racerdave Posted October 22, 2008 Share Posted October 22, 2008 I have a 91 XE with 300k on the body and 111k on the newer 95 motor. The old motor was drinking oil, powerless and leaking. I also had an issue which I thought was ignition until today. I have been driving it with the new motor for about 3 days now, and after I got home from work (10min drive) I wanted to check the tranny fluid and oil to make sure all was well. After adding a little tranny fluid, I started it up, and it goes to 2k RPM and sputters between 2k and 1k, if I give it any throttle, it sputters and it wont rev over 4k under wide open throttle. I had the same issue with the stock motor. Exhaust is all stock, im starting to think my CAT is plugged up, and when it gets hot it becomes restrictive? Can that happen? Something is wrong, I cant figure it out. The newer motor came with coil, distributor, and engine harness. Could it be my ECU? Any ideas on what to check would be great. Thanks. We dont have emissions here, so I was going to just replace it with a high flow resonator. Link to comment Share on other sites More sharing options...
adamzan Posted October 23, 2008 Share Posted October 23, 2008 Just in case, make sure you didn't jar the throttle cable that's for the cruise. When a shop fixed my dads wiper sheer pin on his r50, they pulled the throttle cable slightly and it would do the same thing... Link to comment Share on other sites More sharing options...
MY1PATH Posted October 23, 2008 Share Posted October 23, 2008 I pulled emissons sys & cabon canister pulled for more working room when I went to my bigger coil (yeh its that big, 55,000v) when I put it back it acted the same way; 1 vaccum line was leaking and the other 2 were mixed up. double checked my vaccum lines, replaced 1 corrected the other 2 and all went to normal. Link to comment Share on other sites More sharing options...
racerdave Posted October 23, 2008 Author Share Posted October 23, 2008 Just in case, make sure you didn't jar the throttle cable that's for the cruise. When a shop fixed my dads wiper sheer pin on his r50, they pulled the throttle cable slightly and it would do the same thing... I pulled emissons sys & cabon canister pulled for more working room when I went to my bigger coil (yeh its that big, 55,000v) when I put it back it acted the same way; 1 vaccum line was leaking and the other 2 were mixed up. double checked my vaccum lines, replaced 1 corrected the other 2 and all went to normal. I will check the throttle cable. But I dont see what that has to do with my problem? Can you explain why this would cause that problem? As far as vacuum lines, the new motor is having the same issue the old one had. I checked the lines on the new motor before I put it in, so that makes me think its nothing on the motor that is giving me trouble but something else. Any more ideas on what it could be? Link to comment Share on other sites More sharing options...
Precise1 Posted October 23, 2008 Share Posted October 23, 2008 I would think a plugged cat is a plugged cat, regardless of the temp. Have you run the ECU codes yet? Sorry, but it's something I have learned to remind people of... B Link to comment Share on other sites More sharing options...
nige Posted October 23, 2008 Share Posted October 23, 2008 yeah, check you vacuum lines for cracks etc. If they are good, try unplugging your o2 sensor by the top left corner of the engine bay if you are standing infront of the truck. Sometimes the sensor dies and makes the truck run like crap. Mine did that and the check engine light wasn't even on when it was doing it. Link to comment Share on other sites More sharing options...
adamzan Posted October 23, 2008 Share Posted October 23, 2008 I will check the throttle cable. But I dont see what that has to do with my problem? Can you explain why this would cause that problem? I don't know why it caused it, but all I know is, it was revving between one and 2 thousand and wouldn't rev up high. As soon as I popped it back into place it ran fine again. Wierd... Link to comment Share on other sites More sharing options...
racerdave Posted October 24, 2008 Author Share Posted October 24, 2008 I don't know why it caused it, but all I know is, it was revving between one and 2 thousand and wouldn't rev up high. As soon as I popped it back into place it ran fine again. Wierd... It is not a limitation in RPM. It is randomly missing so bad that it wont go past 4k under WOT. The throttle cables are fine, nothing wrong there. It idles fine at 750RPM, and drops to about 700RPM when at idle when it misses. Under any throttle, it jumps all over the place... I have not checked the codes yet, I will try to unplug the O2 sensor, and see if thats the issue. I am not getting a CEL yet. I started it up again today, and drove it around the block, it ran fine... Its mind boggling... I have never had this problem with a vehicle that I could not diagnose. Link to comment Share on other sites More sharing options...
