the idle adjustment screw seems inaccessible. it has a little cap on the end. I don't think it has been touched.

 

thought I would also mention that I don't think my ignition coil is grounded... it is just loose since I had to move it so many times to get at the distributor bolt I just left it loose until I figured out my problems. does it need to be bolted down?

 

Just to be sure, I bolted the ignition coil down for grounding. I also verified w/ a noid light that each fuel injector is being pulsed. I verified that each spark plug is receiving spark with an in-line spark tester. I will try to get the ALDL cable up and running as it just arrived :-) Still, at best, idles around 450 rpm...

 

WINADL outputs whilst running (crappily). MPH, EGR, and RPM all read zero. is that normal? Anything else noteworthy?

 

Your driving ? Code 24 or 42 ?

 

oh, no. just idling in the garage - terribly around 450 RPM. same state as before. so MPH should be zero. But, I figured EGR and RPM should be something other than zero.

 

I'm not a WinALDL user, so I don't have a feel for the output, but at least RPMs should register once the engine is running, no matter how crappy.
MPH is of course zero in your case and I think EGR duty cycles only start when operating temperature has been reached.

BLMs and INTs are 128, so totally in the center or at default values. These values show how the ECM is choosing how much fuel to add to the mixture.
In a perfect world, these values would be perfect, but in this case it means something's missing for calculation.

The rich/lean counter should kick in after engine temps get higher and shows how the O2 sensor swings about, so the ECM can adjust the air/fuel mixture to get the proper exhaust gas for emissions.

Any error codes?

And... (have I already asked?) have you ever checked your catalytic converter for blockage? Does it sound like loose stuff inside when you give it a good smack?

 

Thank you! Um, I will run this again to verify RPMs are zero again. I haven't checked for blockage. I replaced the cat-back exhaust and when I was looking in at the cat I didn't see anything odd. But, I can't see the down pipe side. I'll give it a good whack :-)

How is RPM measured? Still wondering if I messed up the distributor rebuild somehow.

 

Sorry, forgot to answer your question: no codes!

 

Got some RPM values the second time. 250-300RPM

 

RPMs definitely have to do with the distributor.
Curious that there are no codes, so you must have a combination of factors that don't warrant setting any codes.
If I remember this right, you need at least 400 RPM for the electronic spark timing (EST) adjustments to even begin, so if you don't reach 400, the engine will be running on minimum idle as set by your distributor position and minimum idle screw (that you haven't touched).

Here's the procedure:


And here's something regarding closed loop requirements:

 

Thank you. As you mentioned, I haven't messed w/ the idle screw so that shouldn't be the problem, right? I am going to try a whole new distributor this weekend. I didn't like how the old one went back together after I put in the new pickup coil. For some reason there was a lot of friction and it didn't spin easily. I thought maybe I messed something up.

 

Was not the distributor! Good thing I didn’t buy the $500 MSD one 😊 I just got a new Carquest Premium ($180). Do you still think I should mess w/ the idle screw? Could I just shim it with cardboard temporarily? Btw, sometimes when I start it, it’ll rev up (by itself) to 3000 – 3500 RPM and then drop dead. When it does rev up, it doesn’t backfire or anything. It sounds rather smooth.

 

Why not look at iac steps on winaldl engine warmed up ?

 

I haven't seen any of his winaldl screenshots where the coolant temperature is hot enough to put the vehicle in closed loop and one can only assume that IAC @ 145 is the engine start parked position which I've never seen it plummet from that number.

 

Yes 75f and 81.5f in the screenshots, normal to be 145-160 steps. Hard to tell anything from the screenshots cold engine.

 

I captured the following WINALD outputs. Anything stand out to you?

 

7.5 ms at idle , I bet that’s pig rich . I don’t see the cause. Any change by smacking the ecm ?

 

No change by smacking the ecm :-) Could replace it if we've run out of options?

 

I hate to say throw parts at it, maf gps and coolant temp seems like they are working. Engine warm it should be 2 ms. TPS looks good too. I wonder if you could find anyone close with a 86-89 tpi and use your chip to try a different ecm.

