QuestionQUESTION: 1997 grand voyager 3.3L - Recently on a long hot summer trip, under full load of passengers and luggage and on steep inclines the engine would lose power forcing me to stop. The temp gauge was only slightly above the mid mark so no obvious overheating was indicated. After about 30 min the engine would start and run normally for a while before the problem occurred again. Once through the mountains and on flatter roads the van ran normally. Any advice?
ANSWER: Hi Keith,
It could be an issue with one of the engine control sensors or it might be a 'breathing' problem or a mixture problem.
The engine controller has self-diagnostic capabilities which may have resulted in a fault code being store in the memory. One way to get a code is to use the ignition key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch for either the odometer mileage reading to change to show 4-digit number preceded by a P which would be the codes, or for the check engine light to begin to flash, pause, flash, etc.; then count the number of flashes before each pause and repeat the entire process to be sure of an accurate set of flash counts. Tell me the results and we can go from there. If neither readout appears, then a free code readout via an underdash socket will often be done at an Autozone parts store or for under $40 at a shop. Get the numbers and let me know either way.
The other possibility is that the catalytic converter's honeycomb is off-axis or clogging up such that the high volume of exhaust gas when climbing steeply at wider throttle position is not being efficiently expelled. A muffler shop can measure the backpressure in the exhaust system to check out that possibility.
The fuel pressure may be a bit low as well and that can be measured too and that would cause a too lean mixture under high demand circumstances, but we may get a fault code that points that way.
Roland
---------- FOLLOW-UP ----------
QUESTION: Hi Roland
Thank you for your response. I checked the fault code as requested, using the ignition key and counting the "check engine" flashes. Total flashes counted were 13 as follows: 1 flash then pause, 2 flashes then pause, 5 flashes then pause, 5 flashes then off.Your further comments on the possible causes of ths problem would be appreciated.
AnswerHi Keith,
Those codes are not helpful to the issue. The 12 just means the battery was disconnected recently from the system, which unless that isn't true would not be anything significant. If you don't know of any disconnect, then check your battery clamps.
The 55 means 'end of code readout.
The only possible cause for loss of power under load that I can suggest is that the egr valve may be sticking ajar instead of closing when your throttle is open for more power. That would thin the mixture and cause low power. The valve is located near the throttle body air intake at the end of the engine, mounted in pipe that recirculates exhaust gas from the rear cylider bank exhaust pipe back around to the intake manifold. The exhaust gases have some fumes that can plate out a crud on the valve stem and thus keep it from closing tight when you are at idle. That makes for a too lean mixture so the engine stalls. The valve proper is mounted horizontally with the stem visible in a space between the body of the valve mounted on the pipe and the round top of the valve which is flanged and so if you look carefully you will see a metal rod (stem of the valve) with a slot around its circumference. You can take the tip of flat blade screwdriver and insert it in the slot and then lever the valve back and forth to check if it is moving freely (against spring action in one direction) or not. If it doesn't seem to close easily with the help of the built-in spring, then I would spray the base of the stem with solvent from a pressure can (such as WD-40 or carb cleaner) while moving the stem back and forth. Then see if that solves the issue.
Roland
