darren. Posted October 11, 2015 Share Posted October 11, 2015 1992 Toyota Horizon This RV has been flawless until last week. It starts up fine the first time, but begins to lag when idling. Kinda chugs a bit and then finally dies. Gas tank is full. Air filter is clean. Added some stuff to combat condensation in gas tank. After sitting for a few minutes, it takes a while to start. Keeps turning over and then finally starts. It runs for a bit, but then the chugging/weird idling starts again. It's almost as though it's not getting enough gas? Thoughts? Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 11, 2015 Share Posted October 11, 2015 Check fuel pressure first then go on from there if it's OK.. Quote Link to comment Share on other sites More sharing options...
darren. Posted October 11, 2015 Author Share Posted October 11, 2015 How can I check the fuel pressure? I've been searching like a maniac for a diagram of the engine, but can't find anything. Quote Link to comment Share on other sites More sharing options...
Totem Posted October 12, 2015 Share Posted October 12, 2015 some suspects (not in any particular order): 1.) fuel pump (usually in tank and a %$#@$! to remove replace as you must drop the tank or have floor access through floor down; or a very talented child. 2.) AC compressor failed bearings/stuck clutch can drag a motor so see if you can get the AC out of the equation if your fuel pump is ok. 3.) verify air filter clean 4.) distributor cap and wires , replace with new anyway; cant hurt. cheap. Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted October 12, 2015 Share Posted October 12, 2015 before dropping the tank, if I wanted t check fuel pressure I would check it somewhere easier - like the fuel rail. attached are some pages on the fuel pump from the service manual. ToyotaManual-221-226-fuelPump.pdf Quote Link to comment Share on other sites More sharing options...
zero Posted October 12, 2015 Share Posted October 12, 2015 1992 Toyota Horizon This RV has been flawless until last week. It starts up fine the first time, but begins to lag when idling. Kinda chugs a bit and then finally dies. Gas tank is full. Air filter is clean. Added some stuff to combat condensation in gas tank. After sitting for a few minutes, it takes a while to start. Keeps turning over and then finally starts. It runs for a bit, but then the chugging/weird idling starts again. It's almost as though it's not getting enough gas? Thoughts? Sounds like a situation where a gas screen or filter is partially plugged. When you shut it down and try to restart - enough gas gets through and it runs. But then demand with a running engine is so much - it starves for fuel and peters out. Might be the screen in the fuel tank, also a small one in the injection system - or maybe as simple as your fuel filter (although not so simple to get to and change). Fuel filter would be my first thought IF you've never changed it. Quote Link to comment Share on other sites More sharing options...
Dunce Posted October 14, 2015 Share Posted October 14, 2015 I have had a lot of vague engine issues in my couple years of ownership. Almost all of them start with weird misfiring, long starts, power decrease, and gas mileage reduction. As with most diagnostics, start with the easy to test and cheap to replace and move from there. Big things to check: 1. Spark Plugs, pull 'em out and clean them if need be. Fouled plugs, if not super old, are often signs of bigger issues. 2. Distributor and plug wires. Make sure all the wires are attached snug and making good contact. Things bounce around and move a lot, so if it wasn't on super tight to begin with, these can come loose. 3. Valve Clearance - As the head warms up, it can cause already out of adjustment valves to not open and close properly leading to misfiring and (in my case twice) long starts and poor gas mileage. 4. Timing - When was the last time your timing was checked? There is a pretty large range that wouldn't cause any problems, but if you are out some of these problems can be obvious. At this point, most of the issues have been checked for free and some even fixed without parts and with simple hand tools. 5. Like a lot of the discussion, fuel filter, fuel screen, and fuel pumps can cause a whole lot of these issues. I find that only seldom is the case that the fuel pump is fouled, as these are in-tank and made the last the lifetime (albeit we may be past that) of the vehicle. Definitely replace the fuel filter, this should just be a common maintenance and upkeep thing to replace anyway, but if you haven't done it it is probably about time. This is about the end of my knowledge. I have had a lot of luck with making friends at mechanic shops. A lot of times they have a better ear and eye for these problems than we do since they are working on them all day. If you can take it in, it will definitely save you the hassle of endless trial and error. Most recently my valves were so out after the 1000 mile break in of my newly rebuilt 22re that I was sure the guy at the shop made a critical error. Got 'em back in adjustment, and it was like a new ride. I couldn't believe it, and it only took me about 30 minutes. Quote Link to comment Share on other sites More sharing options...
Skydancer2992 Posted October 16, 2015 Share Posted October 16, 2015 Jumper out your mass air flow sensor and see if the problem goes away. The MAF normally must detect air flow to allow the fuel pump relay to supply power to the fuel pump. The factory service manual will show how to jumper out. Or you can clean the MAF (near your air filter). I use carb cleaner although there are also special MAF cleaners at your preferred parts store. Quote Link to comment Share on other sites More sharing options...
5Toyota Posted October 17, 2015 Share Posted October 17, 2015 maybe the gas filter is easer on the six . because on the 22re it shure is in a stupid place. Quote Link to comment Share on other sites More sharing options...
mustrmrk Posted October 22, 2015 Share Posted October 22, 2015 I've had these same symptoms appear caused by a bad connection to the MAF sensor - after 28 yrs, my connector was worn out and the spring retaining clip was gone - I replaced the cable end and the problems went away. You might also check the air hose that runs from the intake to the MAF / air filter - it that's leaking, the MAF signal will be inaccurate. Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 22, 2015 Share Posted October 22, 2015 The fuel pressure is checked at the fuel rail with a banjo fitting adapter. It should be around 35 PSI. Has the fuel filter ever been changed? They are a right pain to change and is all but invisible so it's very likely it has never been changed. The MAF has no electrical parts that are exposed they are under the black cover on the top of the sensor you can make the pump run by removing the large hose on the MAF intake and opening the air vane with your finger to check fuel pressure. Quote Link to comment Share on other sites More sharing options...
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