jimmy198920

I have a 88 firebird 2.8l not running right. It won't rev past 4k has no power idles rough but it all ways did. I changed the lower intake bc the bolt holes to the therstmat broke when I tryed to change it. I cleaned the top part of the motor when I changed the intake an to change the gasket I had to take the push rods off. I'm thinking I don't have them adjusted right or my timing is off. Any one got any ideas???

Base91

iTrader: (1)

Are you saying you cleaned what you could get with out taking the heads off? I had a similar 'rev limit' issue after bad maintenance by PO and running rich for years. I put Seafoam in the gas and it started to run better and better and will now rev past 5500 and feels like it has more but I don't want to push it. As for rough idle, check for vac leaks, Idle valve, plugs wires etc. etc. then maybe O2 sensor. And of course be sure you put everything back right.

jimmy198920

Ill try the seafoam when I go to town. I just cleaned under the intake. I've all ways had idleing problems with my car. I'm not that worred about if I can fix that prob or not. I'm wanting to get it running to where I can drive it to work. When I get a job I'm going to rebuild the motor an I'm not sure what kind of parts I'm going to put in it. Ill prob post when I get ready to rebuild on ideas of what to get. I hope the seafoam works ill find out in about 3 hours.

Base91

iTrader: (1)

If you put the Seafoam in the gas it's a slow improvement as you drive the car. You can also pour some directly into the carb or plenum and let it sit for a while and when you start the car it blows a bunch of the junk out. There should be instructions on the can I think.

jimmy198920

Ok ill try it. If it don't work I'm going to take the valve cover off and check the valves. I've got 2 vechiels I'm working on the other is a 93 s10. I hope the seafoam works so I don't have to take the top and middle part of my intake off.

Project 3.4 Camaro

What did you set valve lash at? Cause the 1/2 turn past 0 lash doesn't cut it in my case,(after 3.4 swap my rockers were loose as hell after doing lash by haynes specs...) also could be you have flat lifters or a dead cam, whats your oil pressure like?

jimmy198920

Ever scene I got my car the oil presser didn't work right tell I changed the lower intake. The presser is around 40 psi and the lowest its been was 20 psi. Be for the intake change it would go from 0 to 40, 60 psi. I changed the sending unit an still went up an down. I think the gage is messed up or something. As for my valves I went about 3/4 past 0 lash where I could not move the rods. I'm sure my cam and lifters are in good shape bc I checked them while I had the intake off. For 250,000 miles on the car, the cam, lifters, rods, rocker arms look in good shape. I'm thinking I'm going to have to take the covers off start the motor and set the valves while its running but I'm not sure if I can do it with this motor. I have a Clinton manuel for my car an it say 3/4 past 0 lash for the valves

Base91

iTrader: (1)

Does the engine have 250,000 miles on it? Has it been rebuilt? If not it may be time for a lot more than adjusting the valves.

Project 3.4 Camaro

^If it hasn't had a rebuild I would do a full rebuild or find a lower mile engine to swap in
Possible you have crappy compression, that would cause both rough idle and low power. Also double check your valves haven't come loose, haynes says either 3/4 or 1/2 turn, I can't recall, but after running my car for 2 weeks and having to replace the fuel pump, I discovered it was idling rough and making some bad noises, every single rocker arm was loose, granted in my case my valvetrain will probably need more time than normal to break into a good groove, so probably didn't help, but still, wasn't tight enough for sure, and 1.5 which 60/6 says to do seems a little tight, I will probably wind up going 1-1.5.
But honestly, if it hasn't been rebuilt I wouldn't even mess with it, full rebuild or replacement imo. Cause if you just try to fix one thing at a time you will probably constantly have problems on a motor that high mileage if its not been rebuilt.

jimmy198920

Yea it is 250,000 mi on it. The motor ran great before I changed the intake. Before I had to changed the intake I took it on a 2 1/2 hour drive ran great there and back. I'm going to rebuild the motor after I can get a good job and get my s10 running then I'm selling it to get me an older chevy or gmc truck with a v8 in it. Then I'm rebuilding the motor the orgional tranny and rear end bc I still have them when I had to change them. I'm wanting to get it running like it should. I tryed what the clinton book spec and didn't work.
When I start it up it sounds good when I hold it at about 1200 rpm I can rev it up to 4k slowly and sounds good. I'm going to try the 1.5 turns on the valves and try that. I get every thing I need to work on my car. I need to buy things to get my s10 going an I don't have the money. I lost my job from the 5/22/11 tornado in joplin missouri I'm going to go work on my car now

Base91

iTrader: (1)

As a general rule with cars (and everything) if you do something and things get worse at least undo what you did and start again. If the engine ran fine before make double sure everything is back the way it was. And good luck with the cars and a job.

