Slow89Iroc-Z

I just installed the cam, heads and stealth ram in the sig. I lubed everything well during assembly and tryed to start it. Well I had the distributor 180 degrees off and it backfired through the exhaust. Turned the distributor and dropped it back in and it fired up. However the engine sounds sick and is extremely ruff at idle and it smooths out off idle but lackes a lot of power it seems. I have a custom bin that was made by a member on this board who has the exact setup as I and assumed it would be close enough to drive. I played with the idle air control and TPS and timming and nothing seems to smooth it out. When I disconnect the black/tan wire to set the timming it is still real ruff.......I am running out of ideas.... Fuel pressure is at 45psi and timming is at 8 degrees....please help. I am going to try and readjust the valves tomorrow to see it it helps........

89ProchargedROC

check for vacuum leaks

John Millican

iTrader: (1)

Pull any codes?

Otherwise I would suspect that "custom prom" and get one done yourself.

89BlueTA

Did you double check that all the plug wires on correctly? It is very easy to switch a couple of them.

nick

Slow89Iroc-Z

Double checked all vaccuum lines and plug wires are correct.........what else could cause a bad idle but good part throttle driving.......the motor really shakes and the idle jumps around about 100 rpm....

Mkos1980

iTrader: (8)

dude i have every mod like you minus the S Ram and on the stock chip my car idles fine. a friend burned me one and the car ran like crap slapped the stock one back in and the car idles great.

mystikkal_69

iTrader: (2)

that whould be my suspect, the prom. i burned a prom and the damn car wouldn't idle right. i put the stock on in it ran fine. then i re-burned the prom and the it ran great.

Slow89Iroc-Z

Could there be something mechanically wrong???? I need help....

89ProchargedROC

put back in the stock prom and see if that works....if you dont have one....

let me know. i have a spare computer with prom for a MAF if you need one

Slow89Iroc-Z

I tried using the ARAP prom with no changes other than injector constant and it has no effect at all. I have the prom burning equipment but am waiting on a cable to link to the computer. Anyone live in the south Chicago suburbs near Burbank, oaklawn, justice, brideview, alsip....etc...... I need help I cant figure this out!!

IROCZ88

With a bigger cam you pull less vacuum at idle which can make a fuel injected motor run like crap. My suggestion would be use VEmaster to quickly and roughly tune your VE tables and go from there.

IROCZ88

Nevermind, I just noticed you have MAF. I would consider a switch to SD because it gives you a lot more tuning options.

Mkos1980

iTrader: (8)

True on a 90 and later with a SD system but running a MAF Vacume really isnt an issue. I run the same cam and heads on the stock chip and my car runs and idles great.

Grim Reaper

Change your intake, and you'll find your car runs like crap. If you hook a scan tool to it, I seriously doubt you are running 128/128 perfect, but it's probably not bad enough (yet) to hoop you.

I agree with John Millican, you need to get your eprom figured out. If you are running too rich or too lean, it will run like crap ESPECIALLY when in open-loop, which is generally when you start a car and just leave it idle. MAF or SD, they both have their limits and do need to be tuned if you want it to perform optimally.

PS: SD is a lot easier to tune than you think. Don't let people tell you differently. And you can convert to SD a lot EASIER than you think (less than 1 hour to repin the connectors including splicing a MAP sensor into the leads to the soon to be obsolete MAF sensor). But I prefer to recommend people convert to SD when their MAF sensor or their 165 ECM dies. I am finding that the 165 MAF ECM is getting harder and harder to find in wrecknig yards (I would never buy one new) while the SD 7730 is a dime a dozen (GM used the 7730 in SO MANY vehicles, they will probably be available for 100 years).

Slow89Iroc-Z

OK......before I go switching ECM's I need to get this running right....its backfires through the intake when the throttle is hit and released at idle. I will almost die when put in gear....and the engine runs so ruff the car shaks like mad.......

