Engine stumble
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Joined: Dec 2016
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Yea, slightly worse but not much difference. Did you have a similar problem? This is a low mileage truck...108000 original miles. I bought it new and have never parted with it. Its been a good truck with a few problems over the years, but that is to be expected.
Tuned
Joined: Dec 2008
Posts: 318
Likes: 20
From: Upstate South Carolina
I had that exact problem on my '91 5.8 (140k). Unfortunately I changed a few things at the same time so I solved the problem without pinpointing the exact problem (never the best thing). I suspected the PiP sensor and as it was as inexpensive to change the distributor as the parts I did that. Of course I got a new PiP sensor and ICM with the distributor. I also re-set the timing. I would start by re-checking the obvious - fuel pressure, vacuum lines, plug wires etc. Codes of course. I think some diagnostic testers can check the PiP sensor if you have access to a shop that has the right one.
Cargo Master
Joined: Oct 2016
Posts: 2,738
Likes: 217
From: Northern VA
Could be starving for fuel. Clogged sock, clogged filter, marginal pumps, bad regulator, clogged injectors....Or could be leaning out to various vacuum leaks
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I changed the fuel filter approximately 20,000 miles ago. Probably should do it again although this should be done every 50,000 I believe.
It does have the original pumps and the fuel pressure was about 32 psi and like 38 psi running. (both tanks tested)
It does have the original pumps and the fuel pressure was about 32 psi and like 38 psi running. (both tanks tested)
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Cargo Master
Joined: Oct 2016
Posts: 2,738
Likes: 217
From: Northern VA
Does the needle drop sharply when punching the throttle? Does pressure drop under load? Really the way to do this pull codes, compression check, fuel pressure check, check timing, read manifold vacuum, smoke test for vacuum leaks. If that doesn't work you then begin component level testing with volt-ohm meter, plug wire resistance, TPS, IAC, CTS, IAT, keep going then you look for signal coming from PIP.
A bit of work but that is the right way to go about it. If you are more inclined to throw parts at it, The PIP commonly causes stumbling under load until it dies completely. Mine was so bad people were telling me the transmission was shot.
A bit of work but that is the right way to go about it. If you are more inclined to throw parts at it, The PIP commonly causes stumbling under load until it dies completely. Mine was so bad people were telling me the transmission was shot.
Tuned
Joined: Dec 2008
Posts: 318
Likes: 20
From: Upstate South Carolina
Does the needle drop sharply when punching the throttle? Does pressure drop under load? Really the way to do this pull codes, compression check, fuel pressure check, check timing, read manifold vacuum, smoke test for vacuum leaks. If that doesn't work you then begin component level testing with volt-ohm meter, plug wire resistance, TPS, IAC, CTS, IAT, keep going then you look for signal coming from PIP.
A bit of work but that is the right way to go about it. If you are more inclined to throw parts at it, The PIP commonly causes stumbling under load until it dies completely. Mine was so bad people were telling me the transmission was shot.
A bit of work but that is the right way to go about it. If you are more inclined to throw parts at it, The PIP commonly causes stumbling under load until it dies completely. Mine was so bad people were telling me the transmission was shot.
Laughing Gas
Joined: Nov 2016
Posts: 853
Likes: 62
From: Oxnard
MikeyMikeymike,
Not sure you saw my Thread post yesterday about the same problem you're encountering, so I'll quote on this post.
"Resolved my former stumble. My problem was a bad fuel filter, which I kind of suspected from the beginning. As I mentioned last month (May) I changed the normal tune-up components (spark plugs, Plug wires, Distributor Cap and Rotor) in preparation for the first fishing trip of the 2020 season. I had to store the truck while having a two truck garage built, truck had about 12 plus months of old gas in the tanks and for whatever reason I didn't add a fuel stabilizer, probably because from the on-set of storing the truck, I didn't expect it would 12 months. Incurred 12 months storage duration mainly because my City is difficult to get building plans approved (took three sets of plans revisions). So my problem was a bad fuel filter.
I checked out from work our fuel system test kit and at idle it read 30 PSI, at 1,200 RPMs it read 30 PSI and at 2,000 RPMs it read 31 PSI, which re-enforced my thinking of a semi-clogged fuel filter".
