C5 crank no start
Thread Starter
7th Gear
Joined: Dec 2024
Posts: 7
Likes: 0
C5 crank no start
I have a 98 C5 crank no start situation, I don’t get any codes other than P1285 & P1286 car will crank and crank but just won’t fire car is bone stock and this problem only started after it rained. I’ve so far replaced the cam, crank, map, maf, all 8 injectors, all 8 coil packs, plugs, plug wires, alternator, tps, and I’ve even cleaned all 8 ground points now I’m just stumped as to why it won’t run each time I can hear the fuel pump prime and most of the time the car sputters like it wants to start but just doesn’t and at times it backfires quite loudly and just goes back to cranking
Last edited by LSX_JJAY; Dec 15, 2024 at 06:26 PM.
Intermediate
Joined: Nov 2024
Posts: 34
Likes: 7
I have a 98 C5 crank no start situation, I don’t get any codes other than P1285 & P1286 car will crank and crank but just won’t fire car is bone stock and this problem only started after it rained. I’ve so far replaced the cam, crank, map, maf, all 8 injectors, all 8 coil packs, plugs, plug wires, alternator, and I’ve even cleaned all 8 ground points now I’m just stumped as to why it won’t run each time I can hear the fuel pump prime and most of the time the car sputters like it wants to start but just doesn’t
Tech Contributor
Joined: Jan 2007
Posts: 19,396
Likes: 1,137
From: Dyer, IN
Melting Slicks
Joined: Sep 2008
Posts: 3,131
Likes: 799
From: Espanola New Mexico
Why would the OP replace all those parts listed, without taking it to a electrical automotive shop or having somebody with a scan tool look at all the signals like injector pulses, coil pack pulses. I agree with lucky on this one, something doesn't seem right, and we will probably not hear anything back from the OP.
Pro
Joined: Jun 2022
Posts: 691
Likes: 317
From: NW OH
Why would the OP replace all those parts listed, without taking it to a electrical automotive shop or having somebody with a scan tool look at all the signals like injector pulses, coil pack pulses. I agree with lucky on this one, something doesn't seem right, and we will probably not hear anything back from the OP.
Le Mans Master
Joined: Jul 2010
Posts: 6,002
Likes: 722
I have a 98 C5 crank no start situation, I don’t get any codes other than P1285 & P1286 car will crank and crank but just won’t fire car is bone stock and this problem only started after it rained. I’ve so far replaced the cam, crank, map, maf, all 8 injectors, all 8 coil packs, plugs, plug wires, alternator, tps, and I’ve even cleaned all 8 ground points now I’m just stumped as to why it won’t run each time I can hear the fuel pump prime and most of the time the car sputters like it wants to start but just doesn’t and at times it backfires quite loudly and just goes back to cranking
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Thread Starter
7th Gear
Joined: Dec 2024
Posts: 7
Likes: 0
Why would the OP replace all those parts listed, without taking it to a electrical automotive shop or having somebody with a scan tool look at all the signals like injector pulses, coil pack pulses. I agree with lucky on this one, something doesn't seem right, and we will probably not hear anything back from the OP.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,498
Likes: 3,999
From: Cape Coral, Florida
Did you actually check for spark and if you know how to check injector pulse do that…may be best to let a diagnostic shop fix this before you waste any more money on parts.
Thread Starter
7th Gear
Joined: Dec 2024
Posts: 7
Likes: 0
I replaced coils, plugs, plug wires and injectors way before any of the problems happened as the car had obviously sat for months maybe even years and it was running good after it all until it just didn’t wanna start I have used a noid light and can verify the injectors are firing and I can actually hear them firing too and I would assume I’m getting some sort of spark even if it’s weak if the car backfires every now and then but will verify tomorrow
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,498
Likes: 3,999
From: Cape Coral, Florida
You can’t ASSUME you’re getting spark…pull the plug wire off the coil pack and leave some gap and see if you have spark…any time you change a part you do a “repair verification”…don’t assume the part is good…a crank no start should take about an hour or less to diagnose…did you check fuel pressure ??…before you change a part you check its wiring is good…you said you verified the MAP and MAF sensor…HOW did you verify both ??
Thread Starter
7th Gear
Joined: Dec 2024
Posts: 7
Likes: 0
You can’t ASSUME you’re getting spark…pull the plug wire off the coil pack and leave some gap and see if you have spark…any time you change a part you do a “repair verification”…don’t assume the part is good…a crank no start should take about an hour or less to diagnose…did you check fuel pressure ??…before you change a part you check its wiring is good…you said you verified the MAP and MAF sensor…HOW did you verify both ??
Instructor
Joined: Sep 2012
Posts: 156
Likes: 9
From: Sprint Car Territory
Maybe try to check the contacts in the ignition switch. You will find how to on how to do this on Youtube. If the contacts are balck, replace the ignition switch. I had similar issues but they were intermittent. I hope this helps