Close



Page 15 of 19 FirstFirst ... 51314151617 ... LastLast
Results 351 to 375 of 464
  1. #351
    FEP Power Member
    Join Date
    Nov 2007
    Location
    San Mateo, CA
    Posts
    1,635

    Default

    Quote Originally Posted by m81mclaren View Post
    Thanks for the comment Kevin. Are you suggesting that my car could be cutting out because of an overheating issue? Is there some kind of computer protection shutdown if the car reaches a temp ceiling?
    No, there is nothing to stop the engine if it gets hot. I'm just saying, keep an eye on the temperature in case it runs hot.

    Engine cutting out is either fuel or ignition. I just went through a bad fuel pump issue and it was easy to diagnose with a fuel pressure gauge. Fuel pumps do not age well and will fail if not used.
    Fox Body/3rd Gen MCA Gold Card Judge
    84 SVO 24K miles, 85 Mclaren Capri Vert. 84 GT Turbo Vert.
    88 Mclaren Mustang Vert 20K miles, 89 Mustang LX Sport Vert,
    03 Mach 1 7900 miles, 74 Mustang II, 69 Mustang, 67 Mustang, 14 Mustang CS/GT,
    15 F150 FTX Tuscany, 16 F250 Crewcab, 67 Tbird 47K miles

  2. #352
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,850

    Default fuel flow

    Back to square one.
    Too bad we aren't neighbors.
    Reread some of the early thread posts. 2010? Geez thought that date was a mistake.
    Noticed the fuel tank has drain and separate fuel level sender for the SW fuel gauge. McLaren mods i assume.
    Never had an over temp engine shutdown on any engine here. Did McLaren add one?
    Of course, all fuel lines are connected to the correct fittings and not accidentally reversed.

    I doubt anything is wrong with the tank. Could peek inside by removing pickup assy, rather than whole tank.
    Almost empty tank of course. But that is a lot of work.

    The clear filter. To see whats going on with fuel quickly.
    Should see plenty of fuel in it during, and for a while, after shutdown.
    After shutdown, the fuel pump relieves pressure allowing fuel in the carb line to drain back into tank thru the return line.
    Saves the needle and seat i guess.

    One thing i did once was temp pinch off the rubber hose return line at the fuel pump.
    Fuel never drained out of filter when car was parked after this was done.
    Made a block off hose. Ran it for years that way.

    Reason why i did this back in the 80's?
    Curious about how much fuel pressure the engine was getting under boost.
    Temp installed fuel pressure gauge outside of car taped to windshield wiper.
    A cheap hand held vac/pressure gauge.
    With return line pinched off, 5# all the time.
    Return line open, dropped to 3-4# under boost. Never cut out, or noticed any power diff.
    Eventually reconnected fuel return line like it was from factory.
    Its no doubt for emissions. Read that returning fuel all the time agitated the vapors out of it.
    Over thinking things or maybe not. Gonna block it off again in 2019.

    Now, simple ways i use to test fuel flow from tank.
    First pinch off that return line at the pump. Pinch off with clamp or tool.
    Run engine, check filter. Can drive it this way.

    Another way to test fuel is with main fuel tank offline. To see if there is a problem in tank.
    Disconnect both rubber lines back at tank pickup. Vapor line at tank top not a problem.
    Dunk both lines in a full gas can (now the temp fuel tank) on ground.
    Parked, run engine. 20 min or so. Observe fuel in filter, see if level changes.

    Or drive car with a gas can connected directly to fuel pump of car.
    Like in an outboard motor boats. Cars? Where to temp put tank safely?
    That would be like another gas tank or fuel cell to run engine without main tank connected.
    Easy with a pickup truck. Tank outside in bed of truck.

    Just some ideas, thoughts.
    Or take it in to a shop somewhere have someone figure it out if that's an option.
    Big thing is trusting someone with a car like that...
    Mine is stock and still leery of doing that. "That will be 2000.00......"
    For something simple they found, and not revealing true details.

  3. #353

    Default

    I had a similar issue with the 2.3 n/a in my Zephyr. It wouldn't maintain fuel pressure. It would run for about a mile then start cutting out and die. Then it would sit about 10 minutes and start back up and drive another mile and repeat. It had a new fuel pump, fuel filter, and sock on the fuel pickup. We blew air through the lines and they were clear.

    I thought maybe my new fuel pump was defective so I warranteed it, but the new one did the same thing. So I went and bought an electric universal low pressure fuel pump. After I put that on I had no more problems with fuel pressure or stalling.