StocRoc

iTrader: (1)

could be wrong, but sounds to me like the valves are adjusted wrong. one time I had a buddy that "new what he was doing" adjust my valves and my car did the same thing. It would shake badly and pop through the exhaust. I believe he had them to tight and the exhaust valves weren't closing all the way. I've heard you can burn up a valve this way, so I would check it out

Grim Reaper

Have you set your base timing (with the EST wire disconnected to 6* BTDC)? Have you double checked your firing order and have you adjusted the IAC. Sorry for stating the obvious, but you haven't stated ALL that you have done and not done.

So you have to start with the basics and make sure the engine is "mechanically correct". Once it is mechanicall correct, you SHOULD be able to make it run "half-assed" with the ARAP bin. It MAY not be optimal but it should be smooth.

If you have an MSD box, double check it. A buddy had a "rough running engine" which I could tune "half-assed" but it definitely wasn't right. Turned out it was his MSD box...the spark was bouncing all over the place when the EST wire was connected...looked fine with the wire disconnected.

You don't need to go to SD to resolve the "smooth running" issue. You should be able to run "smoothly" with the MAF setup (well, as well as you can with the Hot Cam). One advantage with SD, you can use the MAP sensor to verify any vacuum leaks. But if you pull a vacuum lead (like the fuel pressure regulator) it SHOULD make the engine run worst. If you notice nothing, then it may suggest a vacuum leak. Make sure you gently rev the engine though.

By any chance do you have a scan tool?

89ProchargedROC

Sounds like you either have the valves adjusted wrong or the distributor in wrong

JucinGTA

I never even thought of that, I am going to have to go with the Valve adj. I had the same prob and didnt even think of it!!

jichniow

I second the adjusting the rockers arms!! It drove me nuts for two days on a new engine build up.

While you're at it make sure all the vacuum lines are in good shape, plug wires and plugs are all good. If you have any doubt about the new prom just put the stock one back in. I've got a 218/224(@.050) 112LSA cam and it runs fine on the stock prom. It runs better with the other proms I've put in but that's an easy way to eliminate that possible problem.

Slow89Iroc-Z

I will adjust the valves again tomorrow..... Am I right to adjust them till they stop ticking and then tighted 1/2 turn more.....or should I go a 1/4 turn? I am replacing the wires now with MSD 8.5mm Super Conductors because I was seeing some arcing down by the plugs. I also replaced the ignition module since I had it apart and it was the original piece. It is real tight back by the distributor with the Stealth Ram. Man I am about had it with this thing!!!!

88 WS6 TransAm GTA

iTrader: (1)

1/4 to 1/2, its really up to you. I usually do 1/2 turn, just make sure theyre all done approx. the same, and youll be good to go.

89ProchargedROC

Honestly...its whatever the engine is happiest with

Slow89Iroc-Z

The base timming was set with the EST disconnected to 8 degrees and the chip was changed to 8 degrees initial timming. The firing order has been checked many times and the IAC was adjusted but it had little effect on idle quality but adjusting the IAC had an effect on idle speed....the TPS was reset to .54 volts after the IAC was set everytime. If a vac line is pulled the idle gets noticably worse. I put the stock AUJL bin in the car with only the injector constant changed to 32 to reflect my Ford SVO injectors and no change in idle. I tried the ARAP with the injector constant chaged and idle was the same. I used the custom prom and the idle was the same. I do not have an MSD box only the coil. I am working on putting together a scan tool using Craig Motes software, but I am have trouble locating a link at a decent price. The valves were set with the engine at rest before start up by turing the nut on the Crane RR till resistance was just flet on the pushrod and then 1/2 turn more. Since it was running ruff I readjsuted the valves with the car running by losening them till they ticked and then tightening them 1/2 turn more. The idle changed slightly but it was still idleing bad. Any possible vacuum leak source, intake gaskets, hoses, brass fittings, throttle body, rubber ducting after the MAF on throtlebody, was sprayed with starting fluid and the idle never shanged. I noticed some arcing with the lights off by the plugs in the head and I am getting new wires and ignition module. The SES light doesnt show any codes unless I reset the timming and I get a code for the EST. The engine shakes badly and when put into gear almost dies. It smooths out some at higher RPM's but sounds sick. When I blip the throttle with the EST disconnected and looking at the mark on the balancer I notice that every once in awhile the timming will retard about 2 degrees and then the engine with backfire through the intake. Most times it will advance and fall back to idle. The timming is rock solid at idle while the engine just shakes and shakes. The engine "feels" tight and wont rev freely eighter. The cam was installed straight up with a new timming chain and the dots perfectly aligned. The lifters and pushrods are new.

