Weird hickup on 97 1500

97 1500 5.0L. When I am going between 40mph and 45mph in 4th gear and the RPM's are at there lowest, I get a weird hesitation/jerk/stumble/hickup or whatever you want to call it. I am not sure if it is a misfire or not. Other then that it feels pretty decent and idles fine. It seems too do it when I am staying a constant speed within this mph range. Anyone have a clue what this could be? Plugs and wires are only about a year old.

Do you get a check engine light on at all?

Go to Autozone and have them check for codes, they do it for free. Post any codes.

How many miles?

Have you looked at the rotor and distributor cap?

No engine light and no codes. I have not pulled the cap and rotor. 160000miles.

Fuel filter?

Fuel filter is about 6 months old, its a wix.

Throttle Position Sensor or EGR?

Check plugs for fouling from bad head gasket. Mine does the same thing and has a bad oil leak into 3 of the cylinders.

Ok, figured out it has a random miss on number 6 according to the scanner. I pulled the plug. It had a little bit of oil on the threads. Not much though. I cleaned it up and put it back in. Also, I changed its wire. I'm still getting the miss. Any suggestions?

Distributor gear wear can show those symptoms. Improperly set distributor can too. With my truck it was at speeds over 40 with very slight pressure on the gas pedal, sometimes a misfire would register and sometimes not. You need a scantool that will show the parameter cam retard or camshaft offset- the difference between the CKP and CMP signals. Yours is probably negative by 8 degrees or more(probably not -15 degrees or you would have a p1345 code)

my truck seems to be doing the same thing. I thought it was the cam position sensor, changed it, same thing. Cant figure it out. :banghead:

could the crank position sensor cause these symptoms??

All of my ignition stuff is new as well: cap, rotor, plugs, wires, and the cam
position sensor.
Its really weird, when you stomp on it, it goes, but at cruising speed, it bucks.
Sorry if I should have posted a new thread, but any help appreciated.

I know my cam is at 0 degrees, I made sure they checked that. Taking it down to another shop today to see if we can figure out the problem. I might be wrong, but I don't think its the distributor since its just on number 6, but who knows. Funny thing about it is that it only does it under certain rpms. Sitting idle or acceleration is great, just that damn low rpm cruise. I drove about 30miles to get some steelie fishing in today and it bucked about 6 times. I assume that if it was major it would do it more then that?

How did they check the cam retard?

Well the second shop showed me the cam retard is at -12. That makes me mad, since the last shop said it was fine. So my guess is that the distributor is just off or the crank or cam sensor is off. Gonna adjust it in the morning and see if it holds. Will let you know.

If you haven't messed with the distributor or had an intake manifold gasket replaced, the distributor should be pulled to check the gear. Some gears have worn almost to the point of failure. You need a scantool and have to rev the engine over 1500 rpms to adjust the cam retard. You need to turn the distributor counterclockwise to compensate for negative cam retard

Actually, the distributor was pulled a month and a half ago because of the intake gasket failure. I took it too the shop because I don't have a computer to set the cam retard. Find out that they did not set it correct so it was a complete waste doing it that way. Should have just done it myself and taken it in to set the cam.

It was certainly the cam retard. Have it set to +1 and is running great.