Low RPM and rough idle
#1
Senior Member
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Thread Starter
Low RPM and rough idle
HI all,
I had an issue several months ago where I blew out my UIM on my 92 bonnie.
I've replaced the complete UIM and replaced the gaskets on the LIM. since then, when I stat her up, she'* running at a very low RPM. The engine spins faster with the Starter than just the the engine.
On taking her for a test spin, I've noticed she runs much hotter. Just under the split between 200 and 280. Say 240 ish. I am running 100% water with some flush at the moment so that may be related, but I wanted to spell everything out.
Anybody run into this?
Thanks
G
I had an issue several months ago where I blew out my UIM on my 92 bonnie.
I've replaced the complete UIM and replaced the gaskets on the LIM. since then, when I stat her up, she'* running at a very low RPM. The engine spins faster with the Starter than just the the engine.
On taking her for a test spin, I've noticed she runs much hotter. Just under the split between 200 and 280. Say 240 ish. I am running 100% water with some flush at the moment so that may be related, but I wanted to spell everything out.
Anybody run into this?
Thanks
G
#5
Senior Member
True Car Nut
i dont think it has anything to do with the idle. the fans may work properly once you change back to regular coolant and bleed the air out
#6
Senior Member
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Thread Starter
Thx JW,
BTW, I cleaned out the IAC, it ran fine for about 5 minutes while it was "ice" cold but as soon as I hit the first stop light (about 1 min), she started to shake again.
Any other ideas?
Thanks
BTW, I cleaned out the IAC, it ran fine for about 5 minutes while it was "ice" cold but as soon as I hit the first stop light (about 1 min), she started to shake again.
Any other ideas?
Thanks
#9
Senior Member
OK, you come to a stop, and the idle drops......if it drops below 600 rpms, the idle will get rough....if you lightly step on the gas to raise the rpms above 600-700, does the roughness go away?
As JW said, putting the proper mix of coolant, a new therm, and properly bleeding the system may take care of the temp problem.....
Have you checked for codes, doing the flash procedure or using a code reader/scan tool?
When you had the top of the engine off, that was a good time to thoroughly clean the throttle plate and bore......
Could be an IAC or harness problem, especially if slightly raising rpms with gas pedal clears up the roughness.....
When car runs rough, shut off and disconnect the MAF sensor and see if car runs better......
Make sure air filter and box is clear.....
Check fuel pressure....last time fuel filter replaced?
If coolant got into the exhaust, it could have contaminated the O2 sensor....
As JW said, putting the proper mix of coolant, a new therm, and properly bleeding the system may take care of the temp problem.....
Have you checked for codes, doing the flash procedure or using a code reader/scan tool?
When you had the top of the engine off, that was a good time to thoroughly clean the throttle plate and bore......
Could be an IAC or harness problem, especially if slightly raising rpms with gas pedal clears up the roughness.....
When car runs rough, shut off and disconnect the MAF sensor and see if car runs better......
Make sure air filter and box is clear.....
Check fuel pressure....last time fuel filter replaced?
If coolant got into the exhaust, it could have contaminated the O2 sensor....
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WilliamE (07-18-2014)
#10
Senior Member
True Car Nut
in addition to the things gus mentioned, i have had a couple times where the coil post started getting corroded, it will look dull instead of shiny. and it it will run kinda poor at idle or in fourth locked tq at low rpm like 40-50mph. if you dont put grease on the wires or plugs when replacing them it can run like that too