensors: CTS, MAP, IAT, O2 New Starter Resoldered ECM grounds and made sure they were tight on the tranny bolt they mount to New fuel pump, filter, regulator, pintle injectors. Fuel pressure tested, goes to ~50 p.s.i. and slowly drains back down. Fuel pump comes on with key on. Deleted CSI replaced cracked front manifold with a good one New Dorman harmonic balance. Transferred the proper timing marks onto new one
Relocated battery up front w/ V8 Archie tray. Ran POS and NEG leads w/ 2/0 wire. Made ground straps w/ 2/0 wire and copper lugs from Batt to chassis and engine to chassis. One thing that has me concerned is if I crank on the starter a while, the starter starts dragging. Possible sign of a Voltage Drop?
After I did all this and got the engine back in, it was a little hard starting but ran for 5 minutes. I thought I had success because it ran great. I stepped out and revved the engine from the throttle body. As soon as I touched the throttle it died and I haven't been able to get it to crank since.
I'm wondering if it jumped time when I revved it? I pulled the cap today and checked between the rotor orientation and the 0 timing mark. I didn't get it exactly at 0, it was a little past. The rotor was just a little past the #1 point on the stator "star". So, I'm assuming timing is good. I still have the electronic timing set at 0 because I can't get the damn thing running long enough to balance 10 degrees adv between 1 & 4.
Since I've given the run down of what I've done so far, I'm curious if I have a bad ECM. I'm not getting any codes and I pulled the PROM to see if Code 52(I think?) came up and it did. I was careful to reseat it in the proper orientation. I checked all connections to ECM to see if I had corrosion issues or bad connections, seems fine. Will the ECM go bad and not throw any codes?
What do you fellas think?
One more thing, I just bought an OTC Compression Tester today and I just bought my wife a new laptop. I'm gonna take her old one over and use it for diagnostic work.
Disconnect the ECM at the Battery junction terminal. Wait a minute and re-connect. SES light on when you turn the key? Crank the starter and notice if the tach moves up to about 300.
Reset the ECM multiple times through my troubleshooting. While cranking the tach ratchets up all the way until it pegs out. SES light comes on with key on. In diagnostic mode flashes code 12. That's the thing, everything looks good. But it's not, obviously. Could the ecm be bad and not have any obvious symptoms?
[This message has been edited by bigdust80 (edited 05-24-2015).]
Yeah, on cranking the tach rolls around until it pegs out. On each revolution of the starter it'll bounce roughly 100 RPM on the tach until it hits 7000. As of now, I have the tach filter bypassed, if that makes a difference.
[This message has been edited by bigdust80 (edited 05-24-2015).]
My repair was better than it was. The grounds were cut and crappily butt spliced back together. I cut them back to good wire, soldered and then shrink tubed the splices. I then put the ring terminals securely back in place on the tranny bolt. I did a continuity test between the ecm case and the ground in the chassis by the ecm. Got a good strong tone. Do I need to do a continuity test from the grounds themselves where they plug into the harness to the chassis?
Don't think so, but was your car re-wired by a PO? Maybe some other things are not right. I would try to get the tach to show 200 - 300 rpm when cranking the starter, and go from there. That shows that the primary ignition is working.
Turning the crank clockwise stop at 10 deg btdc. Don't go backwards to get there because you want any slack in the timing chain to be on the correct side. Then as perfectly as you can alight the prongs and points inside the distributor. This will be close enough for starting the engine.
I would check for spark using an inline tester. This tells you if your spark plug is actually firing or not. It sounds like your primary is working since you are seeing something at the tach. Sounds like your tach is f'ed up btw.
I checked for spark w/ an inline tester already. Tested straight off the coil and #1 cylinder. Lit up like a Christmas tree. Gonna do the other plugs later but my assumption is spark is good. Right now I'm leaning towards a stretched timing chain that jumped time, poor compression(which I don't think is the case) or bad ECM.
The reason i'm thinking it jumped time is after I got the engine installed and hooked up. I got it to crank and run for a few minutes. It ran well. Then I goosed the throttle a little and it died and I couldn't get it to crank. Thing is, how much slack does it take for it to be too loose. I checked the chain when I had the engine apart and it didn't seem too loose.
I'm planning on pulling the plugs and rolling the engine over to 0 by hand to check my timing.
ECM's do go bad but it is a rare occurrence. If the found that the timing was off by three teeth and you replaced none of the drive parts; the chance that they slipped again are probably high. A new timing chain at the minimum may help but if the gears were unevenly worn they could be part of the problem as well. Could the crankshaft be walking?
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
If I've found that the chain slipped, I'm gonna replace with a double roller setup and just eliminate the whole chain stretch issue. I hope the crank's not walking. The engine is supposed to be a fresh rebuild. It's fresh from what I can tell when I went into the engine. The block was bored .25mm over. I didn't look at the bottom end, though. I think the block was rebuilt by a local shop and they may have cheaped out and reused the original timing set. Hopefully I don't have any crank issues.
Well, everyone, I got her running. Had slack in the timing chain. Changed out the timing set for a new cloyes one and it starts every time now. Thanks, everybody.
Well, everyone, I got her running. Had slack in the timing chain. Changed out the timing set for a new cloyes one and it starts every time now. Thanks, everybody.
Good job and glad to hear that the engine is running. When the timing chain goes loose, it is often accompanies by worn timing gears that can upset the timing. I suspect that's what happened.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Thanks for the report. I guess the rebuild was not quite fresh enough...
I think it was a halfhearted rebuild. I'm thinking the previous owner sent the block out got it punched and rebuilt it himself using the old parts. Hopefully it'll stay running until I can put a real engine in it.
