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Hesitation and flooding...

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  • Hesitation and flooding...

    I have another thread going on over at .net, but figured I'd try here too...

    I've been having this hesitation issue for a while. But it's a hesitation from what I think is flooding. When the truck is parked and idling, if i barely tap the gas the AFR goes to 10.0, the rpms dip, and then the engine revs up. It does this whether it's hot or cold, in park, reverse, or drive. From a stop light, I'll hit the gas, and it's the same thing, rpms dip, then it picks up and goes. It does this when I slow down and accelerate out of a turn. If I get on the gas it'll get up to about 5-7psi before the rpms start bouncing around and the truck bogs out. Idle smells rich, and MPG is not good either. I also get random pops/misses at idle. Fuel psi is good and solid, and climbs # for # with boost.

    I have 50# injectors, a turbo tweak chip, AFPR, PLX WB02.

    I did the bike inner tube trick on the upper IC, and there's no vacuum leaks other than a slight hiss coming from the bottom of the throttle body...

    So far I've replaced the cap/rotor, plugs, coil, ICM, and MAP sensor. I don't have anything to test the plug wires, but I took a spare good plug wire and swapped it out on every cylinder with no change. I don't think it's a bad or clogged injector, because it's going rich instead of lean.

    I also get this buzzy/ticking/grinding sound every time I tap the gas...I can hear it in the cab and under the hood... I made a video of it with a link below... In the cab it kinda sounds like pushing a plastic bucket upside down on concrete... under the hood it sounds like taking a comb and dragging it down the edge of a table real quick... and it sounds like it's coming from the distributor.

    https://youtu.be/FBt9aRIH_6A


    Just curious if anyone here has any ideas... or heard these noises before.

    Thanks in advance and have a good weekend!

  • #2
    Does it make the bucket sound or the comb sound when the engine's not running and you hit the throttle? Possibly linkage noises?

    Hesitation and stumbles are typically ignition related. The tach bouncing is ignition related. Are there any loose grounds anywhere?

    What kinda of fuel pump is on your truck? How long has it been in there?
    -Brandon

    Why is EVERYBODY racing on low boost?

    Comment


    • #3
      Originally posted by Aeroking View Post
      Does it make the bucket sound or the comb sound when the engine's not running and you hit the throttle? Possibly linkage noises?

      Hesitation and stumbles are typically ignition related. The tach bouncing is ignition related. Are there any loose grounds anywhere?

      What kinda of fuel pump is on your truck? How long has it been in there?
      It only does it when it's running, and it doesn't matter if it's hot or cold. If I advance the throttle while under the hood with the engine off it doesn't make any noise, so it's not the linkage.

      I have a Walbro 255 in there with about 3k on it, and fuel psi is always solid. I checked the grounds too, and there's nothing loose or suspect there... I'm with you thinking it's ignition related, although usually when there's an issue with the distributor it makes a noise all the time, not just when you rev the engine...

      I ordered a new distributor anyway, since that's where the noise is coming from. The water pump is squeakin and leakin too, so I gotta do that next. The perils of daily driving a 28 year old truck haha.



      Comment


      • #4
        Sounds like spark arcing to me. You could have spark leaking to ground possibly a damaged plug wire, cracked cap/plug, coil etc.

        Comment


        • #5
          Well, I put a new set of wires in, and!!! Nope. Still having the same problem. I caved and bought a multimeter just cause it's probably a good thing to have around the house and to test my old wires. As it turns out #6 and #4 were indeed arcing, which is why I couldn't find the problem when I was swapping out 1 wire at a time. The idle has smoothed out a bit and hesitation isn't as bad as it was, but the AFR still goes to 10 when I tap the gas, and it still bogs out at 5psi with AFR going to 10. I also still have the noise when I tap the gas.

          I'm gonna have to get the stethoscope out and see if I can pinpoint exactly where the noise is coming from. Initially I thought it was coming from the distributor, but now I don't think it is. Is it possible for an injector to arc? I'll post what I find or don't find with the stethoscope.

