I recently just replaced the distributor on my 84 Duke with a reman AC Delco unit, which came with a new ICM already installed.
I took out the old one and put in the new one, wired up and everything. I put cylinder one (the one on the side of the crank pulley) at the top of it's travel and attempted to keep the distributor and rotor as close as it was before as possible. Upon doing this... it did not start, and just kept cranking. After this, I tried turning the distributor slowly in either direction while cranking, with the same result. After this, I repeated this again with cylinder one at the top... same result. Once again with removing the three other plugs so I could feel the compression to make sure it was on the compression stroke... with the same result.
I have spark (tested by wire to the frame) and I have fuel (can smell in the throttle body opening), and I have tried rotating the distributor (taking it out and reinstalling) 180 degrees, this hasn't worked either. This is so bizarre, the fuses are intact and I have fuel and spark, but can't feel or hear a single ignition from the engine while cranking.
Sounds like the timing could be off. Was the distributor installed with the rotor in the right position? Is the rotor moving as the engine turns over? Are the spark plug wires in the right position on the distributor cap? Remove the distributor and the no 1 spark plug. Put your thumb over the spark plug hole, have an assistant crank the engine in short bursts until you can feel pressure escaping from the spark plug hole. Now crank until the balancer timing mark lines up with the scale at the right setting. Replace the distributor so the distributor rotor sits at or just a tiny bit after the no one wire setting. Now jump the two pins on the ALDL connector, replace the plug and wire, start the car and use a timing light to achieve a precise timing setting. A remote starter switch works best for this procedure.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, 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 "
[This message has been edited by Dennis LaGrua (edited 05-15-2022).]
The ICM could be bad right out of the box. It has happened before. As you crank the starter, watch the tach for sight movement up to 400 rpm or so. If it does not move, the primary ignition is not working. swap your old ICM into the new distributor and try again. ...
Sounds like the timing could be off. Was the distributor installed with the rotor in the right position? Is the rotor moving as the engine turns over? Are the spark plug wires in the right position on the distributor cap? Remove the distributor and the no 1 spark plug. Put your thumb over the spark plug hole, have an assistant crank the engine in short bursts until you can feel pressure escaping from the spark plug hole. Now crank until the balancer timing mark lines up with the scale at the right setting. Replace the distributor so the distributor rotor sits at or just a tiny bit after the no one wire setting. Now jump the two pins on the ALDL connector, replace the plug and wire, start the car and use a timing light to achieve a precise timing setting. A remote starter switch works best for this procedure.
Yes, I made sure to have cylinder one at the top with the timing mark on the pulley and block lined up, and there is spark. The wires are in the right position as they are the same position in the cap as they were installed before, when it ran.
That is exactly the procedure I did, pressure coming out of the hole and the timing mark lined up, with the rotor facing right where the number one wire is. Pins jumped as well and everything hooked up- It still won't start. There is some ignition going on, but it won't catch and run. Starting fluid results in backfire.
The ICM could be bad right out of the box. It has happened before. As you crank the starter, watch the tach for sight movement up to 400 rpm or so. If it does not move, the primary ignition is not working. swap your old ICM into the new distributor and try again. ...
Thank you for the tip, but the tach does move up to about 400 when cranking, so hopefully that's all good.
Was the distributor specifically for the 84 Fiero 2.5? The ignition system of the 84 is different from 85 & 86.
How hot is the spark you saw when grounding the plug to the block?
Do you have an adjustable inline spark checker?
Yes, I checked and the distributors have the exact same structure and wiring. The spark seemed pretty strong, bright enough to see easily in daytime. I do not have a spark checker, hence the redneck method, lol. Can get one if it would help in diagnosis, but the timing light lights up when the number one plug gets spark.
At this point I would have to believe the distributor is still way out of position. It sounds like you pulled it out and replaced it a few times. There is only one correct position. Use the method outlined here to place it in properly. Sometimes if the distributor is off by even one tooth the engine will not start and run.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, 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 "
No ideas beyond what has already been suggested ,but I will offer that the distributor has to be very close or it will not start. Just a few degrees off and you'll have trouble. But it is odd, that yours is not even trying to start....like no back fire or anything??
Sounds like you are 180° off on the timing. Why not pull the valve cover and make sure both valves on number one cylinder are closed when the piston is at TDC? Then align the distributor with number 1 plug wire on the distributor cap. At least then you'll know timing is reght.
No ideas beyond what has already been suggested ,but I will offer that the distributor has to be very close or it will not start. Just a few degrees off and you'll have trouble. But it is odd, that yours is not even trying to start....like no back fire or anything??
Yeah it's firing but not catching at all, like not in sync enough to lead to an increase in rpm past the starter's 400 rpm. It'll backfire immediately if I put some gas or starting fluid in it.
One more suggestion. Use the timing light on no 1 cylinder wire. Crank the engine, Aim the timing light at the degree scale just over the harmonic balancer and see if the timing mark on the balancer lines up with the scale. The normal base timing is 8 degrees BTDC but it can be increased to 10* with premium gasoline. The timing light will also confirm if the cylinder is firing.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, 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 "
