Exhaust leak is before O2’s. Only code is for the MAF (unplugged). I’ll take a look into doing both of those. What’s the best way to get vacuum readings while driving?
Engine Foxbody idle/throttle issues
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Vacuum tree on the firewall I believe has a port that's not used, if not use the one marked A/C
Oh, and clean up those disgusting, grimey, oily connections
Oh, and clean up those disgusting, grimey, oily connections
If you have an exhaust leak between the exhaust header flange and the H-Pipe flange then it will cause inconsistent readings with the O2's. Trying to locate an intake leak with the exhaust leak up that close to the motor is pretty hard so focus on the exhaust leak. You can spray a little carb cleaner around where you think the intake leak is and if the rpm's jump up then you have a leak.
You have to set the timing or you are just throwing another variable at the EEC. It only has 12.5% +/- correction total so everything that gets out of whack starts chewing up that correction ability.
Have you cleaned the MAF sensor?
You have to set the timing or you are just throwing another variable at the EEC. It only has 12.5% +/- correction total so everything that gets out of whack starts chewing up that correction ability.
Have you cleaned the MAF sensor?
I’ve been hearing the intake leak, or possible TB whistle well before I got the exhaust leaks. I’ll get them tightened up though so it’s one less problem. Getting the hardware tight on these wider chamber headers is a huge pain. I got the timing set to somewhere between 10-14°. Sorry that isn’t more accurate, the balancer goes from 10° to 20° lol. It runs much better than it did before I pulled the engine apart. It didn’t idle hardly at all before, but now it does. The falling on its own face under any throttle with the maf plugged in is still there though. I’ve also cleaned the maf sensor many times, aswell as exchanged it with another 24lb BBK sensor. A buddy of mine just gave me an OEM maf so I’m going to throw that in and see what happens. I’ll also get those vacuum readings once I fix the valve cover leaks.
It’s an orielleys “performance” balancer. It seems like it’s doing alright, timing marks are steady and very clear. I just swapped in a stock MAF just to see. No change. Maybe I do need a better MAF though. Don’t really wanna spend $300 to find out it doesn’t do anything though
So, I got some more parts from a buddy. MSD coil, aswell as an oem MAF and MAP. Installed all 3, no noticeable difference.
I did run codes, and according to the reader for the KOEO I have a 31O, 81O, and an 82O. I deleted my EGR, smog, and all TAB solenoids and such in the passenger area. KOER test I have a cylinder 4 misfire, 12R, and 21R. I did this test with all those parts installed. Not sure if I’ve mentioned this before, but the car is super rich.
I did run codes, and according to the reader for the KOEO I have a 31O, 81O, and an 82O. I deleted my EGR, smog, and all TAB solenoids and such in the passenger area. KOER test I have a cylinder 4 misfire, 12R, and 21R. I did this test with all those parts installed. Not sure if I’ve mentioned this before, but the car is super rich.
Also, I have replaced the coolant temp sensor, and harness a while ago. Aswell as the coolant reservoir sensor. Car still shows low coolant at all times. Temp seems accurate though.
I fully intend on going through the whole checklist to narrow things down before spending a boatload on parts, just gotta wait for an empty day. As of now, here are my personal thoughts in no particular order.
1. Computer
2. Oem fuel pump not enough for setup
3. Maf truly is a bad brand
4. Distributor/TFI from orielleys is bad (I’ve had 1-2 go bad before)
5. To much air from 70mm throttle body
6. Intake not seating on heads correctly if the heads were machined prior to ownership (the engine looked to have been a fresh rebuild when I pulled it)
There were some other things that I don’t remember, but those are just my ideas. I don’t think any of those really correlate with my cyl 4 misfire though.
1. Computer
2. Oem fuel pump not enough for setup
3. Maf truly is a bad brand
4. Distributor/TFI from orielleys is bad (I’ve had 1-2 go bad before)
5. To much air from 70mm throttle body
6. Intake not seating on heads correctly if the heads were machined prior to ownership (the engine looked to have been a fresh rebuild when I pulled it)
There were some other things that I don’t remember, but those are just my ideas. I don’t think any of those really correlate with my cyl 4 misfire though.
I am guessing stock is 205? Your computer will think your car is too cold and will enrichen your mixture until it reaches what is the correct temperature in its program..... Had this happen in a ford V6 minivan years ago.... Friend did this and his mileage went to 10mpg and it never ran right until we put the " hotter correct temp stat back in it......
You are partially right, I didn’t realize that. Stock thermostat opens at 195, and I do believe I went to a 180. However, these problems are present no matter what temp the engine is at. Also, I believe everyone does the swap to a 180 so I can’t imagine it’s causing any issues especially since it isn’t a drastic change. Just helps it run a little cooler.
I understand wanting to run a car cooler and maybe with a lesser pressure cap too....
Just telling you what my experience was....
When we reinstalled the correct hotter thermostat the car ran like new with 20+ mpg again....
I did it, a few members here have done it too, most are attempts to resolve a 'running hot' condition, real or perceived, I did it because I'm old and wrote must of 'the old mechanics tails'. In the real world of EFI and Computer Controls (although our stuff is mostly dated now) they are 'programmed to do things at certain temps, the 180* thermostat just allows the coolant to flow more sooner, the engine temp is gonna be what it is which most times should be 190* to 205*.
The small temp range on the stock gauge give some owners panic attacks, I always say the stock gauge is just a guess.
I’ll keep it in for now, can’t imagine it’s causing much issue. It’s super hot outside, so I’ll wait for the weekend to run more tests, but I pulled the wire off cyl. 4 while running and I think I noticed a slight change, but maybe I’m crazy. I know if it was running properly it would be a pretty substantial change, so there’s something going on over there. I’ll check spark and fuel this weekend to see if there’s an issue there.
Sorry, actually I know spark is good because I jolted the hell out of myself doing it lol. So that tells me there’s a different issue, unless it’s not enough spark? I’m unsure
The computer told you there is a problem with #4 cylinder,check plug, wire and that tower on the cap, if you can do a compression test on that cylinder.
Have you done the 'surging idle checklist '?
Have you done the 'surging idle checklist '?
In the past, in pieces. Fully intend on doing it start to finish when I get a chance. Just haven’t had a moment to really sit down with the car. I plan on inspecting the cylinder this weekend and hopefully starting on the checklist.
Check the spark plug for cracks. Get your hands dirty and rub the body of the spark plug. This will show any cracking which could cause the issue.
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