I have a 1990 accord dx 5 speed and i just had the timing and valves adjusted and im still have a bad shake and idle problem. The things I have done is new plugs, wires, cap, rotor, vss, cleaned the egr ports and valve, cleaned the iac and fitv. i am absolutely stumped. when i pump the brake i noticed the rpms will raise to 1000 rpms and then drop all the way down to under 500 and almost die but then go right back to 750 rpms. I just need some help

 

If it's related to the brakes it's going to be a bad brake booster or brake booster hose. With the engine running, disconnect the hose from the booster and put your finger over the end of the hose. If you have vacuum (suction) then the hose is good.

Other than that, bad motor mounts can make the car shake really bad.

 

Im cant tell if you mean the shake is related to the idle or if your having two separate problems, but if the shaking is unrelated to the idle id check your half shafts, steering system (pump, rack and pinion and lines), ball joints, bearings and your tie rods. I had a similar problem with my 94 accord and replaced all that to find it was my rack and pinion fixed the shaking.

 

It only shakes when i am stopped at a stop light or sitting in neutral.

 

Sometimes cleaning the iacv isn't enough. The seals inside get worn over time and it needs to be replaced.

Check your base idle first. If it is 500-600 then it's likely your iacv is bad. You can also test across the iacv pins. It should be 8-15 ohms, usually 12 ohms.

Make sure the car is completely warmed up. It's possible the fitv needs to be tightened down.

 

I had a 90 dx that spewed loads of white smoke out the tailpipe that smelled like cat urine. Come to find out, the brake booster was bad, which caused fluid to travel into the vacuum line and into the motor. I wonder if this might be causing your issue? Have you checked your brake fluid level? Have you had to add more fluid on occasion? (Booster fills up with fluid when the seal goes bad).

 

no nothing like that and now in the mornings or when the car sits for awhile when i back up the car wants to die, but does not and then just acts like i mentioned before.

 

Have you checked the igniter?

 

no i have not. How do i check that?

 

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