    I'm thinking the problem was either I got two bad fuel pumps or the fuel pump lobe was wiped.
    Matt
    1980 Mercury Zephyr moredoor sleeper

    1988 Mustang GT hatch -- Explorer intake, GT40 heads with Trick Flow spring kit, Crane 1.7 rrs, E303 cam, 70mm MAF, 70mm throttle body, Kirban Kwik shifter w/ Pro 5.0 Deluxe handle, clutch quadrant and firewall adjuster, and 3.27s

    1986 Mercury Cougar 5.0 (sold), 1989 Lincoln Mark VII LSC 5.0 5 speed (sold)

  4. #354
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,850

    Default

    I knew people that added an electric fuel pump to make sure the mech one got fuel.
    The street race and dragstrip days. Prob helped stop vapor lock in hot summer.

    Electric fuel pump boost overcomes slow venting?
    Some suggest lack of tank venting. Pump cant pull hard enough once the air is out of tank.
    To fill tank, air has to come out. To empty tank, air has to go in.
    Air returns back in tank, process repeats.
    Fuel cap, charcoal canister purge valve, etc. Tank vents.
    Could always take fuel cap off when car starts acting up just for kicks.

  5. #355

    Default

    Great minds think alike! I was also thinking take the cap off or install a vented cap.

  6. #356

    Default

    Great ideas guys thank you. The venting issue could be real as the vent line by the tank on page 2 is still not connected as I did not see a port to actually connect it to.
    Current FEP:
    1980 M81 McLaren Carb Turbo 2.3T #003P ... IT'S ALIVE after a 22 year slumber thread!

    Past FEP:
    1986 Capri GS 5.0- very missed but in goods hands
    1985 LTD SSP- quick little fox 5.0

  7. #357
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,850

    Default

    Pic of mine. Factory connected tank vent hose with a splice to the hose going to front of car (Hose in thread post #44 pic 2).
    Name:  fuel tank install (1).jpg
Views: 155
Size:  146.8 KB

    The tank vent. Eventually connects to the charcoal canister.
    Name:  fuel tank out (22).jpg
Views: 154
Size:  69.0 KB

    Yours has the float sending unit in that spot. Part of McLaren M81 tank mods for the SW fuel gauge i presume.
    Good thing you had the tank reconditioned rather than have to mod a new one. That was a fair price.
    Attachment 125410
    Last edited by gr79; 12-11-2018 at 01:08 AM.

  8. #358

    Default

    Awesome GR thank you. Yes I had forgotten that my M81 SW sending unit was separate from the feed unit and took the spot where the vent line is supposed to go. I could probably figure out a way to retrofit the vent back but it seems obvious that eliminating the vent tube was intentional and presumably the car should function without it otherwise they wouldn't have done it in the first place and the car would not have been able to accumulate the original 22K miles. So, it seems I should be able to cross this off the list as a cause of the fuel delivery issue.

    I will pull the gas cap and see if it makes any difference plus will compare my new cap to the old one closely to see if my original was modified in any way to help with venting. I'm certain I had the stalling issue before I put the new gas cap in which was a very recent addition. I also confirmed that my fuel lines are correctly installed and routed to the fuel pump- that is large line to feed and small line to return. More head scratching to do but I'm back to leaning towards the in tank filter being a restriction (or more realistically some kind of vacuum line mismatch to the carb). I added the feed line filter thinking it should be there when perhaps I should have left it off. Having the clear filter in place would allow me to remove the feed line filter and eliminate that as an issue. I wonder if having three filters is creating a restriction (in tank, clear filter then filter on carb)? I should have had them add a drain plug to the tank when I had it rebuilt. Looks like there is some plug added probably for the cleaning process but it's not in the right place for a drain. Like you suggested as long as the tank is near empty I may be able to just pull the feed unit for inspection of the tank and filter removal without having to drop the whole thing. Again appreciate all the help thinking this through with remote diagnostics/suggestions!

    wrong spot to be drain plug...


    2010 post# 80


    with added filter on feed side back in 2011 post #105

    Fuel filter as it sits today after 3 days from last stall.
    Last edited by m81mclaren; 12-11-2018 at 06:04 PM.
    Current FEP:
    1980 M81 McLaren Carb Turbo 2.3T #003P ... IT'S ALIVE after a 22 year slumber thread!

    Past FEP:
    1986 Capri GS 5.0- very missed but in goods hands
    1985 LTD SSP- quick little fox 5.0

  9. #359
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,850

    Default

    I agree with the 22k assessment.
    Temp removal of gas cap would confirm if vent problem now exists.
    Wonder why the vent assy was deleted? Thought it was part of emissions.

