81 OB running bad need advice(Change to Timing Belt Issue)
08-03-2009, 05:09 PM
#16
Nordschleife Master
Sorry, I misread your title, I thought it said "need bad advice". 
Take a look at Porken's post with diagrams at the end of this thread.
https://rennlist.com/forums/928-foru...d-results.html
Take a look at Porken's post with diagrams at the end of this thread.
https://rennlist.com/forums/928-foru...d-results.html
08-03-2009, 05:12 PM
#17
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on the 81, it is a measurement BETWEEN the pins, not a measurement between each pin and grounds, that is not until the LH. (BTW, on an LH temp2 you wouldn't get a reading between the pins)
Your 277 reading that was at what temp? You should get a cold reading and a reading at operating temp.
Vacuum hoses usually create lean conditions.
Temp2, afm, FPR, injectors can all cause rich conditions, what else?
However, from your symptoms this could also be alot of other things. Bad gas mileage and low power can be lots of stuff including spark etc...
I would think to open the hood and start simple. Touch everything to see it is ok and secured properly, check the distributer cap, rotor, do firefly test, check for loose connectors etc., do all the easy stuff
Your 277 reading that was at what temp? You should get a cold reading and a reading at operating temp.
Vacuum hoses usually create lean conditions.
Temp2, afm, FPR, injectors can all cause rich conditions, what else?
However, from your symptoms this could also be alot of other things. Bad gas mileage and low power can be lots of stuff including spark etc...
I would think to open the hood and start simple. Touch everything to see it is ok and secured properly, check the distributer cap, rotor, do firefly test, check for loose connectors etc., do all the easy stuff
08-03-2009, 05:34 PM
#19
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so what was your fuel pressure? I think it should be like 27psi? FPR holds vacuum? no fuel at vacuum connections of FPR and Dampners?
Another thought while I was thinking about it because it was in 'race' type conditions. Did you pull a plug? Now that it has been rich for this long I wonder about your O2 sensor too, although that thing would explain WOT settings
Another thought while I was thinking about it because it was in 'race' type conditions. Did you pull a plug? Now that it has been rich for this long I wonder about your O2 sensor too, although that thing would explain WOT settings
08-03-2009, 05:49 PM
#20
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I'm still at work gonna be home shortly. Just changed passside FPR for fuel in the diaphram. Did that same time I checked the vaccum lines and changed the coil because of leaking oil.
08-03-2009, 09:52 PM
#21
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Jason, still could have poped a vac line due to the type of driving you were doing, and may have not gotten one on snug enough. I would also check the dist to make shure that it did not slip due to a possible not snuged down bolt from last time that you set timming. I know you probably are shure all O.K., but also an easy miss.
08-04-2009, 12:53 AM
#22
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Ok here's what I got. Vacuum is good. Only found a small bit of leakage at the fuel dampener. Very slight. Still held pressure not perfect but good. Fuel pressure was about 36-37 with no variance. Steady the whole time from idle to about 3k rpm. It was late so I couldn't open it up. I found no connector or vacuum hoses off. The one thing I'm thinking is what are the odds of the new coil I installed going bad? Car is definitely running very rich. I'm going to check the timing next and figure out how to test the coil. Maybe autozone can test them. Any other thoughts guys? I was also thinking about the fuel filter getting clogged(We have dirty gas here). It would make sense about not getting enough flow at or after high speed runs but I don't think a clogged filter would lead to a too rich condition.
Also distributor is tight.
Also distributor is tight.
08-04-2009, 12:58 AM
#23
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One of my friends also wondered if the timing belt may have jumped a tooth. What would the signs of that be god forbid?
08-04-2009, 01:16 AM
#24
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Ok, we found the problem unless you did something wrong in diagnosis.
I need you to pull off your lunchbox and start the car and measure idle pressure, then remove both vacuum lines to both your FPRs in the back.
under vacuum your idle fuel pressure should be
30psi
removing the vacuum lines will give you full throttle readings (0 vacuum) which should be roughly
36psi
There should never be steady fuel pressure. If you are always at 36-37 yes you would run rich MOST of the time, basically 3/4 throttle and below.
when we get this squared away we can investigate further to high speed problems. You need to mightyvac those FPRs otherwise you have a vacuum line melted together or broke somewhere.
As far as WOT at this point maybe fouled plugs? lets get the fuel pressure fixed first
I need you to pull off your lunchbox and start the car and measure idle pressure, then remove both vacuum lines to both your FPRs in the back.
under vacuum your idle fuel pressure should be
30psi
removing the vacuum lines will give you full throttle readings (0 vacuum) which should be roughly
36psi
There should never be steady fuel pressure. If you are always at 36-37 yes you would run rich MOST of the time, basically 3/4 throttle and below.
when we get this squared away we can investigate further to high speed problems. You need to mightyvac those FPRs otherwise you have a vacuum line melted together or broke somewhere.
As far as WOT at this point maybe fouled plugs? lets get the fuel pressure fixed first
08-04-2009, 01:17 AM
#25
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Jumping a tooth? Im not sure exactly how much timing a tooth is worth on a 16v, but it wont cause rich condition, it would cause drivability issue, roughness, backfiring, etc...
08-04-2009, 01:24 AM
#26
Nordschleife Master
Posted on RW,
Your FPR or fuel damper is bad. If there is ANY fuel comming out of the vacuum port you need to replace that item immediately.
BTW I have a practically new damper for the L-jet sitting here. yours for shipping. PM me.
Your FPR or fuel damper is bad. If there is ANY fuel comming out of the vacuum port you need to replace that item immediately.
BTW I have a practically new damper for the L-jet sitting here. yours for shipping. PM me.
08-04-2009, 01:29 AM
#27
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Ok, we found the problem unless you did something wrong in diagnosis.
I need you to pull off your lunchbox and start the car and measure idle pressure, then remove both vacuum lines to both your FPRs in the back.
under vacuum your idle fuel pressure should be
30psi
removing the vacuum lines will give you full throttle readings (0 vacuum) which should be roughly
36psi
There should never be steady fuel pressure. If you are always at 36-37 yes you would run rich MOST of the time, basically 3/4 throttle and below.
when we get this squared away we can investigate further to high speed problems. You need to mightyvac those FPRs otherwise you have a vacuum line melted together or broke somewhere.
As far as WOT at this point maybe fouled plugs? lets get the fuel pressure fixed first
I need you to pull off your lunchbox and start the car and measure idle pressure, then remove both vacuum lines to both your FPRs in the back.
under vacuum your idle fuel pressure should be
30psi
removing the vacuum lines will give you full throttle readings (0 vacuum) which should be roughly
36psi
There should never be steady fuel pressure. If you are always at 36-37 yes you would run rich MOST of the time, basically 3/4 throttle and below.
when we get this squared away we can investigate further to high speed problems. You need to mightyvac those FPRs otherwise you have a vacuum line melted together or broke somewhere.
As far as WOT at this point maybe fouled plugs? lets get the fuel pressure fixed first
08-04-2009, 01:31 AM
#28
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08-04-2009, 01:37 AM
#29
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yes vacuum pulls the diaphram back and lowers the pressure for idle. The simple test of removing the lines and check pressure is better than the vacuum test as you don't really need to know that yet.
Definantly get that leaky one replaced
Definantly get that leaky one replaced