shano

hi all,
I've got a '94 Runner (6cyl) with a strange problem, hoping somebodys seen it (already searched the tech forum - no hits):

When taking off under a load in 1st gear I get a strong periodic "surging" effect - i.e. at a stop sign on an uphill, I take off and its like I'm stomping the gas pedal on and off. This consistently occurs from about 1500-2000rpm. After that, no problem. It never does it once I get into 2nd or higher gear. Occurs the same warm or cold.

Recently I had the valve cover gaskets replaced at a local shop. My rig was fine before this (except for the oil leak.) They fixed the oil leak but now I have this to contend with. They've examined it and say "nope, wasn't us." I have a strong suspicion they accidentally switched around some vacuum lines.

Am I best off taking it to the dealer to unscramble this mess?

Thanks for any clues you can provide.
-shano

4Crawler

iTrader: (3)

My guess would be some EGR vacuum lines were switched. Consult a Factory Service Manual for the proper connections.

NathanBERG

http://personal.utulsa.edu/~nathan-b...74layoutan.pdf
Let us know what you find.

shano

thx guys. I'll hammer on that tomorrow and post up if I can manage to correct it
-s

Mudcat

I am having a similar problem with my recently rebuilt engine. The vacum lines that go down the the power steering pump are broken off the fitting and I need to get a new one. What are these for? I have never seen anything of the sort on any other motors before. Could this be part of my problem?
Sorry shano don't mean to hijack but figured it was along the same lines.

4Crawler

iTrader: (3)

All they do is feed vacuum from the intake to the idle-up valve to boost idle speed when steering with the engine at idle. No problem to cap off the two lines where they leave the intake and connect to the idle-up valve.

Here's a shot of my 22RE with those lines capped:

Mudcat

Thanks, kind of what I had hoped.
Mine has actually smoothed out after some driving around today.

shano

so Mudcat - did you cap those lines, thus fixing the problem or did it just work itself out?

While performing standard tuneup on the rig this wknd (just to make sure it wasn't something utterly simple - it wasn't) I found a parted vacuum line which I repaired but neither the tune or vac line fix made any difference. So many vac lines - boggling...
-s

shano

so I finally took it back to the shop that swapped the valve cover gaskets. Explained the situation; the mech felt around and noticed the joint between the K&N Air system and the air-to-carb hose was ever so slightly NOT SEALED!
Duh... The opening was out of sight (of course!) and looked as though it was fine.

Once he found that and re-seated the hose over the air intake problem was solved. Jeez and I've been jerking around for 2 months with this.

Moral - start with the simple stuff and don't overlook what appears to be fine.
-s