Are you absolutely sure you have the correct size injectors? Also may not hurt to take a degree wheel to the cam and make sure it's degreed up correctly.
Extremely rich and rough idle
- Thread starter AfricanSnowOwl
- Start date
I’m not absolutely certain on the injector size. They are the OEM Bosch 5.0 orange explorer injectors. Those are 19lb right?
I am certain that the engine has never been opened up before. Does a cam just become undegreed? There’s no valve train noise and the timing doesn’t move at all with the spout unplugged, does move as it should with it in.
I am certain that the engine has never been opened up before. Does a cam just become undegreed? There’s no valve train noise and the timing doesn’t move at all with the spout unplugged, does move as it should with it in.
Those are 19#. Cam's don;'t become undegreed. There are mechanically linked to the crank via the chain. Even if the chain becomes very sloppy, its not enough to change the timing more than a couple degrees. Your wiring coule be improved, but is likely not the cause of the rich issues.
The extra wire coming off the neg terminal should also connect to the ECU ground on the fender. It connects via a ting terminal that has two leads. One lead it to the neg battery and the other goes to the black connector that can disconnect from the body harness.
Here's how it should connect
The extra wire coming off the neg terminal should also connect to the ECU ground on the fender. It connects via a ting terminal that has two leads. One lead it to the neg battery and the other goes to the black connector that can disconnect from the body harness.
Here's how it should connect
From reading pinpoint tests.
Questions
Have you checked vacuum with guage?
Does car have a map sensor?
Questions
Have you checked vacuum with guage?
Does car have a map sensor?
Yes, the vacuum reading at idle is 14-16". On the low side. Everything I read said low vac means timing is off or a leak, but I am 100% sure there is not a leak. I tried adjusting timing with the vac gauge hooked up. The car seemed to like advanced timing of around 14-15 degrees the best.
The car does have a map sensor. I tried changing it out with a different one and it made no difference. As far as testing the map sensor all I really did was verify the 5v ref wire had the 5v. Is there a better test to try with the map sensor?
The car does have a map sensor. I tried changing it out with a different one and it made no difference. As far as testing the map sensor all I really did was verify the 5v ref wire had the 5v. Is there a better test to try with the map sensor?
Clogged exhaust is also a cause of low vacuum
See you have off road mid.
Who’s muffler? Open exhaust and test
Another stupid part
Balancer on crank
Does tdc line up to pointer
A friend just had this issue but a no start. Balancer slipped and caused timing issues
Pinpoint test say map may cause 42/92 without getting 22 code
Says test map to see if it holds vacuum.
Use hand pump. Put 18 lbs of vac
Two links I have been searching for
1 is a full wiring diagram of car
I had it posted on other sites
2nd
Was from 4eyed guys
Full service manual with pc/ed section for codes
Also these codes
You got these with key on engine off?
What about key on engine running test?
It can't be clogged exhaust. I just installed the shorties, off road X, and Pypes mufflers about 4 months ago.
TDC does seem to line up. When I get air coming out of the #1 plug hole, the rotor is pointing at about 12 o' clock and the balancer is at TDC.
I have a new MAP sensor and the original one, there is no difference when swapping them.
I just let the car sit for a few days with the battery disconnected, then got it warmed up and re checked the codes.
Key on engine off: 67, 81, 85, 82, 84, 11
Key on engine running: 42, 92, 33
I think I'm getting the code 67 from my A/C. It seems to turn on, on it's own after the car gets to operating temp(no matter what the selector is on). I have removed all the emissions equipment; TAD, TAB, EGR, EVP, and plugged the vacuum ports off, so the codes 81, 82, 84, 85, & 33 are expected.
I also decided to try "the fix", to the computer while the car was sitting. I expanded the prongs coming out of the computer that connect to the main harness, but that made no difference.
TDC does seem to line up. When I get air coming out of the #1 plug hole, the rotor is pointing at about 12 o' clock and the balancer is at TDC.
I have a new MAP sensor and the original one, there is no difference when swapping them.
I just let the car sit for a few days with the battery disconnected, then got it warmed up and re checked the codes.
Key on engine off: 67, 81, 85, 82, 84, 11
Key on engine running: 42, 92, 33
I think I'm getting the code 67 from my A/C. It seems to turn on, on it's own after the car gets to operating temp(no matter what the selector is on). I have removed all the emissions equipment; TAD, TAB, EGR, EVP, and plugged the vacuum ports off, so the codes 81, 82, 84, 85, & 33 are expected.
I also decided to try "the fix", to the computer while the car was sitting. I expanded the prongs coming out of the computer that connect to the main harness, but that made no difference.
