Anybody know why my CPS got out of range ... I have to take the bolts out in order to advance the CPS enough for the engine not to die.

 

VE or VG?

sounds like the thing jumped time.

 

+1

I would be real interested in hearing exactly this discovery was made

 

VG30DE ... timing is good I just redid the heads and triple checked the timing.

When I try to advance or retract it works bad when I drive, but if I remove the two bolts and go beyond that It drives OK.

 

maybe your disty is off by a tooth, and can't be properly adjusted into range. have you used a timing light to check ignition timing at warm idle?

 

You must have screwed-up on timing the cam/cams relative to the crank - return the cps to stock and check on cam-belt installation/tension and make sure cams are both timed properly (there are usually locating marks on the belt for all 3 sprockets involved too)

 

Like I said I triple checked the marks and chains.

I checked the timing, ran the car, check the timing, ran the car and check the timing.

Could it be that I need to reset the computer ? I think there was some kind of procedure ...

BTW Don't have timing gun at the moment.

 

Perhaps I have my dunce cap on again, but VG30DE with a chain? ..............

 

lol o yea...

VG30DE was the Infiniti J30 and Z32 300zx motor... never came in maximas cuz it's too frigging big to fit under the hood

the one with chains is the one-of-a-kind VE and the belted one is the VG30E (as opposed to VG30ET, 33E, 33ER, 30DE, 30DETT etc)

 

My bad VE30DE

It's a 93 SE

 

oh.. well in that case your CPS is on the end of the engine and you don't have a distributor at all so what I said can't be the case.

so what youre saying is that the adjustment is so far off that if you adjust it to the max with the bolts still in place the engine will still die.. and that taking the bolts out for added adjustibility is the only thing that can keep it running?

what's the history of what you did to the car lately? why'd you redo the chains, how well did it run before, is it throwing any ECU codes, etc etc.

 

Yes exactly. I re-build the heads because of one of the VTC's cap broke off.
I Put the Crank on zero degrees TDC and matched the cams with the marks.

Don't remember seeing the check engine on.

 

Using this procedure?

 

Yes, same procedure.

 

If you did it correctly according to that recipe there can be no issue with the cps.

Are you sure you have the correct cams/sprockets in its correct position and that you haven't swapped eg LH and RH cams or sprockets?

Why are you so absolutely sure this is a cps/timing issue? ....... why did you start fiddling with the CPS in particular to sort the idling issue?

Vacuum leaks?
IACV?
MAF?
TPS?

Erm - a lot is said about 120 BTDC on compression stroke assembly in that manual - you quite sure about your Doesnt sound the "same" to me

 

Like I said TDC(Zero degree) on the Crankshaft and camshafts pointing to the marks. I ran and check the car twice to see when the oil goes up into the VTCs if there will be any change, but when I TDC-ed it the camshafts were still pointing to the marks. The 120 degree back is to make sure all the pistons are in middle position so any of the pistons don't touch. I put the R cams toward the passengers and the L cams toward the radiator. I have to add that you can't mess up the the cams because they are all different and will not fit if you mess 'em up - at least on the VE30DE.

I did the heads a week ago, and was trying to figure out ever since why when when I rev the car on spot it looks ok, but when I drive the car it runs like crap.

I took the bolts out because, while the bolts were on it work the best it could when I turn the CPS "all the way". And when I advance the beyond the bolts it's almost perfect - I'll need to get a gun to tune it best. But still this is not normal.

 

Damn I did everything the instructions in the fsm said like you. I hope I don't have this problem. whenever COURTESY FINALLY SENDS ME THAT KNOCK SENSOR SUB HARNESS! (2-3 week wait) Its already been 2.

 

I also re-did vacuum hoses, gaskets and seals. And did a grounding upgrade too. Got me injectors form a 98 nissan

BTW did you redo your VTCs ?

 

Not trying to bust your cahonies but as I said before, if the timing was done right, then the requirement to move the CPS away from its required position is not the answer to the crappy running problem under load.

So - "going beyond" entails what? - timing getting way more advanced or retarded?

When you say you got new injectors too, are they the same size/spec/flow-rate as the originals? If you have to advance the timing a lot to solve your problem (if you insist that the cam timing and mechanicals are correct) you may be sitting with a motor getting way too much fuel under load ......................

That sure is the complex answer but possible...........

I would think your next comment is going to be that the injectors are identical in spec, and if that is your contention, then your VTCs may be up the duff (even though new/rebuilt) causing incorrect valve timing under load..........

Its still really strange to me that you zoomed in on the CPS immediately to attack the problem while you are so confident that the valve timing is correct.

 

If the chain set-up on the VE's is anything similar to the VQ's then I have one question. When you say you triple checked the timing are you saying pre-assembly & starting it up, or have you pulled the covers back off since & rechecked. Because on the VQ's its easy to have it jump time when it fires up if a few important precautions aren't taken, despite staying in time when it was cranked by hand 1/2 assembled.