Maverick H1L

iTrader: (8)

DO NOT turn the rocker nuts 1 and a half turns after no lash. You will have NO compression and go NOWHERE. Between 1/2 and 3/4 turn is all you need. Double check the torque on the lower intake bolts as you go, and make sure none of the injector o-rings (and the o-ring on the cold start injector tube) have not been cut and are creating a vacuum leak. Also check the nipples on the ends of the idle air pipe that runs from the lower intake to the throttle body and also the PCV valve connections for cracking and disintegration.

jimmy198920

Thanks for ur help. It is my valves not set right. I'm going to get a compression tester and set the valves that way. I'm going to hold off on that and get my s10 going I just got to put it back togther and find a short for the fuel pump on it. If setting the valves with the compresson tester don't work I'm just going to rebuild it. Before I do that I'm going to get some ideas on what parts I should get and if I would be able to put a twin turbo on it. Ill be replacing everything inside the motor with performance part. Ill repost when I'm ready to rebuild it but if u got ideas on what brands to get u can post them hear or when I re post. When I go to reset the valves to the 150 lbs witch is what it had 7 months ago when I did a compresson test and I'm going to go over all the parts. And valcum lines. I'm going to check the torke on the intake bolts. The 7th or the 8th I'm renting the tester after I get what I need for my s10. Again thanks for the info

Maverick H1L

iTrader: (8)

Don't need a compression tester. No more than 3/4 turn and the valves will work fine. 5/8 turn is best, but harder to get to with a ratchet.

jimmy198920

Ok ill go 3/4 turn. To get 0 lash is roll the rod untell it stops then tighten 3/4 of a turn or is it untell the rocker arms don't wiggle. The second one is how I set my valves. I've heard different ways of getting 0 lash and not sure witch way is the right way.

Maverick H1L

iTrader: (8)

No, you don't spin the rod... You wipe it clean and then check for VERTICAL play, between the rocker, rod, and lifter seat. When the rod stops moving vertically, that's zero lash, and tighten the nut about 3/4 turn. I prefer a "breaker bar" for doing my valves as it's direct and easier to tell when the point of zero lash is.

Oh, and you can get away with slitting the "DO NOT CUT" parts of the intake manifold gaskets the next time you have to change them. Just one cut in the same place on all 3 sections, slide the cut part behind the pushrods, and slide the gaskets down and into place.

jimmy198920

I thought that was the way to get 0 lash. I wanted to makes sure. When I took the driver side valve cover off 3 of the rocker arms were lose. I'm going to see if any passanger side are lose.

Maverick H1L

iTrader: (8)

Some say spin the rod, I prefer vertical play just to make sure. Just make sure you clean the pushrods up nice or you won't get it right because your fingers will be sliding around on the rods and it's harder to tell when it's right that way.

jimmy198920

Ill have to wait tell 2morrw to work on it. I had a water leak in my house I have to fix. Ill get started on it 2morrow morning

jimmy198920

I've done a compression about 7 months ago all 6 had 140lbs to 150lbs. That's when it had 230,000 mi on it.

Up date on what I got now...befor I set the valves 12,4,6 had 30l,0,20. After I set the valves, Cyl. 2,4,6 has 155,160,165 with the valves set right (3/4 turn past 0 lash). I'm out of time today to work on the other side but I did a compressiom test on 1,3,5 has 0,0,0. 2morrow I'm setting them valves bc I've probably got them 2 tight.

jimmy198920

12,4,6 had 30l,0,20. ... Is 2,4,6 had 30,0,20. I hate the small keys on my phone lol.

Sorry it took so long to reply back. I got a job been working over 30 mi from where I live an then I got fired yesterday so now I have time to get my car going bc my s10 probably needs new rings or valves not really sure yet.

Be for I take the other cover off I need to get a couple of studs for the passanger side. Ill know by 5 2morrow if the valves were the reason for no power.

jimmy198920

I got the valves set right on cyl 1,3,5 the compression is 155,165,160 Cyl. 2,4,6 has 155,160,165. These were dry test. I'm taking a break then put the middle part of intake on the fuel rail top intake and put every thing back together and then I'm ready to put gas in it and start it and hope for the best.

jimmy198920

Up date on my bird got it started and it sounds good. I got to set the timing on it to tune it a little but it runs like it used to. Thanks for all ur help