Running rough after sitting for 2 years.

434nova

Active Member
Joined
Sep 30, 2013
I drove the car yesterday for the first time in almost 2 years and I am noticing when I rev it up or put it in gear it has a stumble and bogg and is stuttering to go when I give it has. I was thinking maybe bad gas but when I look at the xfi I am getting some weird readings. I have a edash in the car and I am getting a iac reading of 110 at idle? It was as low as 65. But never got lower. I am also getting a map reading of 50 , isn't that only support to be reading boost? I have about 15 #s of vaccum at idle on my boost gauge. What is load on the edash it is also readding 50. The o2 reading are good and correction factor only moves just a little , maybe -.5 at most. I am wondering what it could be. Thanks for any help
 
I drove the car yesterday for the first time in almost 2 years and I am noticing when I rev it up or put it in gear it has a stumble and bogg and is stuttering to go when I give it has. I was thinking maybe bad gas but when I look at the xfi I am getting some weird readings. I have a edash in the car and I am getting a iac reading of 110 at idle? It was as low as 65. But never got lower. I am also getting a map reading of 50 , isn't that only support to be reading boost? I have about 15 #s of vaccum at idle on my boost gauge. What is load on the edash it is also readding 50. The o2 reading are good and correction factor only moves just a little , maybe -.5 at most. I am wondering what it could be. Thanks for any help
Bad gas can and will cause bad readings.get rid of the gas and the fuel filter and start over
 
Change gas and filter. Problem still there. What about my readings I'm getting any info on them.
 
I would remove your IAC sensor and clean it. Go through the reset process and lower your IAC to 20 or so at idle.
 
What is the reset procedure with a xfi. What does the iac do. Will it cause the car to both and stumbles and feel lazy? Thanks
 
Okay I did some driving and when I floor it car won't build boost past 5 psi. Motor is not reving clean. I have 2 wastegates on the crossover that I had pulled off when I did a transmission install. I only used rtv high temp when i reinstalled them. If I have a leak on the wastegates will it cause issues like i am having? Not reving clean and bogging and not building boost?
 
You may have some stuck or clogged injectors from sitting. If it pops through the air filter when you roll into it quick, that's a classic lean stumble.
 
It doesn't pop. It just boggs, won't rev clean , and won't build boost past 5#s. I'm think something is up with my wastegates. Can bad fuel foul spark plugs? Clogged injectors are also possible cause it did sit. When I first drove it it ran fine for 15 min. Then it started having the symptoms i am describing.
 
You have the ability to data log...Post a cold start, a warm start, and a driving log.
 
It doesn't pop. It just boggs, won't rev clean , and won't build boost past 5#s. I'm think something is up with my wastegates. Can bad fuel foul spark plugs? Clogged injectors are also possible cause it did sit. When I first drove it it ran fine for 15 min. Then it started having the symptoms i am describing.
Yes old gas could foul plugs.
 
You have the ability to data log...Post a cold start, a warm start, and a driving log.


Honestly I'm not sure how to record a data log. I do have my laptop hooked up to the xfi now.

Any thoughts on maybe a wastegates issue?

I'm gonna pull the plugs and see how those look like.
 
How much vacuum did you have before it sat? If you take the turbo out of the equation how's it run? You don't want to run boost if it's not able to rev clean anyway.
 
Pull spark plug wires one at a time. The one that does not change the idle will point to a cylinder at least. I broke a valve spring on another car and it wouldn't rev.
 
Here are the plugs I pulled out. They are all wet.
Plugs are 3933. I believe they are to 20170917_192653.jpg cold for street driving.

20170917_192711.jpg 20170917_192702.jpg
 
How much vacuum did you have before it sat? If you take the turbo out of the equation how's it run? You don't want to run boost if it's not able to rev clean anyway.
I always had around 15#s of vaccum at idle.
 
It'll never run right with fouled plugs. Try some NGK 7773 (NGK UR6). Gap @ .028. These are tried and true plugs. Rockauto.com has the best deal.
 
Change plugs to autolite 104 and car is running like a raped ape again. Wow I'm surprised how much fouled plugs make difference. Iac was also around 10. Car is back to normal.
 
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