When I rev the truck it shakes?

Tiny
FORDSMB454
  • MEMBER
  • 1996 FORD F-150
  • 5.0L
  • V8
  • 2WD
  • AUTOMATIC
  • 180,000 MILES
My question is when I rev the truck it shakes and almost wants to shut off why. I just did a semi restore on it. Haven't checkd compression yet im sure its fine. I will check it its runing some what fine idles pretty okay, little rough new EGR, new gaskets, all around top and bottom end. I did lap the valves and valve seats. I reused the old valve they lookd fine 45 dgerees checkd them all look great so just lapd clean and valve seats are great. I got a code for p0174 I re did all the vacuume lines as well double checkd all those they are all seald and pluged in any help or thoughts would be very thankful thanks take care. Just to clearify again everythings stock and rockers valves springs and valve stem seals all stock clean and push rods lifters stock clean. Just did a lapin job and all new gaskets and cleand everything and also made sure the head gaskets are closed facing front so back of motor is open so coolant can work correctly to cool down block and enegine almost feels super over heated when im turning on for just 10 min ish any thoughts?
Friday, October 11th, 2024 AT 2:42 PM

15 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

The code indicates a lean fuel mixture. If you have checked for vacuum leaks and are certain there are none, the next thing would be to check fuel pump pressure. Here is a link that explains how in general it's done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

I attached the fuel pressure specifications below (pic 1). Also, pic 2 shows the most common repairs for the code you have. It shows an O2 sensor.

Here is a link that explains how to test the sensor:

https://www.2carpros.com/articles/how-to-test-an-oxygen-sensor-02-sensor

This is where I would start. Let me know your thoughts.

Take care,

joe

See pics below.
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Friday, October 11th, 2024 AT 8:16 PM
Tiny
FORDSMB454
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When I rev the motor the engine shakes badly I don't know what's going on.

Things I've changed/fixed.

Fuel pump : New
Fuel injectors : cleand not new
O2 Sensors : OLD
Engine mounts : New and Torqd
Vacuum Hoses : All checked no cracks or leaks that I can see
Fuel : New NOT old
Fuel Regulator : New
Fuel Pressure : 35 psi was 15 replaced fuel pump with New one
Gaskets : all new intake/lower intake/heads/exhaust so on

i did Lap the valves and check for leaks with water and a oil test No Leaks I have NOT checked compression yet after new fuel pump I could check that any help would be amazing thank you. Also here is a video to show.
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Monday, November 4th, 2024 AT 7:31 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

If the heads were off, we do need to check compression. Here is a link that explains how it's done:

https://www.2carpros.com/articles/how-to-test-engine-compression

Let me know.

Joe
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Monday, November 4th, 2024 AT 7:42 PM
Tiny
FORDSMB454
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Did a compression test all cylinders
cylinders no wet test just dry wide open throttle as well 7 cranks each cylinder
1. 120
2. 120
3. 150
4. 135
5. 120
6. 135
7. 120
8. 135
this my first rebuild on a small block 302 im almost positive this seems very low correct? I feel like they should be around 160-165? Each cylinder I think the valves are just too shot from these reading im assumeing the valves are just leaking. When I lapd the valves I did a oil leak test and water test no leaks but I understand this isnt very accurate just a close enough diy any thoughts? Or are these readings fine?
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Wednesday, November 6th, 2024 AT 6:17 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Are the rocker fulcrum bolts torqued to 18-24 ft. Lbs? If you over tightened them, that could allow a valve or valves to not seat. Also, Ford doesn't provide a specific compression specification. The only thing they offer indicates if the lowest and highest compression cylinders are within 25% of each other, it's okay. The specs you have are within that tolerance. However, the 120psi and 150 are at the max.

Joe
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Wednesday, November 6th, 2024 AT 7:03 PM
Tiny
FORDSMB454
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  • 42 POSTS
Ya I'm pretty sure there torqd I set valve lash on all.
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Wednesday, November 6th, 2024 AT 8:08 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Is there any smoke or odors from the exhaust? Also, if you have a live data scanner, could you let me know what the short term fuel trims are at operating temperature? Also, before starting it cold, check to see what signal the coolant temperature sensor is sending.

