but for some reason, the car doesn’t fire properly. the idle is low, but erratic, and even flooring the gas pedal has almost no reaction on the throttle. the car occasionally pops and backfires. please help, as I am losing my mind.
EDIT: I just drove the car from my shop to my house (I crept with hazard lights on), and it hardly had any power, sounded like hell, and stalled often during stops. A little bit of smoke the entire drive, but I could NOT distinguish the color.
Yes, they are in the right firing order… BUT I did notice that the part of the distributor that plugs into the cam was backwards from the old distributor (which was 3 years old AT LEAST), so I switched it around 180 degrees, and worked just a tiny bit better.
Yes, 100%. I timed/checked it 10 actual times, as well as having my coworkers double check it (I work as a helper in a shop, and we’re ALL stumped.)
It’s hard to help over the internet, but I’m leaning toward something with the distributor.
Was the distributor replaced after you found it was misfiring? I’ve heard of them installed backwards (even though it seems impossible)
Did you rewire for the obd2 distributor while doing the timing job?
[QUOTE=386;2309621]It’s hard to help over the internet, but I’m leaning toward something with the distributor.
Was the distributor replaced after you found it was misfiring? I’ve heard of them installed backwards (even though it seems impossible)
Did you rewire for the obd2 distributor while doing the timing job?[/QUOTE]
We’ve had the car for about 3 years now, and the previous owners we’re the ones to rewire the distributor harness, but it has been working fine up until now. We replaced it with a brand new distributor , but we had to flip around the tiny little notch that fastens into the end of the cam . Yes we replaced it after the issue came about
What was the reason for the timing job?
Are there any codes?
Try these things.
Check that each cylinder is getting spark, when you do this, also make sure that each cylinder is getting fuel, by taking out plug after spark test and see if their is fuel in the cylinder or on the plug, you can smell it.
Reset the ECU by removing the battery cables and touching them together for about 15 seconds. It may run better temporarily, telling you the long term fuel trim is being overcorrected. That will more than likely indicate an intake or header leak, affecting the map and/or o2 readings past the ecus ability to fix.
Check for vacuum leaks with brake cleaner or something of the like.
Check for exhaust leaks upstream of the O2 sensor.
If you find nothing wrong, or nothing changes, I would try a leak down test just to be certain.
After that, I’d have to say it’s either two faulty distributors, or incorrect timing.
(If anyone has anything to add, or correct me on, don’t hesitate)
Throwing this out there. A while back, My 91 started misfiring badly on the freeway all of a sudden. I spent 3 days trying to figure it out. I even blew out the cat. Turns out that the distributor rotor screw came undone and the rotor did not spin in sync with the shaft. I’d check it if you haven’t.
hows that obd2 cut & splice job look? Is it hacked up or what ? That was my problem cuz the pins in the connector wasnt making good contact at the distributor & i almost took a shot gun to it lookin for the problem
you’ll want to start by categorizing the issue. first, figure out if the problem is affecting a single cylinder, or if all cylinders are affected equally. run a power balance. disconnect one injector at a time. if condition doesn’t change with a single cylinder disabled, you’ve found the problem area. then you’d just need to determine whther it were an ignition or fuel issue (compression test has already been performed, so we can cancel out that possibility). use an HEI tester to check for spark at that cylinder. simply checking for spark in open atmosphere is not enough. cylinder pressure places a resistance on ignition comparable to a spark gap of about 3", so an HEI tester is the only way to accurately check for adequate ignition. they are extremely cheap anyways. and a good tool to have for future diagnostic.
if you have good ignition at the problem cylinder, check for injector pulse at that cylinder using a noid light (194 bulb works well). if no pulse, check for it at the ecm. if no pulse there, driver is blown and the ecm will need to be replaced.
you see what we’re doing? we’re categorizing and zeroing in on the problem. there are only a certain number of possibilities which could affect a single cylinder. just like there are only a certain number of possibilities to affect all cylinders equally. which are:
-vacuum leaks
-fuel supply
-timing/ignition (before the plug wires)
-ecm input(s)
-ecm
they all have there own simple tests to further pinpoint the problem. the fact that this started after engine work would make it most likely something you touched/moved, or forgot to reinstall or was reinstalled incorrectly. vacuum leaks would be the best place to start. to determine if unmetered air is entering, remove the air cleaner boot. start the engine. cover the throttle bore completely using the palm of your hand. if the engine does not stall right away, there is outside air entering.you can further pinpoint the source, as mentioned, by spraying carb cleaner or brake clean around suspect areas.
try some of those quick checks, in the order posted, and get back to us. if you don’t find the culprit through them, we can dig deeper until we do