my truck has a new fuel pump new filter new distributor new plugs new plug wires and i cant get rid if a bog i get when i take off it goes away if i floor it but does it only when i stop and try to take off fuell pressure is good anbd i have a new egr valve and even got rid of the cat please help
2007-01-16 08:17:53 · 7 answers · asked by kevin f 1 in Cars & Transportation ➔ Car Makes ➔ GMC
Sounds like you have already replaced most of the things that are the usual culprits. Do you have any codes in the PCM? Check through that stuff if you do. I would check for any vacuum leaks around the intake area with a spray cleaner that will burn. If the motor revs when spraying around a particular area, you have vacuum leak. The most probable gasket is the TBI to intake gasket, very poor design. Check the timing as a lot of people had no idea of how to set these motors timing as you have to disconnect to PCM to set the timing which sets a code. If all of this stuff is getting you nowhere, I would replace the throttle position sensor. These sensors had an ability to not set codes, but to be shorted in several places which caused what you complain of. Good luck.
2007-01-16 14:14:08 · answer #1 · answered by Deano 7 · 0⤊ 0⤋
That's the problem with throwing money (new everything) at a problem rather than understanding how something works and correcting the defect. Bogging on take off is almost always associated with carburetion. A bad fuel pump will generally show up as an overall poor running engine or an engine that dies frequently. Same for the fuel filter. Distributor, plugs and/or wires being bad are going to result in rough running, hard starting, poor gas mileage, and /or poor acceleration. Try to get a good motors manual and visit your local library to read up on vehicle mechanics. Your librarian can suggest some good basic books.
2007-01-16 11:09:22 · answer #2 · answered by mustanger 5 · 0⤊ 0⤋
A possibility is the spark knock system. Is the engine noisy or do you have an exhaust leak at the engine. Sometimes a noise such as I described can trick the knock sensor into thinking that you have a spark knock condition. This will cause the engine control module to retard the timing. And the result is a hesitation.
If it's not that then double check the ignition timing.
There will be a wire,either on the right side firewall or under the dash on the right side,that you will have to disconnect to put the engine in a base timing mode. Then you can use a timing light to set the timing to 0 degrees before top dead center.
If you set the timing without disconnecting this connector,the timing will be way off.
2007-01-16 09:40:43 · answer #3 · answered by Mr. Badwrench 6 · 0⤊ 0⤋
Its probably the timing set incorrectly. the est bypass conn has to be unplugged to set it.also the fuel pressure needs to be at least 14 lbs to perform right.If this cks out ok then have someone ck the TPS sensor and the MAP sensor for proper read-outs with a scan tool,since they are a very important for the ECM to calculate the right fuel mixture.and spark timing.
2007-01-17 05:58:29 · answer #4 · answered by deltech 4 · 0⤊ 0⤋
check the throttle position senor
2007-01-16 12:52:14 · answer #5 · answered by Anonymous · 0⤊ 0⤋
dirty or bad injectors, take it to autozone they will run a free code check
2007-01-19 05:19:24 · answer #6 · answered by peterosefan1414 3 · 0⤊ 0⤋
sounds like your air/idle sensor or your timing. you could also have a dirty air filter.
2007-01-16 09:01:02 · answer #7 · answered by Good ol boy 2 · 0⤊ 0⤋