HOrnbrod Posted February 24, 2018 Share Posted February 24, 2018 Stick a timing light on the #1 plug and see where it's firing at using the timing marks on the balancer and timing cover. You can't time it, but the light will tell you if it's way advanced or retarded. Link to comment Share on other sites More sharing options...
DirtyComanche Posted February 24, 2018 Share Posted February 24, 2018 A friend of mine just got a bad one off Rockauto. He didn't say what brand or P/N it was, I didn't think to ask. He then bought the exact same brand and P/N from Lordco and it was correct. He said the windows were a bit too large and the timing light confirmed the timing was going all over the place. However it would not idle. Knowing him, he probably bought the ATP because it is cheapest. Kicker is that his is a HO, or so I believe. (ATP is cheapest for either) Link to comment Share on other sites More sharing options...
carnuck Posted February 25, 2018 Share Posted February 25, 2018 The trans won’t like no fluid while running. It can fry the front pump. Did you maybe leave the ground loose?Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Dando Posted February 26, 2018 Author Share Posted February 26, 2018 Ok so some progress. I have filled the trans, it had no affect on the issue. It's still idling strong but once off idle stumbles like hell and backfires a bit etc. I set the engine to cyl 1 tdc and checked my distributor, and the trailing edge of the rotor is right where it should be. Just to check I Installed it once 180* out and it wouldn't run at all (obviously). I set my tps with a reference voltage of 4.88v and a output of .82v and still no Change. The truck moves in drive/reverse etc as long as it stays at idle, what else can I check? Link to comment Share on other sites More sharing options...
Dando Posted February 26, 2018 Author Share Posted February 26, 2018 After playing with the tps flat connector some more, I've been able to get it to idle high (2krpm), it will idle normally after connecting and reconnecting it. No matter where it idles as soon as throttle is applied it acts up. I'm starting to suspect a bad tps? A new one won't be in for me to try till morning. Link to comment Share on other sites More sharing options...
DirtyComanche Posted February 26, 2018 Share Posted February 26, 2018 You can put your meter on the TPS and move it through its travel to ensure output is linear. If it jumps all over it is bad. Link to comment Share on other sites More sharing options...
Dando Posted February 26, 2018 Author Share Posted February 26, 2018 27 minutes ago, DirtyComanche said: You can put your meter on the TPS and move it through its travel to ensure output is linear. If it jumps all over it is bad. Will this work with a digital meter? And if so what readings should I see? Link to comment Share on other sites More sharing options...
HOrnbrod Posted February 26, 2018 Share Posted February 26, 2018 You should use an analog meter to test linearity. Link to comment Share on other sites More sharing options...
gogmorgo Posted February 27, 2018 Share Posted February 27, 2018 If you're real slow on the movement you can use a digital, it just takes forever to watch it react, like open a tiny bit and wait for numbers to stabilize, etc. But analogue will be much better, as you'll watch the needle jump if it hits a bad spot, without having to wait. Even just a cheap analogue multimeter will work for that. Link to comment Share on other sites More sharing options...
Ωhm Posted February 27, 2018 Share Posted February 27, 2018 My DVOM (Fluke 77 first edition) has what's known as a bar graph below the numeric digital display. This digital bar graph has a considerably faster update rate (simulating analog) then the numeric display. Use this feature if equipped on your DVOM. Analog meter would be your best choice though. Link to comment Share on other sites More sharing options...
HOrnbrod Posted February 27, 2018 Share Posted February 27, 2018 I have an old Simpson 260 I've had since the mid-70's. I don't use it much except when I need to do variable output measurements. Still working on all functions like new. It looks like the below except much more beat up. Link to comment Share on other sites More sharing options...
DirtyComanche Posted February 27, 2018 Share Posted February 27, 2018 I only own digital meters. Link to comment Share on other sites More sharing options...
Dando Posted February 27, 2018 Author Share Posted February 27, 2018 Ok so I tested my tps, it checked out fine but I replaced it anyways as I had a warranty on the one I had. New one adjusted and whatnot, still no change. Idles fine at around 900 rpm. If I rev the engine at all it misfires, wide open throttle to get past it and the Rpms shoot up past 3k rpm and it runs fine at that engine speed after I've gotten through the bad part. The exhaust currently isn't Hooked up past the manifold, all connectors have been checked (unplugged cleaned and reconnected), throttle body clean, new cap and rotor, new plugs and wires, I'm at my wits end with this truck. I'm broke and the truck is a huge problem for me. I need to get this figured out. How can I confirm or rule out my new flexplate as being bad? And without cutting the tab on my distributor everything lines up like it should according to cruisers tips. Should I cut it off and try to change it? Link to comment Share on other sites More sharing options...
gogmorgo Posted February 27, 2018 Share Posted February 27, 2018 You didn't bump the vacuum line to the map sensor, or the wires, while you had the trans out? Or more specifically when you were putting it back in. Also make sure the CPS or any other wires aren't laying on the exhaust manifold. Link to comment Share on other sites More sharing options...
