timing HELP

[thechad]

What doies the car do if its Off by one or two teeth?

 

[BoostActionBob]

the vehicle may make a weird noise and not run very well. it will get very bad gas mileage. its a very good idea not to drive it or even run the engine till it is timed because 4G63's are intermittent engines. Which means if your timing is off you will have a bunch of other problems unless the car gets timed. Head problems. ex. valves, lifters, pistons if bad enough. please go into detail of what your vehicle is going through.

thanks

 

[thechad]

I just did a rebuild with flow coated head cometic gaskets and t28 combined with an evo III manifold. New timing kit with the greddy extreme belt. Thought timing was right but it idles very rough. When started it revs to 2500 and then drops to 500 and then stalls out. After 5 to 10 minutes of this it will maintain idle at 750 but sputters and powert is not up to normal. Compression was 152 all theway across and held boost for over 30 seconds, new plugs and wires. im lost

 

[92redman]

Not sure what an intermittent engine is(maybe it's an engine one minute and the next it's a money pit?). They are interference engines, but one or two teeth off at any of the gears should not cause interference unless you maybe have a stuck lifter. If the crank is off a couple of teeth, it probably skipped ahead, so you would have retarded intake and exhaust cam timing. Depending on if it is a cam, which one it is, and which way it is off you may see some performace enhancement or loss along with crappy idle, low vacuum and bad gas mileage. If the oil pump is off, you will have an engine vibration.

 

[92redman]

I just did a rebuild with flow coated head cometic gaskets and t28 combined with an evo III manifold. New timing kit with the greddy extreme belt. Thought timing was right but it idles very rough. When started it revs to 2500 and then drops to 500 and then stalls out. After 5 to 10 minutes of this it will maintain idle at 750 but sputters and powert is not up to normal. Compression was 152 all theway across and held boost for over 30 seconds, new plugs and wires. im lost

Did you happen to take the crank trigger plate off when you did the belt? Not sure about 2g, but on a 1g engine you can install that timing plate backwards and get symptoms that you are having. You basically set the cams right but set the crank off I think 10-15 deg. You need to pull out the number 1 plug and set the engine on TDC using a long screwdriver or the like to determine when the piston is really at TDC. Then see where your timing is at.

 

[thechad]

what about the revving up and droppping down and stalling but then holding idle?

 

[thechad]

no i did not remove the crank trigger.

 

[92redman]

Is it still running pretty rough when idling?

 

[BoostActionBob]

hahahaha i feel like a tool thanks for corecting me on that one red. dont know why i said intermittent. but you took care of it. thanks

 

[thechad]

It holds idle between 700 and 800 but sputters like a big block v8

 

[92redman]

Okay, after reading your description again, it's not likely that it's related to the timing belt. It looks like you are saying that it reved on it's own to 2500 and then stalled out, correct? I was thinking that you couldn't rev past 2500 and it died when you let off.

There seems to be a piece to the puzzle that is missing, as usual. It's probably something really dumb that you are just not giving enough or the right information to figure it out. What exactly have you done, and what have you checked/tested/looked at so far?

 

[oldman]

Not sure what an intermittent engine in(maybe it's an engine one minute and the next it's a money pit?).

That's too funny.

 

[BoostActionBob]

just throwing this out there. isc,

 

[thechad]

When it sits on its own it revs to 2500 and drops to stall out. IF i give it some gas and ther engine warms up it will hold idle.

 

[BoostActionBob]

That's too funny.

i agree and it was me! hahaha

 

[thechad]

wouldnt the isc not work all the time and not just at start up

 

[92redman]

Does the check engine light come on? Have you double checked all electrical connections such as MAF? Here any unusual air rushing/checked for any large vacuum leaks such as a brake booster hose not connected? Do you have a datalogger to look at sensors and fuel adaptives/o2 volts?

 

[thechad]

Had a head off of a 95 talon turbo rebuilt and flowcoated. Put on head with all new cometic gaskets, arp studs, t28 turbo on evo III, manifold, complete timing kit with greddy extreme belt. New plugs and wires have checked out. Compression is at 152 all the way across and held boost test for over 30 seconds.

 

[thechad]

check engine light came on with egr code and a po3ff which was a junk code. Cleared codes and i just got the datalogger so Im not very familiar with it.

 

[BoostActionBob]

i had a bad isc and i could start it up and it would do the same thing yours did. i would drive it for a while and stop at a light and think everything is all good because it didn't idle surge. changed the isc. it would idle at about 900 rpm and as it warmed up it would be right at 700.

 

[thechad]

would this cause the sputter and how much does this piece cost?

 

[92redman]

What datalogger, it would be nice if you could get a crash course on monitoring sensors and taking logs to post.

 

[thechad]

ive got a palm pilot with the palm n stein software off of ebay. i learned to pull codes and from the monitoring I figured out how to view rpm and ignition timing.

 

[92redman]

Have you figured out how to look at 02 trims and O2 volts? I would be curious to see what the O2 sensor is seeing and how the ecu has corrected, when it is idling of course.

 

[thechad]

o2 volts said 0.003 and never moved. I dont know what this means and would a bad o2 cause all of this? WHat about some sort of vacuum miox up or something, I doubt that happened but i cant rule it out.