rpm jumping??

coalminer78

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When I'm driving it will sputter and rpms will jump up and down between 2000 and 4000 rpm. No check engine yet tho. Any ideas?? I've replaced the head gasket and everything above, thermostat, and cam sensor last month or so. All three coils in the last year.
 
how old is the fuel filter?
 
Been over 5 years....took it out today and it ran fine until it warmed up.....rpms started jumping and it was sputtering and after about a mile died
 
so you may have a clogged filter or bad pump, replace the filter and do a fuel pressure test.
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It stopped act up for about 2 days. I still changed the fuel filter and pressure was at 45. Last night it started again. Starting to think its electrical. Lights dimmed a bit when it start bounce up and down rpms. Any other ideas??
 
Have you checked your battery connections both at the battery, the ground and the starter?
 
Check all battery connections and the are tight and clean. Noticed today it only does it after warm up. No check engine light yet. If it was a misfiring cylinder won't the light come on?? Seemed like today it was acting like it was flooding a bit. By the way drove about 4 miles was fine than for the next 5 miles acted up than for about 2 miles it was fine and than started again. This was all at 55 miles per hour and it seemed to keep speed within 5 mph or so. I just wish the check engine light would come on.
 
have you checked fuel pressure regulator vacuum line for gasoline indicating it has failed.
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it's dry but does smell like gasoline? can you try removing it with the engine running?
 
When I unplugged it I heard the suction and it was strong and still could smell some gas. Rpm didn't change.
 
no gas dripped from the pressure regulator after a few minutes?
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Left it off for about 10 minutes and no gas came out. Had the wife take it up to 3000 rpms and hold it and the rpms did not jump around. Think it only does it while drive or maybe didn't because the vacuum was off.
 
Still doing it and getting worse. I notice today it was smoking around the fuel regulator and throttle body. Still trying to find out what is wrong. Will have more time to test stuff saturday. Want to check plugs and wires plus test the tps. I will also check voltage at. battery and see if alternator is charging since the lights are dimming. If anyone has anything else they think maybe the problem let me know. Need it fix asap only way to work which is 14 miles and don't want to bike it when I'm working 12 hour days.
 
what kind of smoke, color, smell? smoking from what source? do you have a coolant leak an oil leak?
 
I'm not sure because it was dark and I only had a flashlight but I would say it was coming from the coolant port on the side of the thermostat housing. The smoke didn't have any smell really.
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Tps tested bad. As I opened the throttle volt went up and down. Replaced it and didn't help. Back to square one. Smoke was a lose coolant hose to the throttle body.
 
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On my 03 my tb was all gummed up and had varnish in and around it. Had to use carb cleaner and steel wool to clean it. Maybe yours is worse and not properly closing all the way?
 
The tps voltage is supposed to go up and down. A bad one will have dead spots while moving.
 
I cleaned the tb about 2 months ago when I put in new head gaskets. Never went as far as using steel wool. It quick getting it off so I will give it a try.
 
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