adamzan Posted October 24, 2008 Share Posted October 24, 2008 When it does it again, pop the hood and wiggle the mass air flow sensor wiring. A few members here have had that problem. It caused erratic Idle and it would stumble up to 4k and thats it, for me. Link to comment Share on other sites More sharing options...
racerdave Posted October 24, 2008 Author Share Posted October 24, 2008 When it does it again, pop the hood and wiggle the mass air flow sensor wiring. A few members here have had that problem. It caused erratic Idle and it would stumble up to 4k and thats it, for me. I will try that again. I tried that when the old motor was doing this, and it didnt fix the problem. If the MAF sensor is broken, it will not work, correct? Or can it be broken and work off and on? Link to comment Share on other sites More sharing options...
Precise1 Posted October 24, 2008 Share Posted October 24, 2008 My understanding is that the MAF either works or it doesn't. The wiring, however, can be intermittent. B Link to comment Share on other sites More sharing options...
Alkorahil Posted October 25, 2008 Share Posted October 25, 2008 My understanding is that the MAF either works or it doesn't. The wiring, however, can be intermittent. B Yep yep yep. Link to comment Share on other sites More sharing options...
racerdave Posted October 29, 2008 Author Share Posted October 29, 2008 Well its not the MAF sensor, it did it again today, and I played with it, nothing changed. I drove it 20 miles, let it sit for 10min, and went to pull it in the shop and it ran like crap, randomly missing and sputtering. After limping it in the shop I unloaded the rear end I plan on installing soon, and let it sit for about an hour. It cooled off, I started it up to go home, and it ran fine all the way home. Im going to buy a new oxygen sensor tomorrow and install it over the weekend, along with a new brake master cyl, and 4.6 rear end with disk brakes.. If I cant narrow down the issue by replacing common parts I am going to take it in and get it diagnosed. Link to comment Share on other sites More sharing options...
edicer2 Posted October 29, 2008 Share Posted October 29, 2008 i didnt feel like reading everyones post cuz its late but i had a problem very simular and i had to wiggle a wire around by my air filter. its a little plug that sticks up and looks like the hood is close to hitting it. I too kit off and cleaned it up and then reconnected it and ran great ever since Link to comment Share on other sites More sharing options...
nige Posted October 29, 2008 Share Posted October 29, 2008 Im going to buy a new oxygen sensor tomorrow and install it over the weekend, did you unplug the sensor and try it without yet? It's an easy test to cancel out the possiblilty of the 02 sensor screwing up the truck. I would check that before i go spending 75 bucks on a new sensor only to find out that's not what was wrong with it. Link to comment Share on other sites More sharing options...
Kingman Posted October 29, 2008 Share Posted October 29, 2008 (edited) The revving problem is the same thing mine had when the coolant temp sensor went out... hit the gas, and the ECU would dump a ton of gas into it and flood it out, so it sputters and what not. It was also intermittent like that, cut power to it and it worked fine the next time I drove the truck. Actually, what yours is doing is EXACTLY what mine was doing just before the sensor totally took a crap on the way to school a week later. Just a thought. Edited October 29, 2008 by kingman92010 Link to comment Share on other sites More sharing options...
racerdave Posted October 31, 2008 Author Share Posted October 31, 2008 did you unplug the sensor and try it without yet? It's an easy test to cancel out the possiblilty of the 02 sensor screwing up the truck. I would check that before i go spending 75 bucks on a new sensor only to find out that's not what was wrong with it. 75$?! I bought one for 35$, and it came with a new plug and everything... Im going to replace it this weekend and see if it helps anything. The revving problem is the same thing mine had when the coolant temp sensor went out... hit the gas, and the ECU would dump a ton of gas into it and flood it out, so it sputters and what not. It was also intermittent like that, cut power to it and it worked fine the next time I drove the truck. Actually, what yours is doing is EXACTLY what mine was doing just before the sensor totally took a crap on the way to school a week later. Just a thought. But the sensor is from the new motor, same problem, different sensor? I will have to try to unplug the sensor and see if it makes a difference in how it runs. Thanks for all the tips, ill post up some results after the weekend when I get a chance to work on it. Link to comment Share on other sites More sharing options...