          Comment


          • #6
            If its arcing you should be able to see it at night. Park in a real dark area and pop the hood and see if you can see anything jumping around the coil area. I dont think its possible for an injector to arc.

            Comment


            • #7
              Originally posted by Static View Post
              If its arcing you should be able to see it at night. Park in a real dark area and pop the hood and see if you can see anything jumping around the coil area. I dont think its possible for an injector to arc.
              Correct, Injectors are 12V pulsed GND, arcing is impossible.

              Comment


              • #8
                Originally posted by Typhoon0627 View Post
                the AFR still goes to 10 when I tap the gas, and it still bogs out at 5psi with AFR going to 10.
                What calibration ("PROM") is in it? I'm guessing it is not a stock calibration, because I don't see how a proper calibration could do this. An aftermarket calibration with a mistake or overlooked calculation could.

                I will never, never, NEVER forget trying to help a guy on .net chase a code 21 TPS high. We went around and around for two weeks, and nothing made sense. He had data logs, and he was NOT meeting the parameters to set Code 21. It was impossible. After two weeks, the author of the PROM came in and said he changes the parameters for Code 21, and that it was likely that he WAS setting 21. What the F? Why change the parameters of a DTC and not tell anyone? Makes diagnostics impossible for anyone. The author of this PROM has the word "weak" in its name.

                I tell this story to illustrate that one has to be cognizant of "mistakes" or "issues" with other than stock calibrations. There can be anomalies that haven't been uncovered by exhaustive validation like only the OEM can perform.

                EDIT: I see you have a xxxxxxweak chip. I've seen peeps with these chips have so many weird problems that I don't even try to figure issues with trucks with these chips out.

                Having said that, the loss of power, break-up, and "bog" at 7 psi is EXACTLY what my red/gry did when it had a plugged cat. Took me 3 weeks to figure it out.
                Last edited by DaveP; 04-13-2019, 12:27 PM.

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                • #9
                  The noise is too perfect to be arcing. Sounds more like maybe a noisy IAC, I don't think it's related to the rich \ hesitation issue.

                  What is the full mod list?

                  Was this truck running fine at some point and then this all started?

                  Have you tried putting the stock chip and (2) bar map back in it?

                  Is the TT chip installed correctly?

                  Have you datalogged all this?

                  Have you sent Datalogs to Eric?

                  Can you post the datalogs?

                  I'm with Dave - this sounds like a TT gremlin, and we're all blind to knowing what's really going on.


                  There are 7 adjustable settings built into the TurboTweak Velosyty chip for the GMC Syclone and Typhoon. This article will cover all the software and hardware settings in the chip. This article is based on content of the Velosyty Version 2.0 chip documentation. Their docs are available on their site in pdf format. You'll need a scan tool that can display INT and BLM (or LTerm) to make adjustments outlined in this article.

                  Comment


                  • #10
                    Thanks for the responses guys...I'll try to tackle all of the questions in one reply, but first... I got the stethoscope out and the noise is coming from the injectors. I didn't have time to pull the upper IC off to test all 6, but the 3 on the drivers side measure 12.6 ohms, so they're not "bad". They tick like normal at idle, but as soon as I advance the throttle they make the noise which sounds like a relay chattering when I listen to each one through the stethoscope.

                    So here's where I'm at... I failed smog a couple weeks ago as a result of excess HC counts which the tech said is usually the result of running too rich.

                    My 2009 XP laptop has shat the bed and decided it no longer wants to turn on, so I'm SOL on data logging... my ALDL cable is OG from 2001 so it has a serial connector on the end of it which is all but non-existent on computers these days. Unfortunately you can't just go buy a serial to USB convertor and have that work with a Windows10 laptop, and Datamaster doesn't work with Windows10 anyway... So that leaves me with TunerPro which I've never used, and I had to order a new ALDL to USB cable, so I'm waiting on that.

