Folks,
This is my first time posting, but I've been lurking for a few years. I haven't had to post since there is so much good info on this site. This time I am stumped and I'm hoping that you guys can help me out. At best I am a shade tree mechanic and at worst a parts replacer so all suggestions are appreciated.
I have a '72 FJ40 with a rebuilt 2f engine (I think it is a 1984 with about 25,000 on the rebuild). It is de-smogged with a Trollhole Carb and HEI Dizzy distributor. Other than this some of the highlights are FJ60 power steering system, 5 Speed transmission, Old Man Emu 4 inch lift on 33's, power brakes with Toyota disks up front, 4 Core Radiator with all new hoses, and a few rust issues.
About 3 weeks ago it started began idling rough. Prior to this, the vehicle sat for about 5 months while I was on a trip. When I returned I put some fuel cleaner in the gas tank to get me by until I filled up again and did a tune-up (new plugs, oil change, etc). During this and the next tank of gas the engine ran better than it ever has (should of known this was a bad sign). Then it started idling rough. Now it idles as if the engine is missing. When I hook my timing light up I get a solid even pulse and then it pauses. The pause coincides with the rough idle and drop in vacuum pressure. Then the engine backfires out of the exhaust, recovers, and the sequence begins again.
I have a vacuum reading of 14-15, which I think is a little low. I do not have tach but I have the rpms set as low as I can and still keep the engine running. The vacuum gauge is hooked up to the hose coming from the intake manifold to the brake booster.
My compression numbers are:
1 2 3 4 5 6
Dry 145 135 125 140 140 145
Wet 150 145 135 150 140 155
In an attempt to correct the idle issue I have done the following (all of which were recommended to other members that have had similar issues).
-Replaced the vacuum lines.
-Replaced the PCV valve.
-Check for vacuum leaks with carb cleaner. Found nothing. Check with a home made smoke machine (cigar smoke into the vacuum line going to the brake booster). Found nothing. Then I pressured the engine with 2-4 psi of air and blew dry ice smoke over the engine. Still found nothing. I know none of these test are 100% but I really don't want to replace the manifold gasket unless I really have to.
-Checked the idle solenoid. It clicks when I turn the key. The engine also dies when I unplug it.
Rebuilt the carb using the FSM and Pin Heads videos (thanks for those, they saved me a lot of time). I dipped the carb, sprayed carb cleaner in all the holes, and blew out with air. The fuel level is half way up in the sighting glass and I have the mixture screw 2 turns out. I also have good fuel flow when I push the gas pedal.
None of these steps have helped the idling problem. I removed the idle solenoid a second time and sprayed carb cleaner through the port followed by compressed air. I removed the plugs, cleaned them, and checked the gaps. Adjusting the timing and the mixture screw on the carb does not improve the idling. Before I replace the manifold gasket I was hoping someone could offer some suggestions. I appreciate the help. If anyone needs more info please let me know.
This is my first time posting, but I've been lurking for a few years. I haven't had to post since there is so much good info on this site. This time I am stumped and I'm hoping that you guys can help me out. At best I am a shade tree mechanic and at worst a parts replacer so all suggestions are appreciated.
I have a '72 FJ40 with a rebuilt 2f engine (I think it is a 1984 with about 25,000 on the rebuild). It is de-smogged with a Trollhole Carb and HEI Dizzy distributor. Other than this some of the highlights are FJ60 power steering system, 5 Speed transmission, Old Man Emu 4 inch lift on 33's, power brakes with Toyota disks up front, 4 Core Radiator with all new hoses, and a few rust issues.
About 3 weeks ago it started began idling rough. Prior to this, the vehicle sat for about 5 months while I was on a trip. When I returned I put some fuel cleaner in the gas tank to get me by until I filled up again and did a tune-up (new plugs, oil change, etc). During this and the next tank of gas the engine ran better than it ever has (should of known this was a bad sign). Then it started idling rough. Now it idles as if the engine is missing. When I hook my timing light up I get a solid even pulse and then it pauses. The pause coincides with the rough idle and drop in vacuum pressure. Then the engine backfires out of the exhaust, recovers, and the sequence begins again.
I have a vacuum reading of 14-15, which I think is a little low. I do not have tach but I have the rpms set as low as I can and still keep the engine running. The vacuum gauge is hooked up to the hose coming from the intake manifold to the brake booster.
My compression numbers are:
1 2 3 4 5 6
Dry 145 135 125 140 140 145
Wet 150 145 135 150 140 155
In an attempt to correct the idle issue I have done the following (all of which were recommended to other members that have had similar issues).
-Replaced the vacuum lines.
-Replaced the PCV valve.
-Check for vacuum leaks with carb cleaner. Found nothing. Check with a home made smoke machine (cigar smoke into the vacuum line going to the brake booster). Found nothing. Then I pressured the engine with 2-4 psi of air and blew dry ice smoke over the engine. Still found nothing. I know none of these test are 100% but I really don't want to replace the manifold gasket unless I really have to.
-Checked the idle solenoid. It clicks when I turn the key. The engine also dies when I unplug it.
Rebuilt the carb using the FSM and Pin Heads videos (thanks for those, they saved me a lot of time). I dipped the carb, sprayed carb cleaner in all the holes, and blew out with air. The fuel level is half way up in the sighting glass and I have the mixture screw 2 turns out. I also have good fuel flow when I push the gas pedal.
None of these steps have helped the idling problem. I removed the idle solenoid a second time and sprayed carb cleaner through the port followed by compressed air. I removed the plugs, cleaned them, and checked the gaps. Adjusting the timing and the mixture screw on the carb does not improve the idling. Before I replace the manifold gasket I was hoping someone could offer some suggestions. I appreciate the help. If anyone needs more info please let me know.
