New press reg-car won't start

Tiny
NITRONELLY
  • MEMBER
  • 1985 MERCURY TOPAZ
  • 4 CYL
  • 2WD
  • MANUAL
  • 160,000 MILES
1985 merc topaz 2.3 TBI --milage droped from 30 mph to -6 mph --I replaced the fuel filter and the fuel pressure regulator---now the car won't even start---air in the fuel system now?---HELP!---
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Saturday, January 8th, 2011 AT 5:21 AM

10 Replies

Tiny
RASMATAZ
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Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 away from ground-have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if so, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, cap and rotor, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it and keep testing
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Saturday, January 8th, 2011 AT 5:31 AM
Tiny
FIXITMR
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Fuel pump is under back seat in tank. You can hear it humm for a second or 2 when you turn key to 'on' but not start.
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Saturday, January 8th, 2011 AT 7:20 AM
Tiny
NITRONELLY
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IT"S NOT a "SPARK-PROBLEM" or a "FUEL PUMP" problem---Both work just fine---I tried to put the "OLD"-PRESS. REG" back in but I dropped and lost 1 of the 4 screws to hold down the press, reg cover---with out that screw gas sprayed out --so not a fuel problem---I'm in the "Sticks" so it's hard to get another replacement screw on the weekend---time-out till MONDAY---AGAIN IT RAN BEFORE INSTALLING THE NEW PRESS REG and NOT AFTER--so problem is "ONLY" in the TBI.---
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Sunday, January 9th, 2011 AT 4:24 AM
Tiny
FIXITMR
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Hey, I failed to note you had an old TBI! Easiest model to work on! You'll appreciate it when/if you have to change the waterpump. Those darn little screws! Is it cold where your at?
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Sunday, January 9th, 2011 AT 9:44 PM
Tiny
NITRONELLY
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I've replaced the water-pump twice in 20 years (pain in the butt) I'm an old school mech(ya know old style ign. & Carbs) This new stuff takes me a bit if I don't have a book close by(in the sticks remember)--The fuel press reg. Keeps a constant press. At the TBI injector(RIGHT?)And when press gets extreme it opens to bypass(RIGHT?)The old diaphram was/is easy to move, and the new one (FROM NAPA AUTO) is real stiff.---Checked spark plugs after new one installed (drowning in gas)maybe explains bucking and no start. Defictive new REG(diafhram/too stiff) FUEL BYPASSNOT OPENING WHEN NEEDED, maybe bypass system plugged(still it ran with old press.-Reg. And not the new one)The old plugs (spark) real tight and I broke one off-another 32 mile trip to the auto parts store, when I can get a ride---Also the "IDLE SPEED MOTOR" is defective (runs alot and sounds real noisey and nasty, it's 25 years old old and tired and costs $100.00)If I had more money I'd dig a hole and burythis car, but now not an option---Thank-you for any help---
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Monday, January 10th, 2011 AT 3:11 AM
Tiny
FIXITMR
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The other nice thing about TBI is you can watch the injector working to help diagnos any fuel related problems. And compared to multiport imjection which is what they changed over to later changing the water pump is a breeze on yours. You really have the next best thing to carb and points system. A simple computer run system for efficiency and pollution control. Granted your location does not favor lack of knowledge or parts replacement. But you do have computer access to the world to study up if you care to. Some of it free.

When you get the old diaphragm back in and it's running again we can try to diagnose your original problem. I dont recall off hand where the MAP sensor is for that system which is the most influential sensor for fuel supply/mixture. I do have a book(crappy haynes) for this car so i'm looking it up. No luck so far. And they did make a carb version in 84. You missed it by 1 year! Although pollution controlled carbs aint much fun either.
Let's see, says fuel pressure is regulated at 39lbs. The injector is pulse TIME modulated having a fixed orifice. And dont forget the TPS. It's checkable with a multimeter as it functions like a rheostat. You can disconnect EGR to see if that's a problem. Just take off vacuum hose. Another good point is this engine has a fool proof timing chain that i've never heard of it going bad. The trans is old school and pretty reliable. I had 300,000 on 1 in a car i'm now using for parts for the 2 I have running. My boondocks junkyard(15m away) still has some of these cars!
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Monday, January 10th, 2011 AT 5:51 PM
Tiny
NITRONELLY
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I put my non-opp truck back on the road for parts runs, need to take a day to a few off for, parts run, pay bills, and rest my brain.---After pulling a spark plug the other nite, I'm running with the idea the "NEW PRESSURE REG." Is defective because /w the old old one the car at least ran, NOT WITH THE NEW ONE, the plug I pulled is soaked in gas and my garage reakes in gas fuems---telling me that the PRESS.-REG. Is not by passing excess fuel---NEW QUESTION---can I put a "low-pressure" air line/blow to the TBI to the gas tank return line/w out causing more prob---Maybe the TBI fuel return-line is cloged or blocked?---Thank-you much for the input---nitronelly---I used to be real good on the old cars making them run for friends---These new things are a renewed chalange---a little rusty-been pounding/shooting nails for 23 years---Cleaner-Hands-Less-Headache---"LOL"---Thanks-N---
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Tuesday, January 11th, 2011 AT 5:15 AM
Tiny
FIXITMR
  • MEMBER
I just revisited another thread on a similar year tempo that turned out to be the TPS. I mean look how old the car is? It cost $25 he said. And he had the rattling IAC and changed it to no avail. It's supposed to rattle going thru it's self test? I know of at least 2 instances now where the rattling IAC and changeout had no effect on problems. Personally I hate working on house stuff/wood! I'd rather have greasy hands and scraped knucles than sawdust in the eye/nose/splinters in the hands/smashed thumbs! Oops, forgot the occasional saw gash! Have fun.
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Tuesday, January 11th, 2011 AT 8:34 AM
Tiny
NITRONELLY
  • MEMBER
YOU--- didn't ansewer my question---CAN I CHECK THE FUEL RETURN LINE < FROM THE TBI TO THE "GAS-TANK"-BY BLOWING HIGH OR LOW PRESSURE AIR FROM THE TBI RETURN LINE TO THE TANK?---I MAY HAVE SOME KIND OF "BLOCK" IN THAT LINE---CAUSING "ALL" MY PROBLEMS---PLEASE REPLY TO MY "RETURN-LINE"--QUESTION---
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Friday, January 14th, 2011 AT 8:58 AM
Tiny
FIXITMR
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Yah, you can blow thru it. Another idea would be to just disconnect it and catch the results in a container?
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Sunday, January 16th, 2011 AT 6:17 AM

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