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Discussion Starter #21
It's been a while just wanted to give an update. So I ended up driving it a little more and it lost power significantly, barely got it home. It will barely idle or move and it is putting out black smoke and smells like gas. So I did a fuel pressure test it only had 49psi. So I swapped the filter and bumped it up to 51psi but thats still low and it has a new fuel pump already that I installed so I want to replace the fuel pressure regulator just haven't had time. I did do another compression test and all cylinders were only 70psi give or take 5psi? Maybe the lack of fuel pressure caused the computer to try and dump more fuel and washed the cylinders. I've never had a engine lose compression on all cylinders before. Also a side note the engine had been making a noise that I couldn't pinpoint where it was coming from kinda sounded like the cam was scoring or maybe timing belt idler pulley. I have looked at the cam and it had light scoring on the lobes but not bad but never looked under the bearing caps.
 

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You need to get the fuel diluted oil out of the engine and get fresh oil in there.
Fuel diluted oil will wash down the cylinder walls and cause a lack of lubrication on other crucial parts.

When you checked fuel pressure with the engine running was the vacuum line removed from the FPR?
If no then you are not reading fuel pressure correctly.
Static (KOEO) rail pressure needs to be 53 - 57 PSI, with the engine running rail pressure will drop 1 PSI for every 2 " HG applied to the FPR.
If you have 55 PSI static and 18" HG when you start the car, rail pressure will drop by 9 PSI to 46 PSI.
It is the combination of push (rail pressure) and pull ( engine vacuum) that maintains the 55 PSI across the tip of the injectors under all operating conditions.
 

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Discussion Starter #23
I didn't unhook the vacuum line when I tested before. So I should have 53-57 psi with the vacuum disconnected from fpr while the engine is running? I will try first thing in morning and get back to you. thanks
 

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Discussion Starter #24
So it's holding at 55psi with the vacuum line disconnected. It's idling really rough and has black smoke coming from the exhaust. So would that mean that either the injectors are bad or possibly the computer not switching the injectors? It has no fault codes. Possibly just that it has lost compression and isn't burning all the fuel. But what would have caused it to lose compression in all cylinders evenly? Where would I go next for diagnosis?
 

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If you are running that rich you probably have fuel diluted oil that has washed down the cylinder walls which will lower compression although there may be other causes.

Causes of running Black Rich...
1)Spark Plug Fouling
a)If all 4 spark plugs are fouled continue to step 2.
b)If only one or two are fouled, post back.
2)Fuel Pressure
You already determined that Fuel Pressure is OK...
a)When you shut the engine off did fuel pressure hold or drop quickly/suddenly, pressure should hold for anywhere from 15 - 30 minutes after the engine is shut off.
b)If pressure drops quickly/suddenly, post back.
c)If pressure held there are no leaking injectors.
3)Map Sensor Circuit or Loss Of Engine Vacuum
The MAP Sensor is the Dominant Fuel Control Sensor (The Air Charge/Coolant Temp sensors play a minor role and the O2 sensor is only a fuel trimmer) on the vehicle, it looks at the difference between Atmospheric and Manifold Pressure to determine how much air is in the engine and the controller uses this information to calculate Ignition Timing and Injector Pulse Width.
When engine vacuum drops that indicates to the controller that more air has entered the engine and it adds more fuel.
If engine vacuum is low due to an engine problem such as Low Compression, Cam/Ignition Timing being incorrect (which will cause low compression) or a Restricted/Broken Vacuum Line to the Baro Solenoid or Map Sensor then you will run rich.
a)What is engine vacuum reading at a manifold source?
15 - 20" HG is the normal range, below 15" HG you are low and will have to determine the cause.
LINK- b)If engine vacuum is low then start by verifying Cam Timing is correct.
b)If engine vacuum reads normal at a manifold source tee a vacuum gauge into the vacuum line between the manifold and Baro solenoid, is vacuum reading 15 - 20" HG?
IF OK...
c)Tee a vacuum gauge inline between the Baro solenoid and the Map sensor, is vacuum reading 15 - 20" HG?
If OK...
d)Check Map Sensor Calibration

4)If all 4 plugs are fouled, fuel pressure holds when the engine is shut off, cam timing is correct and there are no restricted/broken vacuum lines between the manifold/baro solenoid/map sensor but engine vacuum is low and you have low compression you will need to determine why compression is low.
A Cylinder Leakdown Test will tell you where the loss of compression is coming from.
Before performing another compression test and a cylinder leakdown test remove the fuel diluted oil and filter from the engine and get fresh oil/filter in the car. (Any 10W-30 Dino oil will do)
Disconnect/remove the ASD Relay (on a 91 it is in the PDC and should labeled "Auto Shutdown Relay") and crank the engine 10 - 15 seconds to get fresh oil into the cylinders and other vital parts.
LINK- SPECS-Engine Compression.jpg

1991 Daytona ASD Relay Location
91 Daytona System Diagram 6.jpg

I am not home on weekends but I do check my phone once in a while should you need/require more info/assistance.
 