Kingman Posted October 31, 2008 Share Posted October 31, 2008 75$?! I bought one for 35$, and it came with a new plug and everything... Im going to replace it this weekend and see if it helps anything.But the sensor is from the new motor, same problem, different sensor? I will have to try to unplug the sensor and see if it makes a difference in how it runs. Thanks for all the tips, ill post up some results after the weekend when I get a chance to work on it. I highly doubt it's the same problem as you have, just thought it was interesting that ours shared the same signs and issues, just different causes Link to comment Share on other sites More sharing options...
wheel366 Posted November 1, 2008 Share Posted November 1, 2008 I have a problem with misfiring. It is similar to yours but not the same. I have no problems reving over 4k. Mine sputters when I first start it, a few seconds later it is perfect then give it a minute and I start getting the misfires. It doesn't affect drivability but it is anoying as @!*% and no-one can figure it out. I have had the problem since I got my new engine but I did a few mods when I got the engine. The old engine never ran with the headers so I am not sure if they are making it worse. I do know that when you introduce some gas (gas form, not liquid) into the air box it gets much better so I am getting to much air and not enough fuel. My guess is that the injectors are not supllying enough fuel. It could be that they are maxed out and the ECU can not compensate or I have problems with the injectors. Or maybe the fuel rail. When I got the new engine they did not test the injectors, they just inspected them. I have new O2 sensors already, a new CAT, etc... and I still continue to have the problem. It is to the point where I can not afford to put any more money into the vehicle at the moment. I do have some clunks that I need fixed but that is it. Link to comment Share on other sites More sharing options...
racerdave Posted November 1, 2008 Author Share Posted November 1, 2008 Ok Link to comment Share on other sites More sharing options...
racerdave Posted November 5, 2008 Author Share Posted November 5, 2008 Well after checking things out, the temp sensor is fine. I checked the ECU and did Modes 1-2 and 3. Mode 1 had no issues. I believe it was mode 2 (mixture) was fine, and Mode 3 tells you if sensors are bad or malfunctioning (this is where it would tell me if my temp sensor was not working). Well the code it gave me was 12 (Mass airflow sensor). Im thinking that would be a good reason for it dumping fuel and missing randomly. Is there a way to test the MAF before I replace it? Link to comment Share on other sites More sharing options...
Indigent Posted November 5, 2008 Share Posted November 5, 2008 (edited) Is there a way to test the MAF before I replace it? If you know anyone else with a pathy you could put it in theirs, lol. I would clean it with MAF cleaner and test the wires first. I have never actually had a MAF go bad, but not to say they don't. I had a problem a few weeks ago where mine was giving me a 12 and not running very good. I just pulled it out and cleaned it up. Also, the way the wiring is routed, it is very prone to breaking. Especially if you don't remove the connector when changing the air filter. Get out the haynes, chilton, or fsm and check those wires. MAFs can be expensive. I would hate to see you buy a new one and have it not fix the problem. hope this helps, indigent. Edited November 5, 2008 by Indigent Link to comment Share on other sites More sharing options...
Precise1 Posted November 6, 2008 Share Posted November 6, 2008 I would clean it with MAF cleaner and test the wires first. Some people have had problems with 'MAF cleaner'. I recommend alcohol, Q-tips and some love. Check your wiring connector, it is a common failure point. To test things, warm up the truck, then wiggle the connector and see if anything changes. If not disconnect it entirely and see if there is any change. Other than that, you need a multi meter wo check the wiring/connections. B Link to comment Share on other sites More sharing options...
racerdave Posted November 23, 2008 Author Share Posted November 23, 2008 Well to update.... Since the weather has been colder it runs fine... Very strange. Even after I shut it off and start it up (when its still warm) it runs fine. I have had it miss after just starting up and its still cold, just a random miss every 5 seconds or so under idle only. After I drive it it goes away. I put my stereo in it, and.... well, I am still trying to figure out the whole factory amp thing... its kind of retarded... Link to comment Share on other sites More sharing options...
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