 

Current progress video below. When idle is smooth, timing looks about 12+ advance. This is an improvement from where I had it. It was significantly retarded and would start and idle around that 400 rpm. I put the light on it and advanced it and get up to where you see in the video. Timing is hard to read at idle and jumps a lot. Very steady if I can get the idle to smooth out. There is an exhaust leak. The new exhaust (cat-back) isn’t fitting to the cat well. But, that wasn’t an issue previously other than the sound of a leak.

Thoughts?

 

I haven't read every single post in the thread, but I don't think I saw this mentioned. it may not be a whole cause, but double check your spark plug wires / firing order. it's really easy to get wires 5 and 7 mixed up on this car that will cause it to run really rough.

 

thank you! Yes, I have double-triple checked :-) My wires happen to be numbered at both ends too. i should start including a summary :-)

 

log file attached from WINALDL capturing the raw data and sensor outputs. Anything look suspicious? I have difficulty keeping it idling. I have to keep the throttle open a bit and it surges.

 

I pop in from time to time tbh I'm gonna be all over the map...73 replies and not one mention of what the actual fuel pressure is. Fuel pressure is good last time I checked is about as useful as my tires look round so the tire pressure must be good. Fingernail on the shrader valve sending fuel onto the bottom side of the hood means nothing. Tell us or better yet post a picture of the actual fuel pressure gauge showing us the appropriate fuel pressure.

Ironically every time I click on this thread it starts at post #51...post #61 clearly shows a picture of the cap/seal being removed to expose the adjustment screw to adjust minimum idle.

The mere fact that you can keep it running with small throttle movements could possibly mean that it could benefit from more air. On a whim I would create a vacuum leak by pulling a vacuum hose to see if it improves the idle. Keep in mind if you use the FPR vacuum hose, this will increase fuel pressure which in turn will increase fuel delivery but maybe that's what it wants.

Speaking of fuel pressure...which injectors did you replace them with? Hopefully #/hr equivalent to stock but there's no mention of it.

One of my post I mentioned the engine needing to be warmer before there's going to be any useful data. I understand that it's difficult to keep the engine idling but ~80dF to 115dF, well that's a slight improvement but looks like the engine is still in open loop. You need to force the cold engine to run for at least 3 minutes before it'll go into closed loop and see if it improves the way it runs.

Regardless...it should idle perfectly in open loop...

I probably have a few more thoughts but I'm being summoned to step out for a meal...

 

Thank you! I captured a video of starting and running it. Link below. Also, I attached the WINALD output captured while it was running for about 7 minutes. Got up to 160 degrees F. I caught the fuel pressure on video holding around 38 - 40 PSI.

Summary: checked plug wires multiple times. they are numbered on both ends. new wires, new plugs. New distributor, cap, rotor, pickup, ignition control module, coil, IAC, TPS, MAF. New fuel pump, fuel filter, fuel pressure regulator, and injectors. Verified all plugs receive spark. Verified all injectors receive electrical commands with a noid light. Timing somewhere around 12 degrees advanced.

 

Thanx for confirming the fuel pressure!!! The biggest thing that sticks out is the low O2 volts indicating a lean condition. I wonder if that "struggling to idle" video you posted^^^where you mention "pop pop pop" is a an exhaust leak upstream of the O2 sensor. That could possibly make the O2 sensor report erroneous feedback to the ECM.

 

It hasn't popped as much since yesterday when I replaced the intake gaskets and tightened the bolts. The pop sounded like it was coming from the plenum previously. i did some googling and loose bolts possibly cause that. The right lower intake runner gasket was misshaped for some reason. So, I replaced that and tightened it all up. I didn't hear any real pops this time. Also, there IS an exhaust leak. I put a new cat-back and the flange to the cat is not fitting quite right. But, other than some noise, it wasn't a big issue when it was previously running. I figured I'd have a shop deal with the exhaust for me. Do you think it is a bigger issue? I could try temporarily tightening up the flange to eliminate or minimize the leak?

Summary: checked plug wires multiple times. they are numbered on both ends. new wires, new plugs. New distributor, cap, rotor, pickup, ignition control module, coil, IAC, TPS, MAF, EGR valve. New fuel pump, fuel filter, fuel pressure regulator, and injectors. Verified all plugs receive spark. Verified all injectors receive electrical commands with a noid light. Timing somewhere around 12 degrees advanced.

