I have OBDll analizer. Will that work on OBDl?
You don’t even know who you are replying to, VDCdriver had not replied anything to you except to object to your language. I am the only one who said anything you could have construed as insulting, but I did not resort to unnecessary vulgarity.
It is not that I am shocked by it, I was a truck driver for 40 years but I find it’s use distasteful and even cowardly unless you are talking face to face.
We apparently have different opinions about what constitutes a competent mechanic. We can’t run diagnostics on your truck because we don’t have access to it. You do.
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Not 100% sure, but I don’t think so. But on GM OBD1, you can get codes by jumpering a couple of terminals and turning the key to on (but not starting the engine) The check engine light will flash a certain number of times, then pause, then flash again. It’ll flash a numeric two digit code like “32”. The only code I remember is the first code it always gives, which is code 12, which just means the system is functional. There are YouTube vids on it and such, I’m probably not the best at explaining it. The codes often don’t give you a ton of info on exactly what’s wrong, but it might give you an idea on a starting point, if a sensor is the issue. Changing the filter won’t hurt, but if it runs fine except for slow starting, I doubt it’s the problem.
I am aware of the procedure. Had actually forget about it and didn’t know if it would work on this vehicle. I’ve got my work cut out on diagnosis for sure. Process of elimination. Thanks for the input
Well when it gets 20 below out, lots of problems can develop that wouldn’t at 20 above. I’d do a fuel pressure test if you ever get it running but yeah I suppose the contacts in the actual ignition switch could be a little sluggish at that temp if they are worn some. Still if the lights do go on and the fuel pump turns on, I would think that would do it. Again, plugs, wires, ground wire connections etc. At low temps everything needs to be in good condition.
Unlikely. As posted above, OBD I diagnostic codes are usually read out using the manufacturer’s procedure without needing a separate analyzer. Done by setting a test mode, then looking for blinking lights in a certain sequence to identify the code number.
You’re mostly right . . .
However, there were at least a few manufacturers who had extremely capable OBD1 scan tools, which gave you live data and functional tests, in addition to code retrieval and code clearing
So, just because a vehicle is OBD1 doesn’t mean the pcm isn’t capable of displaying some very useful data
I was never able to find anyone that still had a scanner to read OBD1 data. But I only tried a couple of local parts chain stores.
It acts like it doesn’t even get ignition initially, I have to play with the accelerator to get it to fire, idle air temp sensor? This is a simple fix. I did find a 454 group on FB…maybe I can find the answer there
Could be coolant temp sensor or idle air control valve. There are ways to test them with a voltmeter, but I don’t recall exactly how. I’d hate to just buy sensors without knowing for certain.
It just has a long crank time, right? But runs ok?
Coolant temperature sensors are almost always ntc . . . meaning sky high resistance cold, gradually dropping to low resistance hot
You test them with an ohmmeter, which has a chart and/or graph, showing you what resistance you’re supposed to measure at a given temperature
as for iac, there are so many different kinds, offhand I don’t recall the proper way to test the one on a 1994 GM big block with tbi
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Haha! That’ll work. Wouldn’t mind one of those myself.
But it’d be badass with a TBI 454 in it lol.
They must have made a pre-computer 454
Lol, that they did. Pops had a Brown 73 Caprice with a 454 and 4 barrel carb. Was our family car until about 1989.
Well, There I go
I’ve just been advised it’s likely as simple as a tune up. Cap Rotor Plugs Wires
Yeah, maybe. If it hasn’t been done in a while, can’t hurt for sure.
I think you mentioned it has a misfire anyway, so the tuneup could definitely help there.
It was the distributor cap. I mentioned the dash lights did not come on when I turned the key to the ON position. Also had to play with the accelerator.
Cap was wore out. Did cap rotor plugs wires. Turned key to on position…dash lights came on, twisted key and the old girl started right up. Sounds smoother than ever.
Thanks guys
A worn dizzy cap might well cause a weak spark and poor idling / poor acceleration / missing / etc. So it’s great you got that fixed and the engine is purring again.
I wouldn’t have guessed however a bad dizzy cap would have anything to do with the dash lights turning on like they should w/the key is on but the engine not running. Does your shop have any explanation for that?