ImportsRsloths

Well my engine did the same thing and SHAKED LIKE CRAZY ..... it ended up being the valves being way off and made 3 cylinders have ZERO compression... also the firing order of the wires was messed up.... id definately triple check that!!! THE PROM IS NOT YOUR PROBLEM!!!!!

racereddy20

sounds like timing to me. Just my .02 cents. When you installed the cam was the engine turned so that both dots met in the middle? The fact the engine feels tight also makes it sound like a timing problem.

racereddy20

Oh yeah do you have a compression tester? If so test the compression and make sure that your not more that 20% off on the lowest cylinder compared to the highest cylinder.

Slow89Iroc-Z

Well I never got around to working on the car today since I had to work till 11pm and be there at 5am....... I have a feeling that it wont help though since they were adjusted once already......... I will wait and see

Slow89Iroc-Z

Well guys I am stumped......I installed the new wires and readjusted the valves while the car was running to 1/4 turn past stop ticking.....The damn thing idles the same.....I just dont know????? I am gonna put the stock injectors back in and see if I got a crap set from SVO.......other than that I havent a clue........help???????

SLOW91TA305

hey SlowIroc,

I doubt there is anything I can do to help you out but I have access to a scan tool.

I live in Hickory Hills.

Slow89Iroc-Z

SLOW91TA305, I live in Burbank I would apreciate it if you could put the scan tool on my car for a bit to see whats wrong.....

Slow89Iroc-Z

I put the stock injectors back in and its the same...... See my other post for more info...... I need help guys I am loosing it. Probably gonna order a new cam and lifters and install those since I am lost right now.

Slow89Iroc-Z

please dont give up on me......I need help.......

racereddy20

before you replace the cam and lifters try replacing the distributor pick up coil and ignition module. Both parts shouldnt cost more than 40 bucks and shouldnt take more that and hour to replace. If your fuel pressure is strong but the engine idles and runs like crap it might have something to do with the igntion system. Like i said both parts are less than $40 and they will be alot easier to replace than a cam and lifters.

anesthes

iTrader: (12)

Did You get that scantool reading?

Can you pull each plug (off the cap end) while running and make sure that every cyl is firing? Don't do it on the plug end, or you'll get shocked.

Did you do that compression test?

You absolutely positively lined up the dots on the timing gears right? And your dist is not off by even a tooth?

Everything is plugged back in, including your MAF right?

No vacume leaks at the plenum? Spray some carb cleaner and see if the idle changes.

Without seeing it its hard to diagnose, sounds like the last 20 cars I fixed. Could be an ignition problem, could be a air problem, could be a timing problem.


I just noticed your running a stealth ram.. Does that have EGR? if not, you made sure you disconnected the EGR at the solenoid, right? And plugged the vacume line?


-- Joe

89ProchargedROC

just a FYI....i didn't read through the rest of the posts but did you ever try a different computer? sometimes they can go bad

i have an extra one you can throw in and try

Slow89Iroc-Z

how do I know if my distributor is off a tooth? base timing is at 8 degrees btdc. I already replaced the ignition module and pickup coil. I am waiting for the link to be shipped by AKM... he said there is a delay with the connectors. I did a balance test by pulling one injector at a time and the rpms change the same on each cylinder. There are no vac leaks I sprayed starting fluid all around. I think its the timming cus with the black/tan wire disconnected to set the timming when reved it will ocasionally backfire through the intake. I watch the timing when this happens and it retards a bit and then pop......

mystikkal_69

iTrader: (2)

usually when it backfires through the intake either the timing is way retarded or it's running real lean. it kinda hard to diagnose without looking/playing with it since you covered almost everything.....

jeff1367

iTrader: (1)