    Doubt any vac line to carb would stop fuel from getting up to filter.
    Lack of fuel is upstream of carb. Tank, lines, fuel pump, filters.

    While fuel lines are off, could re blow air thru steel lines in case something loosened up and is obstructing.
    Disconnect both at fuel pump (fun when that shield is on) and at tank.
    Could add something at one end, say soda bottle, to trap anything that comes out to analyse like a doctor.

    Filter at carb.
    Should you decide to remove factory filter and keep just the clear one:
    A 1/8" x 5/16" brass barb fits, instead of the factory metal filter.
    Threads into carb air horn. Did use pipe tape. Careful- carb treads soft- will strip or cross thread.
    Clear filter hose clamps to it.
    My fitting bottoms out against carb because threads are shorter than the metal filter ones.
    Have done this on all the replacement carbs for a long time because i stripped a carb once over tightening the metal one.

    Attachment 125412Attachment 125413

  10. #360

    Default

    Thanks GR. Will blow out the lines again and remove the filter from the tank feed and inspect condition of tank. I may remove the OEM style carb filter and replace with barb as suggested. On your bottom carb picture you have two arrows. I capped the passenger side air horn (left arrow in your pic) that previously was not plugged. Do you know its function? I may pull it back off and see of that does anything.
    Current FEP:
    1980 M81 McLaren Carb Turbo 2.3T #003P ... IT'S ALIVE after a 22 year slumber thread!

    Past FEP:
    1986 Capri GS 5.0- very missed but in goods hands
    1985 LTD SSP- quick little fox 5.0

  11. #361
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,850

    Default Wednesday is 'Prince Spaghetti Day'

    Then there is our car's vac hose Ford spaghetti. It is Wednesday.

    Answer is #4 connection (in pic) positively affects idle quality, for one.
    My engine likes it connected per schematic. Far as i can tell, is a 'controlled' vac leak!

    Can identify 4 connections. See pic.
    On mine, #4 is connected to 1,2,3.

    Yours was prob similar, different, or the same.
    Like the fuel tank.

    Rechecked 1979 2.3T 49 state vac schematics.

    Using numbers in pic:
    -#3 is connected the same way.
    -White side of check valve is connected to tee same way.

    Different:
    -#4 barb is connected to #2 hose, black side of check valve.
    -#1 hose is connected directly to intake manifold tree.

    Dunno why or how they work this way but they do.

    Surprised cold engine idled at steady 500 rpm other day warming up in driveway. Has no choke.
    25 out, foot off gas pedal. Lights heater and rear defog were on. Just sayin its possible.
    Usually have to keep it alive with pedal for the few minutes of warm up.


    Your pic:
    Where is hose #2 connected to?
    Where is hose #1 connected to?

    Attachment 125426

  12. #362

    Default

    Ha ha she is a Princess in my case- a bit cranky and unpredictable! Appreciate the feedback and will double-check connection questions tonight and get back with you to see if we can identify anything blatantly wrong (I know there are likely a few as the turbo has been out before my ownership and some ports are still open or should not be plugged).

    One of the challenges is that vacuum line spaghetti changes year to year and whether its a CA or Federal standards car, high or low altitude, if you have A/C, etc. So one M81 may vary compared to another let alone what was in there from the factory. On my car I have found 1979 and 1980 parts even though it was built 7/80 plus there are some deviations from typical (McLaren or previous 2 owners). To make matters worse it started as a Federal car that has been BAR (Bureau of Automotive Repair) processed as an exception for CA so may have been further modified and may/may not conform to CA standards. The book is therefore a starting point! I have the EVT book for 1980 as my jump off point and a Holley 5200 Handbook by Mike Urich to try and learn more about carbs.
    Last edited by m81mclaren; 12-12-2018 at 01:19 PM.
    Current FEP:
    1980 M81 McLaren Carb Turbo 2.3T #003P ... IT'S ALIVE after a 22 year slumber thread!

    Past FEP:
    1986 Capri GS 5.0- very missed but in goods hands
    1985 LTD SSP- quick little fox 5.0

  13. #363

    Default

    Have you been able to drive this thing with any regularity or are the nickel/dime gremlins kicking it on you?
    84 Capri RS Turbo
    Vinemont, AL (formerly El Mirage, AZ)
    USAF (Ret)

  14. #364

    Default

    Oh I'm well into the nickel and dime stage for sure but that's all part of the process of getting a "barn find" actually roadworthy rather than just saying it "runs and drives"! I'm sure there will be more to come when i get to the braking system.