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Discussion Starter #26
When I tested the fuel pressure it stayed at a solid 55psi while running and when I shut it off it dropped immediately to 52psi and within less than 60 seconds it had dropped to 48psi. The oil is black and smells like gas and the plugs are black. So I think the injectors are leaking so I'm going to pull them and clean them and see if that fixes the problem. I will also change the oil and filter and atleast clean the spark plugs because they are new. I would like to replace everything new but money is tight right now. Do you have any other suggestions? thanks
 

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If all four plugs are fouled you do not have leaking injectors, your issue is something affecting all cylinders, Checking Engine Vacuum is your next step.

Just some info...
Injectors get dirty on the inside, removing them to clean is a futile effort.
Preferably injectors should be cleaned with a chemical cleaner used in a pressurized canister and the vehicles fuel system disabled with the engine running on the chemical only.
Your only other choice is an over the counter fuel additive, which one??? They all make claims as being the best and all contain chemicals that are already in gasoline, I am not a fan of additives.
The only true way to tell if an injector is clogged is with an injector pulse tester and fuel pressure gauge.
 

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Discussion Starter #29
it doesn't have any vaccum leaks I sprayed and traced all the vacuum lines multiple times but it does have a old map sensor from a wrecking yard that I got when I had to re-wire the plug for the map sensor because it had a 3bar map sensor in it when I first got it. It also has a universal o2 sensor that came in it when I got it and it's hard wired. Could it some how have an internal vacuum leak? The factory boost gauge always seems to read accurate. It ran good for over a year as a daily driver until I changed the oil with the mobile 1 synthetic and that's when the problem arose.
 

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Discussion Starter #31
Well when I first started it, it reads 7 lbs of vacuum and slowly goes down to 0 once it starts warming up but it lopes really bad and barely stays running, it will smooth out if you press the gas peddle and hold it at a steady rpm but will go right back to a very rough lope and has no power when trying to move or under load.Then after sitting a few minutes I can restart it and it even attempts to idle up like it normally would while engine is cold till warms up and lopes less and the vacuum will hold at 11 psi but still remains sluggish and no power. This is the dash vacuum/boost gauge by the way I don't have a vacuum tester or gauge other than that. I also haven't let it run very long to fully warm up only like 5 min at a time because I don't want to cause any more damage.
 

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Your engine vacuum is extremely low which is why you are running so rich.
Engine vacuum at idle needs to be 15 - 20"HG.

My suggestion to you is to first check Cam Timing, the belt may have jumped, has missing teeth, etc.

Here is the procedure...
 

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Discussion Starter #33
Ok my car is parked outside and it's cold where I live right now so might be a while until I can get it in my shop but I will post back with my results. Thanks a lot
 

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Discussion Starter #35
So I finally got the shelby in the shop and low and behold the timing was off 2-3 teeth on the cam sprocket and the balance shaft was a couple teeth off as well and I think that the balance shaft was off since I got it due to the distributor position. The tensioner pulley went bad it was making a metallic bearing noise that I couldn't pin down. I'm assuming that it got hot and the belt got hot and stretched or got soft and jumped time. Thanks again for all your help! I will post back once I get it back together.
 

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Discussion Starter #36
I put it back together just to find out that it went out of time after trying to start it and found out that the woodruff key for the crank pulley had worn and gouged the crank but I was able to replace the woodruff key and now it's running again and vacuum is at 15 but after test driving it's still smoking after accelerating sometimes but only when I'm driving so I can't tell if it's blue or black smoke but it no longer smells like gas
 

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Keep an eye on the spark plugs for any signs of fouling, that will let you know if you are burning oil or are running rich.
 

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Discussion Starter #38
Will do thanks. It seems to be using oil still and not leaking it and the plugs that were already in it were black with carbon.
 

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Hey everybody I have an issue with my 91 2.5 daytona shelby garrett turbo 2 intercooled. Recently I switched over to synthetic mobile 1 and I noticed it started using oil and started smoking sometimes Nox Vidmate VLC after a heavy acceleration not during acceleration and not when idling or cold starts just after heavy accelerations for a few seconds and then clears up. Does anybody have any ideas what it could be maybe a bad pcv valve?
you dont have much too loose. it needs a rebuild or at the very least a hone and ring job.
 
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