Let me know.

Joe
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Friday, November 8th, 2024 AT 7:46 PM
Tiny
FORDSMB454
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Ive unplugged the IAC valve when truck is on no change I also pulled the pressure feedback sensor no change pulled the EGR line and truck wanted to stall I'm guessing these 2 need to be replaced.
IAC valve.
Pressure feedback sensor.
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Friday, November 8th, 2024 AT 7:49 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Hi,

It is possible. However, the IAC valve's job is done once you press the throttle. At that point, air enters through the throttle body. With that in mind, I would start with the feedback sensor.

Let me know the results.

Joe
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Friday, November 8th, 2024 AT 7:55 PM
Tiny
FORDSMB454
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I bought a new IAC valve and pressure feedback sensor I installed them and it ran worse I put the old pressure feedback sensor back on and kept the new IAC valve on. It runs a little better but has got 2 codes p1409 and p1506 I'm assuming are for these? Still having issues though at idle shaking badly.
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Monday, November 11th, 2024 AT 8:21 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Hi,

The P1506 is likely an air leak. Recheck connections and hoses around the IAC. (See pic 1 below)

The P1409 is related to the EGR. Take a look at pics 2 and 3 and let me know if these are things you have already checked. If they are, let me know so I can move on to the next set of diagnostics.

Let me know.

Joe

See pics below.
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Tuesday, November 12th, 2024 AT 7:17 PM
Tiny
FORDSMB454
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Thanks for all this help I will check these. By chance I do have a multimeter should I also do a smoke test with a cigar and a pump just pump the smoke in check for leaks? And also, should I buy a hand vacuum pump? Would any of these help with these test or just a simple multimeter is fine?
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Wednesday, November 13th, 2024 AT 6:05 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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I would stick with the multimeter at this point. Just take your time and follow the steps. Let me know what you find once you finish.

Take care of yourself.

Joe
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Wednesday, November 13th, 2024 AT 6:09 PM
Tiny
FORDSMB454
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Okay, I checked all my electrical wiring except for fuel injectors but everything else ive checkd all reciving power no shorts checkd all fuses all checkd out inside and inside cab fuses all good I did find that 2 vacuum lines were backwords the TAD and TAB behind the block I switchd them so thats good now and I checkd the purge valve solenoid that is bad and also found that the TPS sensor plugs are bad there is 1 prong missing in both made video and will do check list to recap thanks again for your help.

IAC circut short to ground - good
IAC assembly stuck open - no
DAMAGED IAC assembly - no brand new
vacuum leaks - yes TAD and TAB were backwords switchd and fixd
damaged PCM - no
damaged throttle body - no
inlet air system cuts/leaks - no
any gaskets cuts damaged or leaking - no all new
PCV valve cracked or leak - no
Are any leaks detected in the above areas KE20 DTCP 1506 - TAD TAB switchd fixd everything else solid and good.

HE110 DTC 1409
all circuits checked except for fuel injector wiring.
IAC valve - solid
purge valve - solid
egr solenoid - solid
TPS sensor - damaged to my opionon video linked didnt bother checking missing prong
ac/heat blower - solid
wipers - solid
MASS AIR - checkd
mass air reader - checkd
coolant/oil sensors - checkd
ignition coil - check
solenoid resistant to purge was over 26-40 ohms so

HE100 EGR
EGR - brand new
Egr hoses - check no leaks
egr fully seated - check solid
egr gasket - new and solid
DPFE - not sure about has power to it but unsure of unit itself if its working or not

thats my check list so recap all wires are solid reciving power except for tps sensor in my opinon unsure TAD TAB vacuum switchd and fixd the purge valve solenoid is bad checkd everything else solid and havent turnd truck on after checking all this waiting for reply take care and thanks again for all your help
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Wednesday, November 20th, 2024 AT 5:37 PM
Tiny
JACOBANDNICKOLAS
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Hi,

The connectors only have three of the four pins used. There should only be three wires on each side.

It sounds like everything has been checked. Are you certain it is the engine causing the truck to shake?

Joe
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Thursday, November 21st, 2024 AT 6:17 PM

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