                    Last weekend I pulled the TT chip, and popped my Ostrich in there, and loaded in a bin for 50# injectors... In fact I tried several different bins and they all idle super rich. I messed with the fuel tables on one of the bins in TunerPro, and got the idle to lean out to 14.x, but it was pretty rough, and the truck barely made it down the street and back when I tried to drive it, so that's not gonna work.

                    One thing of note... when I got the idle to lean out, I got the stethoscope out and put it on the injectors and they didn't make the noise when I advanced the throttle... I blindly adjusted out more fuel across the whole table and when I tapped the gas it dipped to 12.5ish and then went lean... which kinda makes me think it's something with the TT chip that's causing the noise in the injectors and for the AFR to dip down to 10.

                    Dave, in regards to your comment about it being a plugged cat... With the TT chip my truck runs fine on the freeway and AFR hovers in the 14's when cruising at 70-75mph. It doesn't feel sluggish if I get on the gas to change lanes, and it pulls pretty good up to about 5psi, and then I can watch the AFR gauge drop to 10.5 and feel the truck bog out. Did your truck with the clogged cat run ok outside of boost? Meaning could you even tell there was a problem unless you got on it?

                    What is the full mod list?
                    AFPR, fuel psi set to 42psi, Walbro, Delphi 50# injectors, KB CAI, ITS mini external wastegate on crossover, PLX WBo2, AEM TruBoost Boost controller, TTchip, 3bar MAP sensor, fresh CR42TS plugs gapped to .032, new MSD cap/rotor, new wires, new ICM, new coil, Sportmachines silicone vacuum lines (no leaks), even new windshield wipers!

                    Was this truck running fine at some point and then this all started?
                    No, it's had this hesitation ever since the TT chip and new injectors were installed... I just kept putting it off cause the Ty wasn't my daily, now it is.

                    Have you tried putting the stock chip and (2) bar map back in it?
                    I don't have a stock chip, I have an ATR pitbull chip, and I can't go back to that and the 2 bar because it won't run with the 50# injectors.

                    Is the TT chip installed correctly?
                    Yes. I've taken this thing in and out probably 20 times in the past month

                    Have you datalogged all this?
                    Yes I have some DM files from a couple months ago

                    Have you sent Datalogs to Eric?
                    Yeah

                    Can you post the datalogs?
                    I'll try again, I tried hosting them on my cloud, but apparently the link doesn't allow you to download the file.

                    I'm with Dave - this sounds like a TT gremlin, and we're all blind to knowing what's really going on.
                    I think you guys are right. The next question would be if anyone has a 50# bin file they know works, that they could email me?

                    I'm in a bit of a predicament now because my Ty is currently my daily, so I can't take out the TT chip and send it back to Eric without something else to put in there so I can drive the truck. I'm also on somewhat of a time crunch because even though I paid my registration I don't have the sticker because I failed smog... and even better, Friday I'm leaving for Seattle for 2 weeks, so I won't even get a chance to mess with any of this til I get back. If i could get a 50# bin that works with the ostrich, I could send Eric the chip while I'm gone... I'll try messing with this more when I get home from work... and keep you guys posted.

                    thanks for the help and insight!
                    Last edited by Typhoon0627; 04-23-2019, 08:31 PM.

                    Comment


                    • #11
                      I have my last 50# bin but it’d be for Vortecs and a cam.

                      Just load one of the Tooky bins. (http://powertuneplus.com/syclone/58bins.shtm)

                      Comment


                      • #12
                        Go to power tune plus and download one of the code 58 bins that are on there for stock motor 50# injectors 3 bar.

                        I tried to to post the link but apparently posts with links have to be approved or some nonsense.

                        Comment


                        • #13
                          Back from Seattle, and have my new aldl to usb cable in hand. I'll try screwing with some of the bins from Tooky's site tonight. Eric sent me another eprom which I installed and the hesitation has cleared up when driving, however when I'm in park and rev the engine the injectors still make the noise and the AFR is still dipping to 10... exhaust still smells super rich too.

