Shimmey Revisited
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I would check the plenum gasket then. (just look down the throttle bores, with throttle wide open, engine NOT running.... 
) See if there is oil down there. If there is, that makes for a pretty significant vacuum leak, which leads to munched up cat converters. It's a job you can do at home, with basic hand tools, or, you can pay someone else to deal with, if you prefer.
) See if there is oil down there. If there is, that makes for a pretty significant vacuum leak, which leads to munched up cat converters. It's a job you can do at home, with basic hand tools, or, you can pay someone else to deal with, if you prefer.I have a diagnosis scheduled Monday. This van sat for a long time and the check valve in
the gas line is stuck- I turn the key 3 times quickly to run and 4th time starts right up. They said they will check the fuel pump and also fuel injectors among other things. I'll post what they come up with.
Thank you
the ignition system I replaced (coil also) was so bad- corrosion, white powder, plugs gapped at 80 instead of 35- I keep thinking that may have caused my current problem. Amazing how well the van did run.
Last edited by arty4444; Jun 21, 2019 at 03:55 PM. Reason: More
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After thorough shop diagnosis turns out my fuel pump regulator is way out with the PCM fighting it to not put too much pressure to the injectors. Fortunately all the other work I did except the cat. converter was very much needed anyway.
Thanks for your help HeyYou.
actually I should wait until Wed. when the new pump unit is installed for my victory dance.
Thanks for your help HeyYou.
actually I should wait until Wed. when the new pump unit is installed for my victory dance.
Last edited by arty4444; Jun 24, 2019 at 01:54 PM. Reason: More
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Getting there. New fuel pump unit replaced orig. which was diagnosed;
""81 psi idle w/drop under hard accel. below 45 psi with pressure to zero as soon as key off. Fuel trim negative 17%"" whatever that means.
I knew the check valve wasn't working and was keying up 4 times to start. That is fixed and power uphill is good now also. The loss of power was my main concern.
The shimmey is still there like before and has been progressing for at least 4 months. But still on acceleration only. At first uphill only then on flats and now accel downhill too. Shimmey increasing in magnitude but always stops right away when accel. over.
With what seemed a thorough and very professional engine diagnosis showing fuel pump problems only I'm looking at the drive train- even parts recently checked and or replaced. I think I'm correct to rule out balance and alignment because there is never a shimmey at any speed coasting. Within last year had new Moog top ball joints intstallef up front, drive shaft balanced with new u-joints, put 2 idler arms in myself and lubed all fittings. Those orig. idler arms had a ton of play with a clunk on turns cured now but I remember the new ones looked cheaply made. Had a guy at Tire Kingdom tell me my control arms needed work but he was the one that put in the top ball joints to fix my clunk without a word on the extremely loose idler arms which did the job the ball joints didn't fit so I know he would milk me and didn't believe him. And there was no shimmey or any other problem for a good year after just the ball join and arms.
Sure is nice not to have to "4-key" for start up.
Oh and just in case I'm going to dissconect neg. bat. terminal for half hour in case PCM still thinks my fuel regulator is still bad.
Thanks
""81 psi idle w/drop under hard accel. below 45 psi with pressure to zero as soon as key off. Fuel trim negative 17%"" whatever that means.
I knew the check valve wasn't working and was keying up 4 times to start. That is fixed and power uphill is good now also. The loss of power was my main concern.
The shimmey is still there like before and has been progressing for at least 4 months. But still on acceleration only. At first uphill only then on flats and now accel downhill too. Shimmey increasing in magnitude but always stops right away when accel. over.
With what seemed a thorough and very professional engine diagnosis showing fuel pump problems only I'm looking at the drive train- even parts recently checked and or replaced. I think I'm correct to rule out balance and alignment because there is never a shimmey at any speed coasting. Within last year had new Moog top ball joints intstallef up front, drive shaft balanced with new u-joints, put 2 idler arms in myself and lubed all fittings. Those orig. idler arms had a ton of play with a clunk on turns cured now but I remember the new ones looked cheaply made. Had a guy at Tire Kingdom tell me my control arms needed work but he was the one that put in the top ball joints to fix my clunk without a word on the extremely loose idler arms which did the job the ball joints didn't fit so I know he would milk me and didn't believe him. And there was no shimmey or any other problem for a good year after just the ball join and arms.
Sure is nice not to have to "4-key" for start up.
Oh and just in case I'm going to dissconect neg. bat. terminal for half hour in case PCM still thinks my fuel regulator is still bad.
Thanks
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Maybe the guy was right about the control arm bushings. My symptom exactly- vib. on accel. disappears with foot off gas. That's next- closing in.
Last edited by arty4444; Jun 27, 2019 at 10:23 AM. Reason: Spelling