 

Was checking vacuum. I can only advance so much before the cables start to strain. But, with an advance of whatever the top of the marker is on the balancer, running at 750-ish RPM, vacuum is low, around 10 inches. It is also a bit choppy down there. At 2700 RPM it is smoother, but the vacuum there is only about 15 inches. While at 750-ish RPM I tried advancing more (not sure how far since I'm already above the marker) and vacuum improved a little but it wasn’t going to get anywhere near 17-20 inches from 10. This mean anything?

Thank you for your thoughts,
Tom

 

here is a status video:
Summary: checked plug wires multiple times. they are numbered on both ends. new wires, new plugs. New distributor, cap, rotor, pickup, ignition control module, coil, IAC, TPS, MAF, EGR valve. New fuel pump, fuel filter, fuel pressure regulator, and injectors. Verified all plugs receive spark. Verified all injectors receive electrical commands with a noid light. Timing somewhere around 12 degrees advanced.

 

Earlier in this thread you mentioned how you lined everything up and made sure the rotor was pointing to #1, Even before you decide to check the timing, I would make sure your TDC is actually at TDC and it matches the mark on the harmonic balancer. Verify before you trust whatever it is that you're trying to do in the video with the timing light. If you don't know how to set the timing on these vehicles, then visit this link: https://www.thirdgen.org/settingtiming/ and furthermore, yeah you might set it at 6* but once the computer takes over, spark advance is going to be whatever is programmed into the PROM that the engine is going to running at.

Oh and one more thing you said...if your spark plug wires were infinitely long, you could twist the distributor as much as you want well at least if the engine continues to run. This tells me you could possibly be a tooth off that's not allowing you to add any more timing or perhaps the ring on the balancer could have slipped.

 

Okay, thank you. Let me double check the timing w/out the EST. I think I did that most recently and w/out EST it was about 0 deg. Regarding the balancer or tooth, is that likely to have happened recently? The car was running okay before I started mucking around to diagnose fuel issues and hasn't driven since this idle/stalling issue.

Best,
Tom

 

I forgot this is a low mileage car so I would dismiss the balancer slipping. As for the distributor, the wires are the only thing limiting you from turning it more to advance. If it is a tooth off that's because you stabbed it that way.

 

Thank you. When i checked timing yesterday w/out EST connected, it was about 2 degrees. wasn't exactly 0 degrees. With EST it was probably just above the highest marker. So, what's that, 12? Is that good enough? I was trying to advance it a LOT to see what happens at the extreme and that is why i mentioned I could only go so far w/ the wires.

 

Iirc, it calls for 6* advanced. Personal experience tells me they are happier set to around 10-12* advanced. That's with the tan/black wire disconnected.

 

Making some progress!! Idling pretty smoothly now. You could hear in some of the prior videos that the engine would surge. I started unplugging things and when I unplugged the TPS the surging stopped. I reconnected TPS and surging is still gone. Possibly the connection wasn't that good? I can't be sure.

At the moment, I have the base timing w/out EST set at 8 degrees advanced. With the EST connected, at idle, it is probably 20 degrees (hard to guess). Idle is high ~ 1250 RPM but smooth. What should the idle be? This is a 5-speed. I intend to collect a set of WINALDL data from a cold start to warm-up.

Summary: checked plug wires multiple times. they are numbered on both ends. new wires, new plugs. New distributor, cap, rotor, pickup, ignition control module, coil, IAC, TPS, MAF, EGR valve. New fuel pump, fuel filter, fuel pressure regulator, and injectors. Verified all plugs receive spark. Verified all injectors receive electrical commands with a noid light. Currently running!

 

1250 RPM is too high, should idle ~700, but I'd go drive it some and see if it settles down to a better/lower idle after driving it above ~35 mph. And...just driving it some could help, IMO.

 

I reset the base timing again and unplugged the battery for a while to clear any codes. This time, as it warmed up, it eventually got down to about 750 RPM and was stable and responsive. Will take it for a drive soonest and report back.

