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Engine Specific Info and Questions => IDI Engine => Topic started by: Peter on August 30, 2009, 06:01:45 pm

Title: Car Jerks back & forth..Why ??
Post by: Peter on August 30, 2009, 06:01:45 pm: this is for an '86 turbo ...the jerking only takes place when going up a slight incline or turning a corner, but it does not happen all the time..a lot depends on the position of the throttle pedal...when the jerking begins to take place I can either increase or decrease the pedal position and then the car smoothens out
Title: Re: Car Jerks back & forth..Why ??
Post by: burn_your_money on August 30, 2009, 06:46:55 pm: It sounds like it could be air in the system.

Or, there is a RPM where the spring tension vs the flyweight pressure are in a constant state of unbalance. This would cause the jerking you are describing.

I would check for air, and if you see none, then I would try running some ATF or stanadyne performance formula through the pump.
Title: Re: Car Jerks back & forth..Why ??
Post by: vanbcguy on August 31, 2009, 01:19:43 pm: Are all the bolts there for your IP, specifically the 4th one below the injector lines?
Title: Re: Car Jerks back & forth..Why ??
Post by: rodpaslow on August 31, 2009, 01:58:04 pm: Not say it's not something with the engine, but a few years ago I had a front motor mount that would jerk the car cliimb a hill or something when the car was under stress, but otherwise it was fine...
Title: Re: Car Jerks back & forth..Why ??
Post by: Peter on September 01, 2009, 03:13:24 pm: I will definitely check all of the above ...thanks guys
Title: Re: Car Jerks back & forth..Why ??
Post by: 92-Eco on September 01, 2009, 04:57:41 pm: when i got my car it had a similar problem but it was mostly when letting off the throttle and slowing down while in gear. And it was due to the timing being to retarded? Cant see it jerking while under load but....
Title: Re: Car Jerks back & forth..Why ??
Post by: Peter on September 02, 2009, 05:55:10 pm: I got lucky today..the car would NOT run and when it did, with very low rpm's... large bubbles were showing up in the clear fuel line...a new filter was needed and all is fine again
Title: Re: Car Jerks back & forth..Why ??
Post by: Rabbit on Roids on September 03, 2009, 09:46:30 am: yep, filter got plugged, pump lost prime, car wouldnt run. its amazing what a filter does for these things.