QuestionI asked you a question in February about my truck and you were nice to respond. Since then I have had 4 different mechanics look at it.The suggestion you made regarding the distributor being contaminated with oil has not panned out.It was replaced but it still jerks. I broke down and brought it to the dealership. They said it was my fuel pump but changing it did not solve the problem. Now they are saying I am missing a timing chain guide and that is causing my problem. My questions before I put anymore money into the truck (1990, 130,000 miles, bought it new, never recked, oil changed regularly, ran great before this issue)are...
*Does the timing chain guide sound like a possible solution?
*Could driving the truck with this problem have caused other problems? valve issues?
*Do you think is is worth fixing?
Thank you for your time, Sincerely, Scarlett Nakajima
This was my initial question to you
1990 Nissan Pickup Jerking
Question Thanks for your input in advanced. My truck jerks with acceleration primarily in the first three gears. It is as if a new driver that doesn't know how to shift is driving. My mechanic has checked the distributer, timing chain, fuel for water, and something else I can't remember. He can't figure it out. Also, don't know if it is related but it is having trouble starting on occasion. It doesn't sound like a bad started to me and my mechanic changed battery and 'tightened a loose starter wire' but that didn't help.
Answer Scarlett,
It sounds to me like the distributor is contaminated with oil on the optical pickup and shutter wheel. Have the mechanic disassemble the distributor. This is pretty easy and it does not even have to come out of the truck. Remove the cap, rotor, rotor post and cover and under the cover you will find a round disc with slots along with the optical pickup. There is probably oil contamination and that causes the miss and hard start condition you describe. So, have it checked out and email me back. The fix is a rebuilt distributor. If the engine has excessive blowby as in it uses a little oil that would mean that it is contributing to pushing oil up the distributor shaft and through the oil seal. A corrective fix here, other than re-ringing the engine, would be to change to Penzoil 5W30 along with a pint of Restore engine additive. The combination should help compression and reduce blowby to keep the new distributor from getting oil contamination.
AnswerScarlett,
Usually the problem with jerking is either spark, like the distributor you replaced, or fuel like the fuel pump the dealer replaced. If the chain guide is missing where did it go and why would it run good until now if it had a missing chain guide. Now, if the chain is stretched and the guide is worn nown that could cause erratic timing. But, I would not see that this would be the cause of your problem. A good truck in nice shape is always worth a repair. What I would do first is get the vehicle diagnoses. Most shops and dealers are not into finding problems and since yours is pre-on board diagnostics they can't just plug into your computer and see the problem. You need a shop with an engine analyzer and possible a dyno to do the test on to see what is going on. The problem is either fuel or spark and is most probably sensor related. Find a shop that will do this and you should find the problem. I would do this before I spent any more money on the truck and that includes the timing chain.