Code 42/92 are worth looking into, but keep in mind they could be a result of how the car is running and unable to control the fuel trim.
42/92 are system rich. Run the codes one more time and run a cylinder balance test. Run it 3 times and verify you get a 90 each time to eliminate a misfire as the source of running rich.
Next, you can test the O2 sensors.
87-90 5.0 Mustangs:
Computer pin 43 Dark blue/Lt green – LH O2 sensor
Computer pin 29 Dark Green/Pink – RH O2 sensor
The computer pins are 29 (LH O2 with a dark green/pink wire) and 43 (RH O2 with a dark blue/pink wire). Use the ground next to the computer to ground the voltmeter. The O2 sensor voltage should switch between .2-.9 volt at idle.
42/92 are system rich. Run the codes one more time and run a cylinder balance test. Run it 3 times and verify you get a 90 each time to eliminate a misfire as the source of running rich.
Next, you can test the O2 sensors.
87-90 5.0 Mustangs:
Computer pin 43 Dark blue/Lt green – LH O2 sensor
Computer pin 29 Dark Green/Pink – RH O2 sensor
The computer pins are 29 (LH O2 with a dark green/pink wire) and 43 (RH O2 with a dark blue/pink wire). Use the ground next to the computer to ground the voltmeter. The O2 sensor voltage should switch between .2-.9 volt at idle.
Does anything change if you block off brake vacuum?
What firing order?
I would assume it to back fire
But 4 cylinders do match
I would assume it to back fire
But 4 cylinders do match
If I test the O2 pins on the computer they stay at 0.9v, sometimes they'll dip down to 0.8 but it mostly stays at 0.9 which I guess makes sense it it's running very rich.
With the vacuum gauge hooked up, I tried isolating sections of the vacuum system and there was no change with the brake booster blocked off.
I couldn't get it to do the cylinder balance test, but it seems like it's not just a single cylinder as they all seem to fire. The noid light test was the same on every injector, verified there is spark leaving the cap at every wire. It's the HO firing order, which I've verified and reverified is correct quite a few times. If I rev the engine, it sounds and feels healthy.
This is the reason why I understand when people ditch EFI for a carb. I will never do that, but this has me looking at the Holley Terminator X kit.
With the vacuum gauge hooked up, I tried isolating sections of the vacuum system and there was no change with the brake booster blocked off.
I couldn't get it to do the cylinder balance test, but it seems like it's not just a single cylinder as they all seem to fire. The noid light test was the same on every injector, verified there is spark leaving the cap at every wire. It's the HO firing order, which I've verified and reverified is correct quite a few times. If I rev the engine, it sounds and feels healthy.
This is the reason why I understand when people ditch EFI for a carb. I will never do that, but this has me looking at the Holley Terminator X kit.
Have you been on stangnet?
The moderator for this section is awesome hission50 iirc was screen name
It’s been a couple yrs since I’ve visited but he was extremely helpful
The moderator for this section is awesome hission50 iirc was screen name
It’s been a couple yrs since I’ve visited but he was extremely helpful
Quick Tech: How to Read a Vacuum Gauge to Pinpoint Engine Problems - OnAllCylinders
What’s your guage doing?
What’s your guage doing?
Yeah I've also got a thread on Stangnet about this.
With a vacuum gauge hooked up, it'll read around 14-16" with a little bit of fluctuation. I was assuming the fluctuation was from the idle surging...
The spark plugs(new Motorcraft AWSF32C) are all gapped at .052ish. I double checked them the other day.
With a vacuum gauge hooked up, it'll read around 14-16" with a little bit of fluctuation. I was assuming the fluctuation was from the idle surging...
The spark plugs(new Motorcraft AWSF32C) are all gapped at .052ish. I double checked them the other day.
The problem is 30 year old wiring and ECU's that have component failure internally (bad caps).
With that said, have you pulled the ECU out to inspect the capacitors?
Yeah the ECU is good. A bad DVOM lead me down a path of replacing the factory ECU about a month ago, which was actually good. It got replaced with a refurbished ECU and there were no changes whatsoever.
I had some free time today, so I double checked a few different things. The computer was already pulled out and battery disconnected, so I decided to test wire continuity for pretty much every sensor. MAP, TPS, IAC, ECT, ACT, O2s, and the injectors I could get to all had good continuity from the sensor to computer connector.
I did discover that the wires going to the A/C WOT relay were corroded to the point that some of the bare wires were touching each other. I fixed it to where the wires don't touch, but that didn't change anything with the idle.
