1979-1993 & 94 Conv [Subscribe to Daily Digest] |
Gents,
unfortunately I'm not that familiar with LH system so I can not comment that method at all or advise on certain wire codes to hook on. Nevertheless, here goes my point (or points, plural):
- each job requires some certain tools: it's hardly possible to do an engine overhaul without at least a torque wrench. Neither you should try working on gearbox without, say, micrometer gauge. So when working with engine management components it's a must to have some special tools and one certain tool is an oscilloscope because it's often not a certain reading (e.g. voltage value) that you should carry about, but it's the speed that this value is achieved and you can not measure this speed with any DC (or AC, whatever) multimeter
- in LH system AMM is a device which measures the air-flow and gives some corresponding voltage output. You can find some AMM that will give you pretty good readings with a certain fixed airflow, but this AMM will be dead. Can can this be? It's all about latency - the time it takes it to achieve a certain value on its output. And the rise-fall times. The same goes for e.g. o2 sensor output. Check the graph below and see the difference between blue and red charts - definitely blue o2 sensor needs to be replaced while red one is quite good. And it's impossible to carry out the same test with simple DC-meter
- yes, an oscilloscope isn't $0.02 device, but neither are your wrenches, gauges and benteley or factory manuals. Nowadays you can find a new suitable (for this kind of work) oscilloscope for less then $100 - it's a bargain comparing to what was available on the market even 10 years ago!
- there're lots of special web sites with sample charts and waveforms for different sensors so even if you're not that good with electronics (and Ari, Hans, Jon or me - we're offline from TSN and can't advise if your reading are good or not) you can compare your reading with reference ones
Bottom line:
- should you want to do some LH troubleshooting then oscilloscope is must-have tool
- the advised approach (twisting AMM adj pot until you see o2 voltage swing when engine is hot and idling) appears to be a good idea, but more details on 2.2-2.4-2.4.2 internals are to be studies first before giving the final approval for this method (e.g. should you shorten TPS sensor or not, what should be the temp sensor readings before you can start this adjustment and so forth)
Good luck,
Zig
posted by 188.134.44...
, Thu, 15 Dec 2011 18:11:26
, Fri, 16 Dec 2011 13:52:17
, Fri, 16 Dec 2011 14:05:23, Fri, 16 Dec 2011 13:14:29, Fri, 16 Dec 2011 09:01:06
, Fri, 16 Dec 2011 05:54:10
, Fri, 16 Dec 2011 03:19:18, Fri, 16 Dec 2011 08:21:17, Fri, 16 Dec 2011 16:50:54, Fri, 16 Dec 2011 08:26:22, Thu, 15 Dec 2011 18:12:47, Thu, 15 Dec 2011 18:24:42, Thu, 15 Dec 2011 18:49:59, Thu, 15 Dec 2011 20:57:08
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