    Unfortunately have not been able to do anything on further troubleshooting of the fuel starvation issue as I threw out my back which simply requires time to get back to a functional state. I'm nearly there so this weekend I plan to pull the gas cap and see if that has an impact and retest. If the same result I'll pull the tank fuel feed unit and inspect the tank, remove the fill filter sock, then blow out the lines again. Then re-test. If same, I'll remove the secondary carb air horn plug I added and see what impact that makes if any and maybe try to join it to the primary horn vacuum system as well based on GR's setup. Appreciate all the helpful posts and IM's!
    Last edited by m81mclaren; 12-26-2018 at 12:51 PM.
    Current FEP:
    1980 M81 McLaren Carb Turbo 2.3T #003P ... IT'S ALIVE after a 22 year slumber thread!

    Past FEP:
    1986 Capri GS 5.0- very missed but in goods hands
    1985 LTD SSP- quick little fox 5.0

  15. #365

    Default

    Ok so finally back at it. Removed the gas cap and the added/removed the secondary air horn with the same stalling result while getting on it (I sure love the turbo spool sound) Clear filter empty as before and after 30 minutes back to half full. So a quick bite to eat then we'll pull the feed line and inspect, blow out the lines and remove the feed filter. Will report later and welcome any further feedback!
    Current FEP:
    1980 M81 McLaren Carb Turbo 2.3T #003P ... IT'S ALIVE after a 22 year slumber thread!

    Past FEP:
    1986 Capri GS 5.0- very missed but in goods hands
    1985 LTD SSP- quick little fox 5.0

  16. #366

    Default

    OK so blew out the lines through a white towel (clean no debris) and removed the feed line from the tank. Here is what we found

    In-tank fuel filter from the end of the metal feed tube:



    Shots of inside of tank. Looks pretty good to me but some sediment. Nothing significant IMHO that was causing a restriction that I can see. What do you think?



    Relocated my under-hood clear filter to just after tank since I reinstalled the feed unit without the tank filter. I want to see if we pick up the sediment from the bottom of the tank and catch it here before it gets to the fuel pump. We drove for 5 minutes and no stalling but filter looked quite low an flow at idle seemed light.


    I'm pretty low on gas so will pick up 2 gallons tomorrow and see if we can get that filter full up. Would you suggest I do anything different? Any feedback is much appreciated and welcome!
    Last edited by m81mclaren; 12-30-2018 at 10:00 PM.
    Current FEP:
    1980 M81 McLaren Carb Turbo 2.3T #003P ... IT'S ALIVE after a 22 year slumber thread!

    Past FEP:
    1986 Capri GS 5.0- very missed but in goods hands
    1985 LTD SSP- quick little fox 5.0

  17. #367
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,850

    Default

    Looks like good plans and ideas. Work from source first (tank).
    Never thought about doing that and won't forget the trick!
    Process of elimination. They always say change only one thing at a time when trying to pinpoint something.
    At least the car is running long enough to narrow down things and have eliminated suspected items.
    Getting steady fuel flow is priority now.

    Those clear filters are handy, eh? Observation windows.
    Heck could temporarily add a few more here and there. Checkpoints.

    Tank inside looks ok. No plywood or anything floating around.

    Maybe tank level gets too low and pickup sucks air when fuel moves away from pickup (g-force).
    Then sucks air and stalls the engine. Then air eventually works its way out. Line refills by siphon.
    I would feel good with at least 1/4 tank to be sure. Keeps the pickup submerged.
    A little fresh gas won't hurt.

    Try temp pinching off the fuel return line back there too, or temp remove it and cap off ends.
    Pinching off hose with small quick clamp or vice grips works. Doesn't take much.
    Keeps the fuel pump from bleeding off any fuel pressure back into the tank.

  18. #368
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,850

    Default

    Thinking now, never see those filters filled solid with fuel when engine is idling.
    At least at the carb. Fills up when driving?
    Does empty out overnight like the pic.
    Haven't driven car in days. Will check filter tomorrow.
    Last edited by gr79; 12-30-2018 at 10:55 PM.

  19. #369
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,850

    Default

    Tricky how much fuel to add to tank in case the pickup assy has to be removed again.
    Fuel gushing out....

