Help with these symptoms- code 25, 26 low idle
09-29-14, 01:22 PM
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Help with these symptoms- code 25, 26 low idle
Hello to everyone. I am new to the forum and I'd really appreciate Ii if someone has experienced the following symptoms and could help me diagnose this problem I am having.
I acquired my 1990 ls400 5 years ago. 74000 miles on the odo and running like a champ except for a check engine light with codes 25 and 26. It ran quite well for a while but eventually it started developing low idle. I figured the check engine had caught up to me, but being a broke college student I didn't do anything about it. Time passed and during winter two years ago I started having this infamous problem of the engine dying up on me without gas. I did some research and decided to try cleaning up the IAC valve; that did the trick for a while but some more problems were to follow. Recently I decided to purchase a k&n air filter; little did I know that those filters tend to trigger the air filter light and in some cases contaminate the air flow sensor. To get rid of that problem I tried using some air flow sensor cleaner without luck. Just recently the real problem began. I started to get really low idle when the engine warms up (around 200 to 250 rpm) and jerking sometimes when doing highway speeds. I figured I'd have the transmission checked as It might be the problem. I had it flushed and the filter replaced. The problem persisted so while doing some research I found out It could be a dirty throttle body of loose vaccum hose somewhere. I took out the throttle body and cleaned it really good and checked for loose veccum hoses. That procedure greatly improved my idle while parking with the engine cold; however, it did not fix the low idle after warmup or the jerking wile driving. After that I decided to clean the egr valve filter and replace the pcv valve as they might also be the culprit. Still no luck...
The problem is now worse than ever. I still get low idle after warmup to the point of stalling and jerking occasionally while driving above 40. I also noticed the power has reduced dramatically over the past month. I figured that the problem might be a misfire but I would like to know if anyone has had this kind of problem and can point me in the right direction.
By the way the engine is in need for a tune up but I do need to manage my budget wisely to get the car running normal in the short term. Any help and suggestions are greatly appreciated.
I acquired my 1990 ls400 5 years ago. 74000 miles on the odo and running like a champ except for a check engine light with codes 25 and 26. It ran quite well for a while but eventually it started developing low idle. I figured the check engine had caught up to me, but being a broke college student I didn't do anything about it. Time passed and during winter two years ago I started having this infamous problem of the engine dying up on me without gas. I did some research and decided to try cleaning up the IAC valve; that did the trick for a while but some more problems were to follow. Recently I decided to purchase a k&n air filter; little did I know that those filters tend to trigger the air filter light and in some cases contaminate the air flow sensor. To get rid of that problem I tried using some air flow sensor cleaner without luck. Just recently the real problem began. I started to get really low idle when the engine warms up (around 200 to 250 rpm) and jerking sometimes when doing highway speeds. I figured I'd have the transmission checked as It might be the problem. I had it flushed and the filter replaced. The problem persisted so while doing some research I found out It could be a dirty throttle body of loose vaccum hose somewhere. I took out the throttle body and cleaned it really good and checked for loose veccum hoses. That procedure greatly improved my idle while parking with the engine cold; however, it did not fix the low idle after warmup or the jerking wile driving. After that I decided to clean the egr valve filter and replace the pcv valve as they might also be the culprit. Still no luck...
The problem is now worse than ever. I still get low idle after warmup to the point of stalling and jerking occasionally while driving above 40. I also noticed the power has reduced dramatically over the past month. I figured that the problem might be a misfire but I would like to know if anyone has had this kind of problem and can point me in the right direction.
By the way the engine is in need for a tune up but I do need to manage my budget wisely to get the car running normal in the short term. Any help and suggestions are greatly appreciated.
Last edited by RA40; 09-29-14 at 07:24 PM. Reason: descriptive title
09-29-14, 01:38 PM
#2
hope you didn't use a chemical cleaner to clean your AFM.
Any Lexus made before 1995 will have a Karmen vortex air meter type MAF, or in this case, AFM. (Air flow meter). If you were to clean the Karmen vortex AFM with CRC MAF cleaner, you will most definitely toast your AFM. The only way you can clean it is...well, you cannot really clean, the best you can do is use compressed air on it.
09-29-14, 01:44 PM
#3
ECU capacitors can cause all kinds of drivability problems, that is the first thing I would check, before throwing money at the engine and transmission. The caps are an age thing not a how many miles thing. I would think high temps and high humidity of Florida wouldn't help them either. There is lots of info on here about them.
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