I have a very similar problem to you. I had a custom chip burned before my rebuild, and when i had the stock heads and cam, and it ran fine. After everything was put in, it did pretty much the same thing you said: loss of power, RPMs jumping around at idle, and almost dies out when put in gear, so I'm guessing its not the chip. I am as confused as you are about this problem. I live in Oak Lawn, so if I figure it out, I will help you out with it. If anybody has anymore ideas then what was already said, let us know!
Thanks,
Jeff

Scott 88 GTA

The fact that you tried all three of these different .bin's and noticed no change in idle has me wondering if something is forcing the ECM to run in limp home mode. Because you should notice some difference between them. I would suggest trying a stock memcal in your computer (one that hasn't been modified to be able to swap the PROMs) and if that doesn't change, try a whole new computer with the stock memcal too.

It's kind of a shot in the dark, but it's the only thing I can think of that hasn't been mentioned yet.

Slow89Iroc-Z

I finally got my scanning tools together and everything is like 120-133 across the board with only like 3 degrees of retard at WOT no knock elsewhere. Lots of 128 and zero knock retard. I assume its tuned fairly well. Would a bad cam still have these results? The car shakes so much at idle. At the track it ran a 14.3 at 98MPH. In stock trim I ran a 14.0 at 99MPH. WTF is wrong????? Please help.........

91RamAir Formula

did you try reading the plugs? pull them after it has idled for a while and see what they look like. You know the old school way.

Chris Ja

I had the same problem after my build up. Cam,heads,Superram,10.1 trw,TES ect. I used all Lingenfelter parts. As was stated when you go with a big cam you loose vacuum at idle. Mr Lingenfelter told me to set my idle to 1100 RPMs at idle and engine would run fine. I adjusted the set screw on the TB to open the throttle blades up more and engine has a loop and idles at 750 RPMs in gear. Still runs rough on cold starts but other than that run fine. Hope this helps.

Slow89Iroc-Z

Yea the idle is improving with everything I do nut it shakes a lot still. But why such the slow times????

Chris Ja

I do not see were you replaced the converter or changed gears. By replacing the converter and gears you would pick up around .50. With the cam you are using you are not hitting the power ban until about 2600 rpm's. You should go with a 2800 to 3000 rpm stall converter and 373 gears. This would keep you in the power band and also help idle with loose converter. The hot cam will allways have a rough or loopy idle. It will never be like a stock cam.

Slow89Iroc-Z

Problem is that I am not just down a .5 second on power but about 1.5 seconds slower

camarojoe

The actual correct way to adjust the valves is per cylinder, when the exhaust (valve) starts to rise tighten the intake side with your hand until you can't, then with a socket put another 1/2 turn on it. Do the exhaust side when the intake is 2/3's the way down etc. I know from experience that if just one set of valves is off it can make a huge power loss. I think I had one exhaust valve staying open and it cost me like .8 of a sec. If the problem's not your valves I would suggest you have your distributor checked out by someone. I really think your problem has to do with one of these. And I also want to say your PROM is NOT the PROBLEM. My engine (same cam as yours) when idling at 750rpms or above idles perfect with either the stock chip or with my custom chip.

Slow89Iroc-Z

OK....little bit of an update. Had a friend put a vac guage on it and its only pulling about 8 to 9lbs of vacuum at idle. OK thats bad. He also shot each header tude with an infraded heat gun and they were all close in temp to eachother. Here is the whats got me stumped. The car has always smelled rich at idle but he put it on an exhaust gas analysizer and its running pig rich. At idle the Hydrocarbons were almost 3000ppm but the CO2 was alright. Funny thng is that the computer was showing a 133BLM at ldle which isnt that far off and most part throttle was 120-128. On Tuesday we are gonna do a compression and leakdown test. Vac was not steady...moved back and forth about a 1/2 pound or so.....

Ed Maher

Slow, would you mind if i closed this, or merged it with the other thread so as to keep the info in one place? Makes it easier when people need to refer back to things, or follow the troubleshooting. Just post back which you'd prefer

Slow89Iroc-Z

go ahead and merge then together ......there is good info in both threads