                          Dave, did you use a backpressure tester to see if the cat was bad? I need to call around to see if anyone has one I can rent. Also, what cat did you replace it with? Looks like the Magnaflow 339486 is the preferred CA option? I love that they cost more than twice as much as the non-CARB cats, but that's a rant for another time.

                          One thing I read online is that you can pull the o2 sensor out and drive it around to see if it feels more responsive, as a quick n dirty test to see if the cat is clogged... I did that, and it could be just the placebo effect, but it does feel more responsive and the idle seems to be a lil better too. It drove like shit around the block though, presumably because there's no o2 sensor connected? If the cat is indeed bad, this makes me think that the AFR going rich is pumping unburned fuel into the cat which clogged it up, although I never got that rotten egg smell like the innards of the cat were burning up... it just constantly smells rich. I'll try loading a bin into the ostrich tonight and see if I can make any progress there, now that I can monitor it through my good laptop.

                          ...to be continued.

                          Comment


                          • #14
                            The rotten egg smell is from an engine running rich with a GOOD cat. Hc and Co is converted into SO2, which is what you smell.

                            It took a long time to figure out the plugged cat. I was pulling my hair out, and was really out of ideas when a member Dr. Barry Tisdale sent me a PM and mentioned the cat. That was it. Dr. Tisdale passed away at least 15+ years ago, but he saved my trip to Nats 2000, we left that afternoon for KC.

                            I've found the #1 most reliable way to detect a plugged cat is to look into it on the inlet end. Requires removal, which is usually difficult. On one client's truck I had on the lift with the engine out I got the plumber guy up the street to bring his sewer-cam down and run it down the downpipe. Cat was 100% open. The cam worked really well. Cost a couple of beers.

                            Other indications are: Vacuum drops like a ROCK when the throttle is opened. Another clue was that there was ZERO knock count or spark retard at WOT prior to it breaking-up. (The backpressure causes exhaust gas to back-fill the cyl, diluting the incoming charge, so there is little pure mixture to detonate). Once the cat was replaced it detonated and knock retarded like a Typhoon should! I used another stock cat from a parts truck. This was all back in 2000 when I finished my red/gry 92.

                            Running rich will cause a cat to run at elevated, or too-high temperatures. The core is ceramic, get the temps high enough the ceramic melts and clogs passages. Eventually it may melt enough to begin to break up and chunks migrate into the muffler and plug it instead.

                            Comment


                            • #15
                              Well after a month of screwing with this truck here's where I'm at.. I took it to a local muffler shop and had them do a backpressure test and the guy said there was no backpressure, like it barely moved the needle on the gauge. He also said that I didn't have a CA legal cat on there and if the smog guy was gonna be a dick and get the mirror out, he could fail me just on that, but I've never had a smog guy get the mirror out at any smog check.

                              There's gotta be a problem with either the ECM or the IAC again... There's no code 35 or anything, but this thing still surges up to 1500-1700 rpms with my foot off the gas decelerating up to a stop, and now, regardless if it's hot or cold, when I start the truck, the idle jumps up to 1500 or so, and then it takes the computer a lil bit of time to correct it and bring it back down to normal. When I'm driving on the street, I can get up to 45-50mph, take my foot off the gas, and the truck will just continue to cruise at a steady 45mph all by itself. But it doesn't happen ALL the time, so I haven't been able to capture this on Datamaster. I've already replaced the IAC twice, and I've done the process to reset the IAC several times and no change, and I can hear it resetting, so I know it works. After I reset it, i'll start it up, and it'll idle as normal. Then I go drive to the store, turn it off, come back out and start it up, and rpms are back up at 1500 again. Part of me still thinks these injectors are crap, but that's another $300 gamble on new injectors and more time wasted if I'm wrong.

                              And because this problem isn't enough already, my AC compressor went out, along with either my steering box or the power steering pump cause the steering is super stiff now and doesn't return to center after a turn, and the water pump is leaking.

                              Who's got a gas can and matches???

                              Dave... how much ya want to test your patience on this thing? hahaha
                              Last edited by Typhoon0627; 06-17-2019, 07:54 PM.

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