Re-verified timing @ 14 degrees. Tried changing it a little each way, but it seems to have the best vacuum reading at 14 degrees. The vacuum reading surges with the idle from 15" to about 14. This was with the idle at about 750 and surging. At some points the idle would come up on it's own to about 1000 and the vacuum would hold about 20" with no variations.
Tried adjusting the TB set screw that changes the idle, but no luck. Idle either surges or ends up being way too high(1500+).
I did discover that the wires going to the A/C WOT relay were corroded to the point that some of the bare wires were touching each other. I fixed it to where the wires don't touch, but that didn't change anything with the idle.
Re-verified timing @ 14 degrees. Tried changing it a little each way, but it seems to have the best vacuum reading at 14 degrees. The vacuum reading surges with the idle from 15" to about 14. This was with the idle at about 750 and surging. At some points the idle would come up on it's own to about 1000 and the vacuum would hold about 20" with no variations.
Tried adjusting the TB set screw that changes the idle, but no luck. Idle either surges or ends up being way too high(1500+).
www.rothfam.com - /svo/reference/
Here is that link I was looking for
Has 1986 wiring diagram of the car like a road map instead of page by page pdf
Also has the ford pc/ed manual for codes
These aren’t on veryusefull or mustangtech
Also notice your in SA.
I live in Poteet
Here is that link I was looking for
Has 1986 wiring diagram of the car like a road map instead of page by page pdf
Also has the ford pc/ed manual for codes
These aren’t on veryusefull or mustangtech
Also notice your in SA.
I live in Poteet
Poteet isn't far at all.
Thank you for posting the links to those diagrams! I think I had seen a few of those diagrams before when I first started trying to figure this out. I ran through most of the sensor tests, and found that the MAP sensor is not at all close to passing the sensor test. With the key on engine off I get 2.6v on the MAP/BP wire. The table says it should be somewhere within 1.51-1.66v for my elevation. This was on the MAP sensor I bought off Amazon for $20. I swapped that sensor to the original one I took off, and got the exact same reading of 2.6v on the MAP/BP wire. That original sensor is 34yrs old and appears to have a small crack next to where the harness plugs in, so I don't trust that that sensor is good. Also had doubts about the cheap Amazon sensor... The diagram says to apply a vacuum pump(which I don't have) to it and vary the vacuum. I started the car which definitely applied vacuum to it, and it still stayed at 2.6v. Never had a MAP code at any point, but I'll try replacing it anyways.
Thank you for posting the links to those diagrams! I think I had seen a few of those diagrams before when I first started trying to figure this out. I ran through most of the sensor tests, and found that the MAP sensor is not at all close to passing the sensor test. With the key on engine off I get 2.6v on the MAP/BP wire. The table says it should be somewhere within 1.51-1.66v for my elevation. This was on the MAP sensor I bought off Amazon for $20. I swapped that sensor to the original one I took off, and got the exact same reading of 2.6v on the MAP/BP wire. That original sensor is 34yrs old and appears to have a small crack next to where the harness plugs in, so I don't trust that that sensor is good. Also had doubts about the cheap Amazon sensor... The diagram says to apply a vacuum pump(which I don't have) to it and vary the vacuum. I started the car which definitely applied vacuum to it, and it still stayed at 2.6v. Never had a MAP code at any point, but I'll try replacing it anyways.
Harbor freight sells mighty vac for around 50 bucks
Not a tool used a lot but worth having
You could also use another car for vacuum to test sensor
Any chance you can post a few picks of motor and maybe a video
How old is the gas
You say you set timing a few times.
This was were my buddy’s truck had issues.
Feeling hole for pressure to set at tdc
Once we did a visual on piston set to top than stabbed distibutor
It ran strong but shook so bad. Like cams.
Where your at now Sounds so much the same.
From reading this is more a common issue than you would think
None of your codes point to actual problem other than running pig rich
67 would be the only issue but not on motor issue
When it’s running
If you kill a cylinder does it react?
I enjoy these hard to find problems
Not a tool used a lot but worth having
You could also use another car for vacuum to test sensor
Any chance you can post a few picks of motor and maybe a video
How old is the gas
You say you set timing a few times.
This was were my buddy’s truck had issues.
Feeling hole for pressure to set at tdc
Once we did a visual on piston set to top than stabbed distibutor
It ran strong but shook so bad. Like cams.
Where your at now Sounds so much the same.
From reading this is more a common issue than you would think
None of your codes point to actual problem other than running pig rich
67 would be the only issue but not on motor issue
When it’s running
If you kill a cylinder does it react?
I enjoy these hard to find problems
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