 

There was a thread on this not too long ago. Just do a search for timing you should be able to find it. When you're setting the timing, the best thing to do is mark the chains before you take the VTC's off, saves ALOT of hassle. And before you take off any sprockets, you have to make sure the engine is at 120 or else the chain will move. If you didn't mark the chains, then you have to keep rotating the engine until the silver marks on the chain line up with the dots on the sprockets, and there are 12 rollers between intake and exhaust "dots" (not lines on camshaft caps, you don't use those for timing). THIS HAS TO BE PRECISELY DONE or else your timing will be off. What happens is if it's off by one tooth, you will lose big power, if you're off by two teeth, then valves will likely meet pistons...

I would take the covers off and check your timing again. A pain, but at least you will have peace of mind. I did my rear VTC earlier this year, and made that same mistake where I was off by one tooth.

 

When I was taking the heads out I first set it to TDC and when I opened the Cams they were exactly on the marks - I made sure Crank didn't move until reassembly.

Unfortunately you have to redo prety much the whole engine to make it run. So because I re-did the VTCs I ran the car twice untill it warm up - to make sure the VTCs are full of oil before re-checking the timing.

There are couple of engines that have the same injector with the same part number, If I remember correctly one of them is VQ30DE and I pulled injectors from there.

I was asking the question here 'cause I know that the computer can advance the timing, because of a knock sensor. So is there a procedure to reset that ?

 

To answer your question from earlier no. I didn't replace my VTCs because before I disassembled the the motor they were running fine. So they should run fine after rebuild. I haven't done anything to them to make them change. (babied them) Plus I plan on eventually getting another VE motor and taking my time with rebuilding it and doing what I wanted to it. This one is just to get the car running po let it get subject o extreme heat. (cracked head gasket) Heads were barely re-usable.

 

Despite lots of people claiming intelligence to be built into the ECU, its as dumb as they come.

There is no evidence that the ECU is able to advance the timing in any FSM I have seen till now.

The ECU basically assumes that all is well on engine start and then either continue to control timing according to pre-programmed maps, or it causes a progressive and stepped retarding shifting of the whole timing map depending on whether knock is still present. If knock was present the last time the motor ran, the ECU soon forgets about that on engine switch-off - iow timing resets to the static and default map characteristics when engine dies. If the same knock condition exist after the engine is again started, then the ECU will simply again follow the progressive retarding strategy till no knock is present (assuming you have not screwed-up on the static timing setting).

This all happens because there is a need to cater for gaga fuel and high quality fuel without the owner having to reset the ECU every time he refuels.

Thus - the ECU has no built-in "memory" .............. its a stupid cluts.

 

To hell with it ... I had an extra CPS so sacrificed it and did a little modification. Now the car works great.

P.S. I don't use a gun, instead I use a voltmeter - something I made up. Just crank to 15 degree, hook the voltmeter b/w ground and the wire closest to the radiator and advance until you get 5 volts.

 

If you can't get your CPS to work in it's range of adjustments (assuming there is nothing wrong with the CPS), then you HAVE a timing issue. I wouldn't run that engine the way it is. And how did you come up with a figure of 5V?

 

+1

If not now, then soon enough you will be doing the heads again because of a burnt valve (in best case situation)

That does guarantee 15 degree static timing relative to the crank yes, but it doesnt guarantee proper mixture burning timing relative to the cams in your screwed-up situation.

Sort it properly - its worth the effort

 

I have a 1989 nissan maxima. It sat for 7 years, since ive had it i put on, new spark plugs, spark plug wires, K&N filter, Camshaft position sensor/Distributer, clutch, water pump, rear main seal, timing belt, tires, interior work, and exhaust. nothing major, just regular fix ups. When i got it after sitting, it appeared only the spark plug wires were chewed on by mice. Im having a very big problem with it tho. It starts fine, and the computer tells me code #55, meaning nothings wrong. When i drove it it missed and spit and had very little power, but sounded nice under 2000RPM. So i looked at it, I found out my injector was spraying in way to much fuel, i could smell it and that cylinder, plus 2 others were not firing. all 3 back cylinders run fine, but none of the front run at all. the far left front cylinder, i think #2, Was spraying way to much fuel, so i replaced the computer, later to find out it dident fix it, and plus my other 2 front cylinders, i think #s 4 and 6, werent getting enough fuel. i tested them, the far left front injector plug read like 13v, the other 2 read around 2.57v. all 3 back ones read between 11 and 12v. but the front 3 stay the same they dont change ever, to open and close. im getting spark, air, and fuel, i checked, throttle position sensor, grounds, emission control sensor, plugs, compression, intake, and they all turned out good. Ive seen on forums people have this same probllem, ive been trying to figure this out for a few months now, could you please help me or just tell me what i could do or need to do to fix this? Thank you very much, Robert Zeromski.