  20. #370

    Default

    Thanks GR yes awesome suggestion to add it in! Normally my clear filter was 1/2 to 2/3 full as indicated last page after sitting 3 days. My initial stalling issue after getting new tires had the filter about halfway full and never empty like it has been the last month of so. Thatís why previously it seemed more electrical in nature and possibly heat related which was the classic symptom of the ignition module failure. While there it made sense to do the dizzy, fuel pump and coil and now good to know those are working well. Does running multiple filters have the potential to constrain flow? I was hesitant to add much more fuel in case it was a bad idea to remove that in tank filter and needed to add a new one in. Yeah I got an arm full of gas and filled 2/3 of my oil drain pan up in the waterfall! I wonder if a larger sock style in tank filter would be a better idea. I agree itís possible I need 1/4 tank or more to simply rule out that I was just low on gas! When I removed the lines at the pump I got about 1/2 quart of fuel. When we blew out the lines about another cup came out of each line. Thatís all I can think of for now. Icing my back but holding up ok thankfully. I really want to get to tuning vs. diagnosing fueling problems!!
    Last edited by m81mclaren; 12-30-2018 at 11:21 PM.
    Current FEP:
    1980 M81 McLaren Carb Turbo 2.3T #003P ... IT'S ALIVE after a 22 year slumber thread!

    Past FEP:
    1986 Capri GS 5.0- very missed but in goods hands
    1985 LTD SSP- quick little fox 5.0

  21. #371

    Default

    Is there anything in the tank baffling it and keeping fuel near the pickup?

    Is the pickup suctioning to the bottom of the tank be being too deep? What about sucking air being too high?


    Brainstorming ..... Is it a fuel tank/pickup problem at all? why couldn’t you make up a fuel bladder and hooking it to the pump directly and see how it acts?

    Or put a wideband on and see where you are when it’s cutting out??

    what if something is causing an air inlet or exhaust restriction and going uber out of range for an air/fuel mixture? Dump valve ..... boost just keeps slowly building until it leans out. Would explain the blown head gasket it had

    process of elimination is what I’d suggest

  22. #372
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,850

    Default

    Actually, this is part of tuning. Insuring max fuel flow to engine. Tuning and repairs. Fine tuning later.

    Yah gas on the arm, and down to shirt....hard to get the smell out even when its evaporated out.
    Lingers even after washing.

    Multiple filters are overkill. Mine runs fine with only the clear one at carb. Suggested that only as radical diagnostic setup.
    Even when filter is apparently not full at idle, the carb gets gas somehow.
    Maybe float acts faster than eye can see and lets tiny bursts of gas in. Does shake around in the filter when running.

    My tank has the mesh on the pickup. After 40 years, nothing was caught in the mesh.
    Maybe something could blow in there while filling up at station on windy day. Some freak thing.
    When one turns their back to hang up nozzle. Piece of leaf, tiny bit of paper. And people lose gas caps...
    We take car of our cars, keep tank clean. but Ford realizes some will not and need a sock. Like baja or sabotage of tank.
    Rusty tanks, that sort of thing. Large debris. Trash. Plastic bags.
    To protect the fuel pump. As much as we drive them, prob can go sock less. But is good insurance.
    A google search says putting a filter right were you did back there does the same thing.

    Maybe run something into the pickup tube itself like a thick wire make sure its completely open.
    Although the M81 is like a race car, did not see tank baffles in the pics.

    I drain tank by pinching off fuel line at the tank, disconnecting the fuel line, then placing the hose in a large gas can.
    Can control flow by pinching off fuel line to get another gas can. Did this replacing the old tank (full).
    Last edited by gr79; 12-31-2018 at 02:40 AM.

  23. #373

    Default

    Wonder if the lack of baffles combined with low fuel levels is THE issue

  24. #374

    Default

    Good ideas here thanks. Does anyone know if there are factory baffles in these tanks to begin with? Wish I had taken more pics inside the tank to confirm. I was thinking a larger filter sock on the feed might help. I am not certain it is a feed problem. I have a wideband installed but the muffler shop put the bung in the wrong spot so it will not be accurate. Hoped to get the stalling/cut out issue issue solved so I can drive it to the muffler shop to refit the bung then start the tuning process. Itís time for 5-6 gallons of gas and see if the fueling issue goes away.
    Last edited by m81mclaren; 12-31-2018 at 09:11 AM.
    Current FEP:
    1980 M81 McLaren Carb Turbo 2.3T #003P ... IT'S ALIVE after a 22 year slumber thread!

    Past FEP:
    1986 Capri GS 5.0- very missed but in goods hands
    1985 LTD SSP- quick little fox 5.0

  25. #375
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,850

    Default

    just some thinkin
    1 qt fuel in lines = 1/4 gal
    20 mpg/4= 5 miles
    32 oz/4= 8 oz, 5 miles
    + some in fuel bowl. another 4 oz or so
    another 2 miles
    5- 7 miles, then fuel runs out; engine quits?

Page 15 of 19 FirstFirst ... 51314151617 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •