any ideas? i have replaced the map, maf, iac, and the upper o2(fiero doesn't use the after cat).
any ideas? i have replaced the map, maf, iac, and the upper o2(fiero doesn't use the after cat).
86 Fiero Convertible 3800sc/4T65E HD(2002)
Need to attach your current tune. Looks like unmetered air getting in by the bucket load and car is pulling 33% fuel and is still pig rich. Try a can of brake cleans between the maf and lower intake and see if you have a leak there somewhere. Next I would be looking for an exhaust leak, cracked manifold, or cracked weld at the O2 bung.
2000 Trans Am WS6
i did recently find a large leak from the purge solenoid and have that repaired as well as a new map so i will have to get a new log but it still looked rich even after i fixed the leak at the throttlebody. The tune is basically stock with vats,egr,rear o2 removed.
86 Fiero Convertible 3800sc/4T65E HD(2002)
Set EGR Enable to highest temp possible, 284* in your case. Get a new scan up when you can. Lets see if its just needs tuning now and not still a mechanical issue. 0 out the add vs rpm table and also 0 out the add vs tps table. Its much easier to just use the MAF on its own. Get a scan AFTER those changes and post it up.
2000 Trans Am WS6
I think I got the settings correct. I also replaced the upper intake gasket as I soaked the motor in carb cleaner and found a leak so now that seems to be sealed sealed. I have two logs , the first ones short as it fired up and then started surging till it died. I started it up again and all was fine so thats a log up to temp just idling in the garage. I did rev it a couple times. Towards the end after I revved it, it started surging which is what it does when it gets warm.
86 Fiero Convertible 3800sc/4T65E HD(2002)
Your not logging MAF Hz anymore it seems, need that one added to your config file and try it again. Your tune is pretty much stock, there still has to be air getting in somewhere. Trims that far out still screams leak to me
Last edited by MMGT1; 11-11-2013 at 06:28 PM.
2000 Trans Am WS6
I added it now and will have to get a new log. What is the need for the maf in Hz? I thought I got all the leaks, I pressurized the system and it slowly bled not fast like before. I was thinking it was bleeding from the purge solenoid off the throttle body not sure where else it possibly be leaking from. Would even a small leak cause problems?Originally Posted by MMGT1
EDIT: I also forgot to add that I had a vacuum guage hooked up at the same time and it read 20 at idle.
Last edited by tweeder; 11-11-2013 at 08:29 PM.
86 Fiero Convertible 3800sc/4T65E HD(2002)
MAF is calculated in Frequency or Hz vs Air Flow. In this swap, did you utilize the factory manifolds on the engine? Is the #1 O2 sensor in its original location is what I'm getting at here.
And yes, a small leak after the MAF anywhere is bad. Have you checked the PCV system in that thing? The plastic retainer that holds the PCV in place in those is notorious for cracking or being damaged when a PCV is replaced. A lot of guys break those when they try to replace them
I have a nasty gut feeling that you are going to be replacing your intake manifold on this one, again very common on 3800's. Dorman has a replacement available now for a pretty good price if you end up needing one.
Last edited by MMGT1; 11-12-2013 at 09:10 PM.
2000 Trans Am WS6
Yes all is factory, manifold and front o2. I just replaced the upper intake gasket as I did test and it leaked. There is no PVC. With the vacuum reading 20 steady, that tells me there's no leak. But on a pressure test it did bleed slowly but couldn't find it, I will have to make a smoke test and see what that brings up. This one is supercharged by the way.
86 Fiero Convertible 3800sc/4T65E HD(2002)
The supercharger has the PCV valve inside it, its that one black cap with 2 bolts on it.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
Lol, now that's a blonde moment right there. I did see that and I thought it was a block off plate where the PVC used to go. I will have to recheck but I don't recall that leaking from there but I can't remember if I did spray it or not.
86 Fiero Convertible 3800sc/4T65E HD(2002)
Not sure if this is it but I sprayed a soapy solution in the injector holes and sure enough injector number three is bubblin, so I have a set of o rings on order.
86 Fiero Convertible 3800sc/4T65E HD(2002)
Got the new o rings in and now a new problem, I swear I get a new problem every time in fix something else. Now it won't start, I checked and I am getting fuel and spark but it backfires really powerful and loud. So powerful that it blows the rubber exhaust tubing right off the pipes.
86 Fiero Convertible 3800sc/4T65E HD(2002)
Did you find the problem? Get a scan of it doing this?
2000 Trans Am WS6
No time yet, I could do a scan of me cranking it over and what not, I'm hoping to look at it tomorrow and see if there's something obvious like a wire pulled out or something?
86 Fiero Convertible 3800sc/4T65E HD(2002)
Don't know whats going on but she fired up, it took a few trys with it backfiring and dying but i got a log. I though I got the leaks figured out by sealing the upper intake but towards the end of the log I sprayed carb cleaner and it stumbled. I don't think I could put more silicone in there than what I did.
86 Fiero Convertible 3800sc/4T65E HD(2002)
Like I said in the beginning, those intake manifolds do go. Saw at least one every couple of months getting replaced when I worked for a GM dealer here in Ontario. We always kept one or two in stock, this will give you an idea as to how common it has become to replace them. I think you need a trip to a reputable mechanic familiar with the issue, or a trip to the dealer and let them diag the problem... sorry if this is bad news man....
2000 Trans Am WS6
What part goes, the supercharger gets warped or the lower intake manifold? I did put a good 1/4" bead all the way around. The weird thing is it stumbles with carb cleaner but when I pressurize the intake and spray the same corner, I can't get no bubbles.
86 Fiero Convertible 3800sc/4T65E HD(2002)
The manifold, but I would have it checked by the pros at this point so you are not throwing away money
2000 Trans Am WS6
The problem is I'm from a small town way in the north and we ain't got any reputable people to consult with which is why I turn to the forums.
86 Fiero Convertible 3800sc/4T65E HD(2002)
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