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The text above is a follow-up to ...
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I, have rebuilt my 4G63 engine, thank to you a lot, it is quite good except for the hesitation on 2nd gear, it feels that there is a power lag between initial acceleration and final acceleration on 2nd gear, I checked the advance timings some time the trouble goes away but then it returns, when I check my timing setting they are Okay and did not move, I notice however that the movement of the advancer which is controlled by the vacuum advancer has the same lag from its initial setting on idle, it take a while up before it pulls on the vacuum advancer with respect to throttle action, in relation to this, my vacuum gauge shows 15 Inch Hg on idle, and when I start to open up the throttle the vacuum drops to about 10 and then immediately goes up to about 28, as it drops the hesitation is apparent, I Have checked for vacuum leaks and intake manifold and I found none,I checked the enrichment circuit for the carburetor, it is giving off a squirt of gas as the lever starts to move,I do not find any valve related problems, my compression is 127 to 129 Psi on all four.
could you point me to right direction of diagnosing this problem, and recommend a solution.
Thank you very much
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Cezar: I would say whatever that is building the pressure up as in the vacuum, is not doing it's job. In that you say it starts out or when you open up the throttle action, the vacuum drops but then goes up to 28. You are sure you do not have a vacuum leak, have you listened to all the hoses and the such. Sometimes a vacuum leak can be very, very small. But yet if it drops to 10 and then goes up to 28. Something is causing the drop only to kick it up back up. What of the computer of your car, it sets the mix of the air and the fuel. I know the computers of your car is not super strong but yet, something has to be pulling the engine down and then kicking it back up. What of your throttle is it a smooth movement or does it kind of jump? Maybe a good cleaning of the throttle, there could be a throttle sensor that might be causing you troubles. I can not remember how old this engine is. You could get a voltmeter, test the engine with it as it might show you, the problem with this. As it might be do to the voltage. I do hope this helps and good luck!
My engine is an old engine, it was built during the early eighties, it is a 4G63B by mitsubishi, it has no electronics on it, altough it is the distant relative of the 4G63 evolution VIII,the diffrence between the two are the electronics and the cylinder head, the rest of the mechanical are basicaly the same.
this partiular engine is giving me weird kinks, that is why I am having difficulty in dianosing the problem.
I have checked all possible sources of leaks, the vacumm guage needle is steady during idling, and could go as 29 inHg, in the low end of the trottle,that seems okey, but what really bothers me is the hesitation, which seems to be eratic, raising the idling RPM solves the problem or advancing the firing by about 20° BTC solves the problem but these solution does not solve the underlaying problem, what causes the hesitation when everything is set to normal like RPM 800, and Advance of 8°BTC ( is about the max for idling) otherwise hard starting and ping will result, that is the reason I am consulting you about this particular problem I seem to run out of option and posibilities as to the cause of this problem.
any help is greatly appriciated.
AnswerCezar: The only reason I told you about my busy week, is I felt bad for making your wait so long for an answer. You were not a bother to me, I enjoy trying to answer people's questions but feel badly when I can not answer them. So I did look around and talked to people. Just did not get any help. So I am sorry about that. Thank you for the nice report back. I wish I could have helped you more. Linda
