91 replies to this topic

[J-MAN]

Finally installed my Delta 272 cam on Friday and drove the car around and it felt absolutely wonderful (broke the cam in by revving between 1.5 and 3k for 25 min also made sure my cam timing was at TDC during the install), the car had more power in the mid range and top end and I was extremely pleased with my first camshaft installation. Unfortunately i didn't adjust the valve lash and had alittle bit of valve chatter, so today after school I decided to take it all apart again and adjust the valve lash. While adjusting the valves I took my time and set the intake valve lash to .008 and the exhaust to .010 within the specs of the service manual. I also followed every step of the manual including the the order for adjusting the valve lash (1,3,4,2). Put it all back together and started it up. Oddly enough the idle was lumpier (as i assumed it should be with a more aggressive cam) but much much lower than normal considering its 40ish degrees out which is normally 2000ish rpms, and it idling in the lower 1000's. Ignoring this as a symptom of the new cam with proper lashing I pulled out of the driveway and eased down my block and upon letting off the throttle and stopping from 15-0 mph at the stop sign the car just died and the battery and oil light came on. Extremely nervous I cranked the car a few more times but it only started for a few seconds then died so I got out of the car and checked the oil which was well within the norms and let the car sit for a few minutes then started it again and made it back to my driveway apron where it once again died, so I pushed it up the driveway and summoned my father (E-Man) from his slumber. He came outside and we hooked up the battery tester and it read 12 volts which is also fine. We started the car again and it ran for a maybe 30 seconds with the newfound idle problem and upon revving to 2000rpm and letting off the gas the car died on its return to idle. What could possibly be wrong my fellow RPR members? Should try adjusting the idle speed? I also did not remove the spark plugs when i was turning the motor to TDC for each cylinders valve lash, is it possible I fouled them? Someone please help me asap as I need the car to get to school on Thursday.

Thanks,
J-Man

[J-MAN]

Finally installed my Delta 272 cam on Friday and drove the car around and it felt absolutely wonderful (broke the cam in by revving between 1.5 and 3k for 25 min also made sure my cam timing was at TDC during the install), the car had more power in the mid range and top end and I was extremely pleased with my first camshaft installation. Unfortunately i didn't adjust the valve lash and had alittle bit of valve chatter, so today after school I decided to take it all apart again and adjust the valve lash. While adjusting the valves I took my time and set the intake valve lash to .008 and the exhaust to .010 within the specs of the service manual. I also followed every step of the manual including the the order for adjusting the valve lash (1,3,4,2). Put it all back together and started it up. Oddly enough the idle was lumpier (as i assumed it should be with a more aggressive cam) but much much lower than normal considering its 40ish degrees out which is normally 2000ish rpms, and it idling in the lower 1000's. Ignoring this as a symptom of the new cam with proper lashing I pulled out of the driveway and eased down my block and upon letting off the throttle and stopping from 15-0 mph at the stop sign the car just died and the battery and oil light came on. Extremely nervous I cranked the car a few more times but it only started for a few seconds then died so I got out of the car and checked the oil which was well within the norms and let the car sit for a few minutes then started it again and made it back to my driveway apron where it once again died, so I pushed it up the driveway and summoned my father (E-Man) from his slumber. He came outside and we hooked up the battery tester and it read 12 volts which is also fine. We started the car again and it ran for a maybe 30 seconds with the newfound idle problem and upon revving to 2000rpm and letting off the gas the car died on its return to idle. What could possibly be wrong my fellow RPR members? Should try adjusting the idle speed? I also did not remove the spark plugs when i was turning the motor to TDC for each cylinders valve lash, is it possible I fouled them? Someone please help me asap as I need the car to get to school on Thursday.

Thanks,
J-Man

btw car is devaced if that helps at all with the diagnosis

[crx 87 no hood]

you may have bent valves but check the valve lashing cuz they can come loose !!

[EuphoricBlue]

btw car is devaced if that helps at all with the diagnosis

Your vacuum advance is hooked up still, right? How do you have it hooked up?

I suspect it ran OK before and not after because it didn't open the valves as high with the lose valve lash.

My theory is that when you tightened it up it made the valves open more, which decreased your intake velocity around the valves. This in turn makes it harder to get a good A/F mixture and in effect you are now running leaner at idle which lowers your idle, could be to the point of stalling.


PS: You should probably remove the duplicate topic (link), it's only going to make things confusing later.

[jsgprod]

btw car is devaced if that helps at all with the diagnosis

I have two questions about this.
1. When did you de-vac the car? Before you changed the cam and did it run OK after that? Or was this done at the same time you did the cam change?
2. When you removed the big black box on the drivers side fender, did you take the IMA out of the box and re-connect it to the wiring harness? If you are still running the original ECU the IMA is necessary.

FWIW, the IMA is the Idle Mixture Adjuster...sounds like it may be related to your issue.

[J-MAN]

I have two questions about this.
1. When did you de-vac the car? Before you changed the cam and did it run OK after that? Or was this done at the same time you did the cam change?
2. When you removed the big black box on the drivers side fender, did you take the IMA out of the box and re-connect it to the wiring harness? If you are still running the original ECU the IMA is necessary.

