Location: Lansing, MI
Posts: 1,168
My VIN: 10270
Just run some vac hose between the pump and the lower chamber on the WUR. The other vac connection should be open and unobstructed during this test. When the car is warm and the control pressure gauge reads the warm temp pressure, apply about 15in/Hg vacuum to the WUR and note the control pressure reading. This will enrich the mixture and your car will run rough but shouldn't stall.Originally Posted by Trstno1
Luke S :: 10270 :: 82 Grey 5-Speed :: Single Watercooled T3 .60/.48 :: Borla Exhaust :: MSD Ignition :: MS3X Fully SFI Odd-fire EFI :: DevilsOwn Methanol Injection
Location: Anchorage, Alaska
Posts: 847
My VIN: 5625
Ok- I'm trying to wrap my head around this, would these be the steps I need to take? Sorry to be dense on this one I just don't want to screw it up....
so I should keep the vacuum and electrical both hooked up on the WUR until I get the 3.5 bar of control pressure when the engine is warm.
Then I disconnect both the WUR vacuum lines. Hook up the vacuum pump to the lower chamber while the upper chamber has nothing connected to it. Leave the electrical connection connected to WUR.
Apply 15 in/Hg vacuum to WUR and note the control pressure reading.
this should all take place with the engine running-
What control pressure am I looking for / not looking for?
You can't buy happiness, but you can buy a DeLorean and that's sort of the same thing....
Location: Lansing, MI
Posts: 1,168
My VIN: 10270
That's pretty much it. I'd disconnect the vac lines when cold just for convenience. Be sure to plug the vac line coming from the under the intake manifold or it'll run rough from the vacuum leak.
When hot do the test with the pump and check the manual (or my earlier post) for what control pressure should then read.
Luke S :: 10270 :: 82 Grey 5-Speed :: Single Watercooled T3 .60/.48 :: Borla Exhaust :: MSD Ignition :: MS3X Fully SFI Odd-fire EFI :: DevilsOwn Methanol Injection
Location: Anchorage, Alaska
Posts: 847
My VIN: 5625
Ok.
So after warm control pressure test I get 1.6 bar which right in the middle of the manuals 1.4-1.8 bar. So, results are that the WUR is good.
Hmmmmm, do you think the vacuum control valve taking longer than the 10-12 seconds the manual states to bleed down is an issue? Mine comes in at a little over 16 seconds to bleed from 16hg to 8 Hg.
I guess next up would be smoke test to find any vacuum leaks.....
You can't buy happiness, but you can buy a DeLorean and that's sort of the same thing....
Location: Lansing, MI
Posts: 1,168
My VIN: 10270
Vacuum enrichment is only active when you hit the throttle. If it ran rough while the vac lines were disconnected and the line from under the intake was capped, your problem lies elsewhere. I don't think it's the VDV.
With as hard as it is to start and if it isn't afterfiring or producing black smoke, I'd think you were lean (vacuum leak or misadjusted CO) but then typically you'd see up to 100% duty cycle on the dwell meter test. I'm thinking a misfiring plug, bad injector, fuel distributor issue, even a valve/piston issue, etc.
If it's been going on long enough you may be able to read the spark plugs and see which one(s) it is. If it were my engine this is what I'd probably do. Pull a few and see how they look compared to spark plug chart.
The only time I've made my own engine run genuinely rough through misadjustments was when converting to MSD ignition. I had the hall effect pickup wired backwards and the timing was waaaaaaaaay out in left field. Like instead of reading the marks between 12 o'clock & 1 o'clock on the crank pulley, they were reading somewhere around 9-10 o'clock. The motor sounded like a Harley and wasn't thrilled about revving. I reversed the wires and it went back to happy & normal.
Luke S :: 10270 :: 82 Grey 5-Speed :: Single Watercooled T3 .60/.48 :: Borla Exhaust :: MSD Ignition :: MS3X Fully SFI Odd-fire EFI :: DevilsOwn Methanol Injection
Location: Anchorage, Alaska
Posts: 847
My VIN: 5625
Yeah.... this dang thing is starting to kick my butt. I am going to order new injectors next and see what happens.... Man, I hope I don't have a valve or piston issue. I did conduct a compression test and they came back mostly good. I did have one cylinder that was a little lower than the others but nothing bad.
You can't buy happiness, but you can buy a DeLorean and that's sort of the same thing....
Location: Anchorage, Alaska
Posts: 847
My VIN: 5625
Hey guys -
So I finally shelled out for new injectors and I cant be happier!! The spray pattern on these new 022's from DMCMW are 100% better than the ones I had professionally cleaned! The better part is that my engine vibration is almost completely gone! Check out this video:
https://www.youtube.com/watch?v=cs7iDYuHhXY
The issue that still remains:
- I still do have a bit of a cold start issue where the car wants to crank 4-7 seconds before firing up, then it will hunt pretty good for the next minute until it warms up and settles at 775 RPM. I understand the hunting upon start up is normal depending on the ambient temperature but the excess crank time prior to engine start seems excessive when comparing how my car cold starts vs. others I have seen on youtube. Though it should be known that it starts like a champ immediately when ever the car is warm. Is it possible to get it to act the same way when cold?
I have tested the cold start valve and thermo-time switch operation and all seems nominal there. The WUR tested good, though maybe the cold start control pressure was a little higher than normal. Is there anything else that could cause the cold start issue? Failed rest pressure? vacuum leak(s)?
As always, thanks everyone for your help!
You can't buy happiness, but you can buy a DeLorean and that's sort of the same thing....
Location: Leonardtown, MD
Posts: 9,003
My VIN: 03572
I know when my engine needs the CSV to start because it takes one second of cranking to fire. I use my "hot start" relay to fire the CSV and have no thermal time switch connected. Now I probably don't have the cold temps you do but if my car sits for a week or more, it needs the CSV to start.
Now why your car takes 5 to 7 seconds of cranking to start. My guess would be it's fuel related since that long cranking is just letting the CSV keep priming with some gas.
Location: Anchorage, Alaska
Posts: 847
My VIN: 5625
Is there a chance that the CSV is not injecting enough fuel? I have witnessed it spraying into a jar when cold and plugging my finger over the CSV inlet. What I don't know is if it's actually injecting enough fuel into the intake. How much fuel should it spray in comparison with that of a fuel injector?
Shouldn't I be able to test it by unplugging the CSV and pressing down on the air inlet plate to inject fuel into the cylinders while the pump is priming prior to crank? I would assume that if it fired right off then it would be an issue of fuel quantity coming from the CSV right?
Last edited by Trstno1; 03-21-2016 at 08:22 PM.
You can't buy happiness, but you can buy a DeLorean and that's sort of the same thing....
Location: Leonardtown, MD
Posts: 9,003
My VIN: 03572
It is not much fuel flow from the CSV. I have stuck it in a jar to test it and the amount of fuel is much less than the normal injector. I never though to test if the pressing the air plate increased the flow.
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Dave M vin 03572