1988 honda crx HF gas mileage decreasing - Page 3 - Fuelly Forums

Click here to see important news regarding the aCar App

Reply
 
Thread Tools Display Modes
 
Old 12-05-2012, 08:27 AM   #21
Registered Member
 
Join Date: Nov 2007
Posts: 1,852
Country: United States
Location: north east PA
Well, we all eat a little more during the holidays...


Have you tried replacing the fuel filter? May not play a part, but probably a good idea with old gas that was in there. Test the oxygen sensor, but I'm leaning to the old fuel. A friend once got a car that sat 10 years. It started right up on the old gas in the tank. The gums and resins that had formed in the fuel worked there way into the engine where they eventually caused a bent push rod.

HEET is just ethanol, and already in most gasoline. It won't help any more in dissolving any resins in the fuel than the fresh gas. What fuel injector cleaner was it? Perhaps it contained solvents that had little to no effect on the age degraded solids. If there was an improvement with the premium fuel, it could be because they contained a more effective cleaner for whatever was in the tank.

At this point I don't think draining the tank will help. The old fuel has gone through the engine. Try a different injector cleaner, preferably one labeled a fuel system cleaner. Also add acetone. you should be able to find a 16oz bottle of pure stuff at Walmart or a beauty supply store. Use a funnel with it and have a towel ready in case of drips. It will remove car paint, but is the thinner used for varnish, which may have formed in the old fuel. Isopronal in the form of iso-HEET or 91% rubbing alcohol won't hurt.
__________________

trollbait is offline   Reply With Quote
Old 12-09-2012, 08:36 AM   #22
Registered Member
 
Join Date: Nov 2012
Posts: 9
Country: United States
replaced fuel filter, thermostat and just yesterday it started running rough, like it was missing on a cyclinder. I replaced cap and rotor and sparkplugs, did not help anything, still runs rough. Feels like a dead cyclinder. Could it be injectors? I am stumped as of now.
__________________

88crxhf is offline   Reply With Quote
Old 12-09-2012, 08:49 AM   #23
Registered Member
 
JanGeo's Avatar
 
Join Date: Jan 2006
Posts: 2,444
Country: United States
Location: Tiverton, RI
Send a message via Yahoo to JanGeo
Do not assume the new plugs or wires are not defective as well as a bad cap too! Check by pulling a plug wire out of the cap to see which plug may not be firing or a safer way is to pull the plugs and check them for gas fouling. Double check the firing order of the wires to the plugs and does it use points? Check plug gap as well!
JanGeo is offline   Reply With Quote
Old 12-09-2012, 08:52 AM   #24
Registered Member
 
Join Date: Nov 2012
Posts: 9
Country: United States
I drove up a hill and shifted down, 3000rpm for about 5 minutes going up this hill, ran like crap after that. only around idle speed it misses or feels like a dead cyclinder.
88crxhf is offline   Reply With Quote
Old 12-09-2012, 11:42 AM   #25
Registered Member
 
Join Date: Nov 2012
Posts: 9
Country: United States
I just removed the EGR valve and noticed the diaphram was really easy to push. is this normal? I also noticed the car ran smooth when the EGR was pulled off the intake manifold, but back to the same thing with EGR back on the intake manifold.
88crxhf is offline   Reply With Quote
Old 12-09-2012, 12:44 PM   #26
Registered Member
 
theholycow's Avatar
 
Join Date: Apr 2008
Posts: 6,624
Country: United States
Send a message via ICQ to theholycow Send a message via AIM to theholycow Send a message via MSN to theholycow Send a message via Yahoo to theholycow
Certainly sounds EGR-related. Manual says EGR connects to ported vacuum, not manifold...having it connected to manifold vacuum would definitely explain running bad at idle.

It doesn't say anything about how it should feel when you push it but the test procedure is:
  1. Start engine and allow it to idle.
  2. Disconnect the vacuum hose from the EGR valve and connect a hand vacuum pump to EGR valve.
  3. Apply approximately 150 mm Hg (6 in. Hg) vacuum to EGR valve. Vacuum should remain steady and engine should die. If this occurs the EGR valve is working properly. Remove hand vacuum pump and reconnect the hose, test is complete.
  4. If vacuum does not remain steady and the engine does not die, then replace EGR valve and retest.
  5. Should vacuum remain steady but the engine not die, then remove EGR valve and check for blockage, also check manifold for blockage. Clean and replace as necessary and then repeat test.
__________________
This sig may return, some day.
theholycow is offline   Reply With Quote
Old 12-09-2012, 06:56 PM   #27
Registered Member
 
Join Date: Mar 2012
Posts: 200
Country: United States
Pull and read the plugs is one fouled out? Do a compression test. Start at step 0 don't just try this that and the other. Make sure you are running on all 4 cylinders. If one is low ie 3 are 175 and one is 125 it will run and it will run crappy. No amount of parts will fix that. Always start at the beginning. Test vacuum. Check timing then. You can look at egr and so on. If you have a vacuum leak it will show op with a vacuum test. If one of the plugs is all fouled out or looks diffrent then possibly injector on that cylinder. Just take a step back and find out where the motor is. What condition it's in.
__________________

Rusty94cx is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
My experience with Airtabs JudithGordon Experiments, Modifications and DIY 10 01-13-2019 08:32 AM
Wtb p07 ecu mustninty Wanted to Buy 1 07-05-2012 11:27 AM
97 hx hi milage msweatherhead Introduce Yourself - New member Welcome 1 06-08-2011 11:27 PM
city vs highway via SMS? edhans Fuelly Web Support and Community News 3 05-31-2011 07:58 AM
MPG loss due to supercharger bobc455 General Fuel Topics 18 09-20-2010 12:23 AM

» Fuelly iOS Apps
No Threads to Display.
Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 10:30 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.