Jerks or misfire when driving with ac on at low rpm or idle
#1
Jerks or misfire when driving with ac on at low rpm or idle
Hi guys first off I'm a new member but not new to the site as I've been looking at threads for years. However I recently bought a 1993 del sol s, D15b7 engine manual trans with 296k miles all original.
Problem I'm having is when I have the ac on the car would idle fine Except randomly it would jerk a little and I can see the RPMs jump down for a sec and then back up, even while accelerating it does the jerk or misfire. Only when the ac is on though. I have noticed that with the ac on it hesitate getting off the line when at a red light, I kinda have to add extra gas in order to get off the line with out any problems.
To top it off I've been having the random car won't start that people said they have fixed with a new main relay. My car would be good and then when it doesn't want to start, it will crank but not turn over However the few times that it will turn over and die I quickly give it has for a little bit and then it stays on. Or sometimes if I wait 5 min and leave it alone it will start right up with out any issues. I'm not sure if my fuel pump is bad or if it's the main relay. Bc when I get out of my car I can smell fuel. And yes I have looked underneath the car with a lift and don't see any wet spots.
What I have done to it has been maintenance like
Cleaning iacv
Cleaning fitv
Coolant flush
Right inner and outer tie rods
Right upper control arm
Right lower ball joint
I plan on doing the same to the left when I get some time.
Any help will be appreciated, thanks guys
Problem I'm having is when I have the ac on the car would idle fine Except randomly it would jerk a little and I can see the RPMs jump down for a sec and then back up, even while accelerating it does the jerk or misfire. Only when the ac is on though. I have noticed that with the ac on it hesitate getting off the line when at a red light, I kinda have to add extra gas in order to get off the line with out any problems.
To top it off I've been having the random car won't start that people said they have fixed with a new main relay. My car would be good and then when it doesn't want to start, it will crank but not turn over However the few times that it will turn over and die I quickly give it has for a little bit and then it stays on. Or sometimes if I wait 5 min and leave it alone it will start right up with out any issues. I'm not sure if my fuel pump is bad or if it's the main relay. Bc when I get out of my car I can smell fuel. And yes I have looked underneath the car with a lift and don't see any wet spots.
What I have done to it has been maintenance like
Cleaning iacv
Cleaning fitv
Coolant flush
Right inner and outer tie rods
Right upper control arm
Right lower ball joint
I plan on doing the same to the left when I get some time.
Any help will be appreciated, thanks guys
#2
Old Fart
Join Date: May 2004
Location: kelowna, bc, canada
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Re: Jerks or misfire when driving with ac on at low rpm or idle
I would start with the PGM-Fi Main Relay... PGM-FI Main Relay problems and fixes
It is a very common problem and may solve both/all of yours. 94
It is a very common problem and may solve both/all of yours. 94
#3
Re: Jerks or misfire when driving with ac on at low rpm or idle
Ok cool thanks any tips on where I can get a new one? I only seem to find used ones. Also will other models work or only del sol
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