Gain extra benefits by becoming a Supporting Member Click here find out how!
Classic Performance Products Classic Parts
American Auto Wire Classic Industries
Chevs of the 40sDanchuk Catalog
Hellwig Products IncPerformance Rod & CustomEcklers AutoMotive
Nu-Relics Power Windows
Impala Bob's Bob's Chevy Trucks Bob's Chevelle Parts Bob's Classic Chevy

Username Post: Mostly a no start, or very rough idle.        (Topic#356856)
Posts: 36
Reg: 08-14-15
06-17-19 07:56 AM - Post#2768662    

Changed fuel filter, pump is good. Truck was running fine until it wasn't. It was running pretty good. I still have spark and am getting fuel. The engine will crank, but won't start most of the time. If it does start, it will idle very low and rough and eventually kill. I've seen this issue on youtube as a no spark thing, but I do have spark. My distributor and rotor are new. This is a 1990 c1500 TBI 383 build. Pulling the O2 sensor or disconnecting the computer results in no change. The IAC is brand new as well. Any tips for saving me some time on this? "Service Engine Soon" light was on, but I only got a code 12.

Silver Supporting Member
Posts: 73
Loc: California
Reg: 06-19-18
06-17-19 11:19 AM - Post#2768689    
    In response to johnboy1022

  • johnboy1022 Said:
Truck was running fine until it wasn't...
… My distributor and rotor are new...

Any connection between installing the new parts and the sudden idle issues? In a recent post someone inadvertently switched the #1 and #3 plug wire positions on the distributer cap.

Posts: 36
Reg: 08-14-15
06-17-19 01:11 PM - Post#2768698    
    In response to rittercon

None I could tell. It was low on gas, like really low. It kinda choked but started up and I took it to the gas station and filled up. After the fill up it choked a little more, but started up and ran fine until I got home. Then it started the rough idle. I decided a break was in order. A week later it is almost impossible to start, and if it does, I get the low idle death march. I'll double check the plugs when I get home to make sure. The only recent work that has been done was changing the valve cover gasket, oil, and filter. Took it for a spin after that though and it ran fine.

Valued Contributor
Posts: 4204
Age: 36
Loc: wv
Reg: 08-29-12
06-17-19 07:04 PM - Post#2768723    
    In response to johnboy1022

It will flash the code 12 three times before it goes to the first trouble code. It will flash that one three times before going to the next. When you get a 12 again you know you've got them all.

If you have good blue spark, check your fuel pressure. Just because you're getting some fuel doesn't mean you're getting enough.


'88 Chevy K3500, aluminum head roller cam 511in³ stroker 10.5:1 compression, 96 NV 4500, 94-98 grille, 305/70-16 (33x12) BF Goodrich KM2s, 91 cluster swap

Posts: 55

Age: 34
Loc: Upstate NY
Reg: 02-03-18
06-19-19 01:47 PM - Post#2768838    
    In response to johnboy1022

Just a thought have you checked the coolant temp sensor in the intake? Mine has had close to the same symptoms a few times and got worse the closer it got to operating temp and wound up being a bad sensor each time one was new and wound up being faulty from the start quick and cheap fix just a suggestion is all.

If it's to loud your to old

93 K1500 Z71 step side ext/cab 5.7 shorty headers and 3in true duals. 3in body lift and leveling kit.

89 K1500 4.3 rotted frame dubbed parts rig Sold

Posts: 36
Reg: 08-14-15
07-15-19 06:40 PM - Post#2770785    
    In response to Skribble93

I will take a look at that. I did have a small coolant leak shorty before this problem started and had to replace the heater core hoses. I took a short 1 minute video of the issue if you are interested.

Noisey Engine Idle

Edited by johnboy1022 on 07-15-19 06:42 PM. Reason for edit: No reason given.

Subject Matter Expert - Senior Member
Posts: 3816
Loc: Twin Cities, Minnesota, U...
Reg: 04-25-04
07-15-19 08:18 PM - Post#2770788    
    In response to johnboy1022

I agree with bowtie.
Test the fuel pressure with it running.
It could have a broken fuel pressure regulator spring.

The Youtube sounds like it is lacking fuel.

For those of you that are wondering why you are not getting replies to your thread:

Did you give the model, year, engine, fuel system type, and transmission information?

If your vehicle has been altered from stock, let us know about that too.

Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.088 seconds.   Total Queries: 16   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 05:24 PM