Shaking

[cthdaddy]

I have a 94 escort, 1.9L, stick. During acceleration and at low rpm's my car will jerk on and off. At first I thought it might be the spark plugs. I pulled them and there OK, replaced the wires, new pcv and hose. Now I'm thinking it might be the clutch or transmisson. I had the clutch replaced 2 years ago. Any ideas?

Wayne, FORD lover

[mightymoose_22]

If not the plugs, maybe the wires... or perhaps it is the wrong type of plugs.

[Davescort97]

Check each cylinder to see if it is firing. You can do this by pulling the plug wires one at a time off the coil not the spark plug or you will get the you know what shocked out of you. If you pull a plug wire from the coil and the engine bogs down that cylinder is firing. If there is no change after pulling a wire that cylinder isn't firing. After isolating the cylinder that isn't firing replace the plug. If that doesn't help do a compression check. Could be a bad valve.

[notmeatall2]

Obvious things to check

Plugs - They seem ok u said. (Just incase remove them one at a time see if they spark make sure the screw thread is touching the block and be careful it hurts if u catch the spark.

Leads - If one or more of the plugs not work properly take each plug lead off one at a time and stick a screwdriver in the end and put it near the block (not touching this time) again be careful cause it can bite.

Distributer - remove cover and inspect for any signs of oil or dirt. (if it has one and is not electronically controlled.)

Alternator - check the voltage of the battery before u start the car. Should read about 12.5v and then again when u have car running. Should read 13.5v or above. max 14.5v - 15v.

[cthdaddy]

put in new plugs (Bosch platinum) shaking is gone. Now the only problem(had it before) the idle will fluctuate from 1500 rpm down to 500. When it goes down to 500 it almost stalls. When it warms up it's not as bad(1200 rpm to 500 rpm). When i stop (it's a standard, and in neutral) it will fluctuate 4 maybe 6 times then smooth out.
Thanks to everybody for the help

Wayne

[tripletdaddy]

The rpm issue may be the IAC if you have one. Try turning the steering wheel stop to stop while parked in neutral and foot on brake. I'd try this test adding more and more loads on the engine; the high beams, ac on high and high fan, wipers, rear defrost.... If it stalls, the IAC may not be working. If not...hmm Make sure all vac lines are good, tight and not cracked. Clean the MAF sensor using rated cleaner, clean the IAC valve, clean Intake Air Temp sensor if you have one. Do ohm check on the IAC and Throttle Position Sensor. Let us know what you find.

[frank58]

I am thinking you have 200k ? Please do a compression test, and vaccume reading.