96 S10 NO POWER

I have a problem with my 96 S10 (vin X 4.3)

this is what's been done. The engine was rebuilt 25K mile ago. the fuel pump has approximately 40K on it. I just replaced the ignition coil. cap, rotor, wires, plugs, MAF sensor, and MAP sensor, the air filter, and the fuel filter. The truck runs like crap at highway speed, and stumbles, and has completely lost it's get up and go. I've used dry gas and injector cleaner in it, and it still runs poorly. I hooked up an OTC scanner to it and watched the readings. The timing jumps from -20 degrees at idle to -40 when under throttle.

I'm one match away from burning this truck... HELP!!!

Reply to
Roger Rabbid
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The stuff you replaced... you replaced w/ all new parts? or parts from another vehicle? If not all new parts, check all of the ignition components... check spark plug gaps, check ignition wires w/ multimeter, etc. good luck, bud.

-Mike

-- A happy kid behind the wheel of a 98 Mustang GT Cold air intake FRPP 3.73 gears Steeda Tri-Ax Shifter Full Boar turbo mufflers Hi-speed fan switch

255/60R-15 rear tires

Reply to
<memset

Everything is brand new. The problem started out as a stumble I was feeling at normal cruising speed, and has progressed to what it presentlly now it. I fear the problem is something in the fuel system.

Reply to
Roger Rabbid

I've had a pretty bad stumble under acceleration recently... it's been something that has haunted me in the past as well. Maybe... 4-5 months ago, I replaced all spark plugs with new Ford Motorcraft Platinum plugs. Stumbling was gone 100% for a couple days... then came back. I checked spark plugs & gaps many times. Each time I did, stumbling went away for a day roughly. I then replaced ignition wires with Ford Motorcraft 8mm wires... problem went away immediately & stayed gone until very recently... when I said screw it, got out my wallet, and bought NGK Iridium spark plugs ($7/plug, compared to $2/plug for Ford Motorcraft Platinum plugs). Gapped & installed 'em... 0 stumbling. Nada. Zip. Zilch. The stumbling would occur under any type of acceleration, but most commonly during low RPM's (and I mean if I barely touched the gas pedal or went full throttle). Ah well. HTH.

-Mike

-- A happy kid behind the wheel of a 98 Mustang GT Cold air intake FRPP 3.73 gears Steeda Tri-Ax Shifter Full Boar turbo mufflers Hi-speed fan switch

255/60R-15 rear tires

Reply to
<memset

The things that often work to fix a ford don't always work on a Chevy. The induction systems are different, especially where my S10 is concerned. It's an entirely different injection system than what you might find on a 302 or one of them 4.6's or 5.4's

Reply to
Roger Rabbid

Ignition problems can cause stumbling on any sort of engine though. Worth looking.

-Mike

-- A happy kid behind the wheel of a 98 Mustang GT Cold air intake FRPP 3.73 gears Steeda Tri-Ax Shifter Full Boar turbo mufflers Hi-speed fan switch

255/60R-15 rear tires

Reply to
<memset

. . =3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D snipped-for-privacy@comcast.net (Roger=A0Rabbid) . I have a problem with my 96 S10 (vin X 4.3)

This is what's been done.

The engine was rebuilt 25K mile ago. The fuel pump has approximately 40K on it.

I just replaced the.... ignition coil cap, rotor, wires, plugs, MAF sensor, MAP sensor, air filter, and the fuel filter.

The truck runs like crap at highway speed, and stumbles, and has completely lost it's get up and go. I've used dry gas and injector cleaner in it, and it still runs poorly. I hooked up an OTC scanner to it and watched the readings. The timing jumps from -20 degrees at idle to -40 when under throttle.

=A0=A0I'm one match away from burning this truck... HELP!!!

=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D When you had the OTC hooked up..... What was the STFT and LTFT readings? What did MAP frequency look like? Did the O2 readings look good? O2 cross counts? TPS readings? NO CODES?

answer the above.... or.....

Check compression.

Check vacume at idle and under cruise, pay attention to needle fluctuations AND readings. Check exhaust for excessive backpreasure.

Check alternator output.

Check for good ground connections.

Check the ignition module and pickup.

Check the Temp Sensor.

Check the O2 Sensor.

Check the TPS.

Check the IAT sensor.

Test, remove, inspect, and clean the IAC and the EGR, or replace, and go for another test drive.

Test fuel flow rate and preasure at high rpms.

Check the ECM.

repair or replace as needed, or post results for further help. Feel free to test in any order you see fit.

respectfully submitted for your consideration, ~:~ MarshMonster ~passes you a box of Diamonds~ =3D=3D=3D=3D=3D =3D=3D=3D=3D=3D

Reply to
Marsh Monster

Here's what I have done thus far. Replace plugs, wires, cap, rotor, MAP sensor, MAF, fuel filter. I cannot get a timing reading off the harmonic balancer unless I keep retarding the strobe until the mark comes up on TDC. I'm at the point where I'm going to remove the timing cover to see if I've got the timing gears out of alignment. As of today, and the last test drive I took, the engine runs perfectly, and there's no more skip like I was getting. Before, full throttle would result in the engine skipping at high rpm, and the code would pull a random misfire. I changed the plugs today, and it seems to have cured it of that (for now) My problem is just engine lazyness, like the timing is too retarded. The clutch converter is now staying locked at highway speed like it should. Yesterday I had the fluid and filter changed, but it inself didn't cure the no lockup condition I was getting before I changed the plugs today. The truck runs like the cat is clogged. I'm certain that it's not the problem. The engine has just become lazy.

Reply to
Roger Rabbid

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I'll double what MM said, check fuel pressure, preferably while going down the road under load. If you have the $ to replace all those sensors, you could buy a $30 pressure gauge. Oh and like MM said, check voltage at the battery while running=*very* easy test........(just got the feeling you weren't listening the first time:) Does it ever run good on the highway?

Reply to
Scott M

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