FWIW, the IMA is the Idle Mixture Adjuster...sounds like it may be related to your issue.

Car has been de-vacced for years and was done so by the previous owner, and the car ran perfectly fine prior to the valve lash adjustment ( with the stock cam and with the new cam). Car is running the original ecu so I'm assuming the IMA is still hooked up because it ran fine in the past. Hopefully I dont have any bent valves, and considering the car has 30xxx miles on the rebuilt motor I'm really hoping this is not the problem. Could it be possible that the car is running leaner at idle so maybe I should fiddle with the Idle control screw? If so should I adjsut the one on the throttle body of the other one?

hope this helps with a diagnosis,
Jon

[RARECRX]

Well I have to ask this. Did you adjust the valves when cold or hot? and also is your feeler gauge in MM or inches? I had a friend make this mistake and adjust to MM instead of inches. If it was running fine before the valve adjustment, I would suspect that has a lot to do with the problem. Maybe you were not fully TDC? I would rinse and repeat.

[J-MAN]

Well I have to ask this. Did you adjust the valves when cold or hot? and also is your feeler gauge in MM or inches? I had a friend make this mistake and adjust to MM instead of inches. If it was running fine before the valve adjustment, I would suspect that has a lot to do with the problem. Maybe you were not fully TDC? I would rinse and repeat.

Just was outside doing precisely that to make sure it wasn't a major screw up on my part. Rechecked all the clearances cylinder by cylinder and they were perfect. Valves were adjust cold and rechecked cold after sitting overnight. Any other ideas rpr?

Jon

[J-MAN]

Just went out to try the car again. Started up on first try but idle started out about 1000 then rose to 2000 (normal for this weather), after sitting for a few minutes to warm up the cars idle returned to approx 1000k but was unsteady, jumping from 800-1200ish then slowly but surely the car died. Does this sound like an idle issue or more serious? Possibly a fuel filter issue? Jon

[RARECRX]

GULP.I might have to break out the "Scott" on this one... Double check the cam timing.. Make sure it is at TDC and check position of the cam gear. This and if you adjusted the valve wrong and it hung open and bent would be my last resort answer. Really I'm guessing cam timing on this one. AHH DAMN I SAID IT. Now I will get old and bald. It may "seem right" but double check.

[jsgprod]

Just went out to try the car again. Started up on first try but idle started out about 1000 then rose to 2000 (normal for this weather), after sitting for a few minutes to warm up the cars idle returned to approx 1000k but was unsteady, jumping from 800-1200ish then slowly but surely the car died. Does this sound like an idle issue or more serious? Possibly a fuel filter issue? Jon

Did you ever check that filter in the fuel pump inlet?

I know I'm going against the common theme that is developing here but I have to say this. Having your cam timing off one tooth is not going to cause the engine to have the high rpm rev limiter (as you have called them) type issues that you're having. Advanced or retarded, it will definitely affect how the engine runs no question but the car will still run to 6500-7000 rpm in all the gears AS LONG AS EVERYTHING ELSE is working properly.

I've even had one of mine off by 14 degrees once (advanced in case you were wondering) and it made over 100 hp! Ran pretty damn good too but I knew something wasn't right.

Sounds like you still have a lot of items you need to be checking on.

Jay

[J-MAN]

Well took out plugs to check to see if they were fouled, luckily they are not, but plug hole #1 was cross treaded by the previous owner so working on putting that back in. Reset the cam timing as well. I still don't understand how adjusting the valve lash could make the motor have this issue, it ran perfectly before hand minus a little valve chatter.

hopefully I'll get the plug hole fixed so i can even see if this is a cam timing issue or if my troubles are coming from elsewhere,
Jon

[Lymitliss]

First question, do you have a tuneable fuel system? Delta cams claims that for the 272 (the sportier of the 2 options) you need a fuel system that can be tuned/adjusted to run that cam. He also said you need it because the manifold pressure is way too low with that cam for the sensor to compensate for...something to think about.

Also, if it had a bent valve would it really run smoothly as it's warming up? I would think it'd run like shit the entire time and probably sound funny.

Also, something someone else suggested, if it's not getting enough gas, I would think it would make sense it would die at regular idle but not at the 2,000rpm warmup due to it running rich to help it get warm...

[J-MAN]

When I spoke to the guys at delta they said it would be a drop in ordeal and wouldn't really require too much adjustment (which I found a little odd). As of now the car has integra injectors on a stock SI ecu with an adjustable fpr. As I stated earlier the car ran perfect prior to the valve lash adjustment and i drove a good 50-60 miles like that with no changes to timing fuel pressure idle control or anything, hence my confusion with the current predicament with the car.

Thanks for the responses rpr, keep em coming,
Jon

[Lymitliss]

All I know is that both guys I talked to at Delta cams said you need tuneable fuel systems. I'm not trying to argue with you, that's just what they told me when I called about getting one for myself. Supposedly the street version drops in, and the 272 you have is a sportier version that needs a better fuel setup. Take from it what you will, it very well may be some other problem, I really don't know.