Summary: checked plug wires multiple times. they are numbered on both ends. new wires, new plugs. New distributor, cap, rotor, pickup, ignition control module, coil, IAC, TPS, MAF, EGR valve. New fuel pump, fuel filter, fuel pressure regulator, and injectors. Verified all plugs receive spark. Verified all injectors receive electrical commands with a noid light. Currently running!

 

Glad to hear about some progress! The TPS or its connection can cause issues, yes, but you should see it going all over the place in WINALDL if that's the case.
Looked quite constant in all those screens you shared, so I did not suspect it.
Also, a TPS issue only goes so far, because if voltage is to high, the ECM expects more air and enriches the mixture. In the end the engine suffocates.
Low voltage means the mixture has to be leaned out. Same result.
The range in which the engine can still operate on a bad mixture must be pretty small and I don't think those massive surges are within that range.
Though I do hope they are and you can finally move on!

 

I don't think the TPS meaningfully affects the AF ratio, other than when it's actually moving. Agree, though that it seems odd that the TPS would have solved to problem.

 

Actually, TPS didn't do anything :-) I think it is probably fine. My timing went off again. Reset timing to 8 degrees advanced w/out EST connected. Seemed pretty stable and I tightened down the distributor. latest log is attached from WINALDL. Simple cold start to warm up. Started fine. Minor stumble but it didn’t stall and quickly returned to high idle. Then came down to about 1100. Slowly crept up to about 1250. Timing remained probably 20 advanced. Anything look odd?

Best,
Tom

 

I drove it around as someone had suggested earlier. Didn't seem to help the idle. Other than the high idle, it seemed to run really well and was responsive. I had set the base timing without EST to about 8 degrees which was probably about 22 degrees with EST. I then tried bringing the timing down to about 6 degrees WITH EST connected to drop the idle. I got the idle to around 750 rpm but it definitely didnt have the same responsiveness. was boggier at low RPM. I am confused as to why my idle is so high when the base timing WITHOUT EST is 8 degrees.

Best,
Tom

 

Couple more clues from WINALDL. I ran idling for about 15 minutes from cold start-up. the biggest thing that stuck out was the rich flag was consistently set and the engine never reached closed-loop. it warmed up to about 200 degrees. O2 sensor outputs were not static but did vary anywhere between 0.5v and 0.7v. BLM was consistently around 80 toward the end. seemed like the ECM was trying to take away fuel?

Summary: checked plug wires multiple times. they are numbered on both ends. new wires, new plugs. New distributor, cap, rotor, pickup, ignition control module, coil, IAC, TPS, MAF, EGR valve, PCV. New fuel pump, fuel filter, fuel pressure regulator, and injectors. Verified all plugs receive spark. Verified all injectors receive electrical commands with a noid light. Timing at 8 degrees advanced w/out EST - probably around 20 w/ EST. Idling high around 1250 RPM but other than that, seems responsive and drives.

Best,
Tom

 

with the vacuum leak it seems rich

 

are you saying you are suggesting there is a leak? I haven't found one yet but there definitely could be. I also wanted to include this screenshot because I thought the MAF values of 9.55 g/s seemed high for 1200 RPM. do you think so?

 

Command in the iac and unplug it. See what idle is then. If still high yes you have a leak. GPS seems inline with rpm

 

thank you. I found a leak! i used the method of spraying the carburetor cleaner at different seals. driver's side lower rear runner bolts were not that tight and had a pretty sizable gap. after that the idle seemed to wobble around a lot but would at least come lower to 750 rpm. also the exhaust started to smell like eggs. i will collect some WINALDL data again.

 

Killing the cat 🐱

 

ah. okay i let it sit for a bit and cleared any error codes. Tried again. no fowl smell but it didn't reach closed loop. It did set the EECC Slow 02 Rich/Lean Flag and Rich Flag on WINALDL. Idle RPM came down a little bit. got as low as 975 RPM but not lower. Was pretty steady. I checked for more vacuum leaks but couldn't find any. What do those flags mean?

Best,
Tom

 

Not sure on the abbreviations , I prefer tuner pro rt and $6e. It takes a swinging o2 and cts to be 165f or higher to get cl to occur.