Dando Posted February 27, 2018 Author Share Posted February 27, 2018 10 minutes ago, gogmorgo said: You didn't bump the vacuum line to the map sensor, or the wires, while you had the trans out? Or more specifically when you were putting it back in. Also make sure the CPS or any other wires aren't laying on the exhaust manifold. Ive checked and double checked all the vac lines and electrical. Link to comment Share on other sites More sharing options...
Ωhm Posted February 27, 2018 Share Posted February 27, 2018 Since you now have a extra distributor cap, cut the window in it and verify rotor tip position again. Trailing edge of rotor should be at Number#1 tower. Otherwise suspect MAP sensor. Link to comment Share on other sites More sharing options...
Dando Posted February 27, 2018 Author Share Posted February 27, 2018 2 minutes ago, Ωhm said: Since you now have a extra distributor cap, cut the window in it and verify rotor tip position again. Trailing edge of rotor should be at Number#1 tower. Otherwise suspect MAP sensor. Already did that too, it was tight where it was suppossed to be. Does anyone think cutting the distributor mounting tab and spinning the distributor body would make up for a slightly incorrectly indexed flexplate? Link to comment Share on other sites More sharing options...
Ωhm Posted February 27, 2018 Share Posted February 27, 2018 If your base timing is correct at idle, your flexplate show good. Keep in mind rotating the dist will NOT change timing. It will only change Dist indexing. Link to comment Share on other sites More sharing options...
Dando Posted February 27, 2018 Author Share Posted February 27, 2018 Just now, Ωhm said: If your base timing is correct at idle, your flexplate show good. Keep in mind rotating the dist will NOT change timing. It will only change Dist indexing. Can you explain that better for me? i guess to don't see how it would change the indexing but not the timing? Link to comment Share on other sites More sharing options...
Ωhm Posted February 27, 2018 Share Posted February 27, 2018 The distributor has no "fire the coil" gadget in it to rotate. Timing uses TPS, MAP & RPM's. Link to comment Share on other sites More sharing options...
Dando Posted February 27, 2018 Author Share Posted February 27, 2018 1 minute ago, Ωhm said: The distributor has no "fire the coil" gadget in it to rotate. Timing uses TPS, MAP & RPM's. Thanks, i will try to replace the MAP with another one i have in my parts stash and see what happens. I know the vac line to it is good for sure. Link to comment Share on other sites More sharing options...
Dando Posted February 27, 2018 Author Share Posted February 27, 2018 No Change with different MAP sensor. I worked my way through thread after thread of broken image links (thanks photo bucket) to finally find a comparison image from someone that has had an issue before. The cps ring on his image is about an inch or so off from the proper indexing, he even compared different aftermarket suppliers to see and they all had that same problem. I am going to try to source down a stock flex plate, the worst part is i can't even compare a new one to my stock unit because the center is completely separated. What a bummer. I called the manufacturer ATP, and when speaking with them they claim to have not a single complaint about this part, claiming i am the first to ever have an issue like this. Bigger bummer. Oh well, i guess i will change the cps just to see if it makes a difference (even though it starts and runs currently) before i rip the trans out again. Anyone have a stock flex plate? (already made a classified post) Link to comment Share on other sites More sharing options...
Ωhm Posted February 27, 2018 Share Posted February 27, 2018 On 2/24/2018 at 12:50 PM, HOrnbrod said: Stick a timing light on the #1 plug and see where it's firing at using the timing marks on the balancer and timing cover. You can't time it, but the light will tell you if it's way advanced or retarded. On 2/26/2018 at 12:47 PM, Dando said: I set the engine to cyl 1 tdc and checked my distributor, and the trailing edge of the rotor is right where it should be. Just to check I Installed it once 180* out and it wouldn't run at all (obviously). 2 hours ago, Ωhm said: If your base timing is correct at idle Did you put a timing light on it? Link to comment Share on other sites More sharing options...
Dando Posted February 27, 2018 Author Share Posted February 27, 2018 6 minutes ago, Ωhm said: Did you put a timing light on it? I did not as I don't own one. What would this tell me though that checking my distributor doesn't? Link to comment Share on other sites More sharing options...
HOrnbrod Posted February 27, 2018 Share Posted February 27, 2018 It will tell you the advance or not from TDC, and also if it's flaky (jumping around) or not. Suggest you invest in a decent timing light. Link to comment Share on other sites More sharing options...
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