Hope yours is an easy detect and fix problem. I drove my truck into work today, first time since acquiring it back in December 2008 (it's not my daily driver), want to ensure It running without any lingering issues before heading back up to the mountains fishing next month.
Not sure you saw my Thread post yesterday about the same problem you're encountering, so I'll quote on this post.
"Resolved my former stumble. My problem was a bad fuel filter, which I kind of suspected from the beginning. As I mentioned last month (May) I changed the normal tune-up components (spark plugs, Plug wires, Distributor Cap and Rotor) in preparation for the first fishing trip of the 2020 season. I had to store the truck while having a two truck garage built, truck had about 12 plus months of old gas in the tanks and for whatever reason I didn't add a fuel stabilizer, probably because from the on-set of storing the truck, I didn't expect it would 12 months. Incurred 12 months storage duration mainly because my City is difficult to get building plans approved (took three sets of plans revisions). So my problem was a bad fuel filter.
I checked out from work our fuel system test kit and at idle it read 30 PSI, at 1,200 RPMs it read 30 PSI and at 2,000 RPMs it read 31 PSI, which re-enforced my thinking of a semi-clogged fuel filter".
Hope yours is an easy detect and fix problem. I drove my truck into work today, first time since acquiring it back in December 2008 (it's not my daily driver), want to ensure It running without any lingering issues before heading back up to the mountains fishing next month.
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New User
Joined: Dec 2016
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MikeyMikeymike,
Not sure you saw my Thread post yesterday about the same problem you're encountering, so I'll quote on this post.
"Resolved my former stumble. My problem was a bad fuel filter, which I kind of suspected from the beginning. As I mentioned last month (May) I changed the normal tune-up components (spark plugs, Plug wires, Distributor Cap and Rotor) in preparation for the first fishing trip of the 2020 season. I had to store the truck while having a two truck garage built, truck had about 12 plus months of old gas in the tanks and for whatever reason I didn't add a fuel stabilizer, probably because from the on-set of storing the truck, I didn't expect it would 12 months. Incurred 12 months storage duration mainly because my City is difficult to get building plans approved (took three sets of plans revisions). So my problem was a bad fuel filter.
I checked out from work our fuel system test kit and at idle it read 30 PSI, at 1,200 RPMs it read 30 PSI and at 2,000 RPMs it read 31 PSI, which re-enforced my thinking of a semi-clogged fuel filter".
Hope yours is an easy detect and fix problem. I drove my truck into work today, first time since acquiring it back in December 2008 (it's not my daily driver), want to ensure It running without any lingering issues before heading back up to the mountains fishing next month.
Not sure you saw my Thread post yesterday about the same problem you're encountering, so I'll quote on this post.
"Resolved my former stumble. My problem was a bad fuel filter, which I kind of suspected from the beginning. As I mentioned last month (May) I changed the normal tune-up components (spark plugs, Plug wires, Distributor Cap and Rotor) in preparation for the first fishing trip of the 2020 season. I had to store the truck while having a two truck garage built, truck had about 12 plus months of old gas in the tanks and for whatever reason I didn't add a fuel stabilizer, probably because from the on-set of storing the truck, I didn't expect it would 12 months. Incurred 12 months storage duration mainly because my City is difficult to get building plans approved (took three sets of plans revisions). So my problem was a bad fuel filter.
I checked out from work our fuel system test kit and at idle it read 30 PSI, at 1,200 RPMs it read 30 PSI and at 2,000 RPMs it read 31 PSI, which re-enforced my thinking of a semi-clogged fuel filter".
Hope yours is an easy detect and fix problem. I drove my truck into work today, first time since acquiring it back in December 2008 (it's not my daily driver), want to ensure It running without any lingering issues before heading back up to the mountains fishing next month.
fuel pressure regulator as it is the original and, after 25 years may be worn out although i did not detect any gas when the vacuum
line was disconnected. It figures i'd have this problem while on a vacation out of town. Will do these items when I get back home.
Hopefully I won't be on the side of the interstate waiting for a tow!
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tunafish
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