New Head...won't start

[RoasT BeeF]

I just got done doing a head swap on my car. Brand new rebuilt head from the machine shop. I got everything back together today and thought I was good to go. This is the 4th time I have done a head swap/timing job on this car and this is the first time it hasnt started. Anyway here is what happend.

Tried to start the car but all it did was crank and not fire. I checked spark and fuel and I am getting both. I flipped the CAS 180 with no results. After I messed with it for about an hour I got pissed and went inside for awhile. Came back out and tried to start it. It fired the first time but didnt run. Second time it fired again but didnt run. This happend like 4-5 times before I decided to press the gas to the floor when I started it. It fired and ran for probably 1.5 seconds and died. Now it just cranks and wont do anything again. I pulled the spark plugs and they are drenched with gas so I am gonna let it sit overnight and dry out and then try it again in the morning.

What am I missing here?

 

[RoasT BeeF]

Found the vac leak.

Inner Throttle Body gasket is shot. It was a little iffy to begin with but the dealer didnt have one is stock so I tried to make mine work with RTV but it didnt hold. I will just have to order one from the dealer and get it installed when it arrives.

Things are looking up! Finally!

 

[GTM]

Originally posted by RoasT BeeF
Found the vac leak.

Inner Throttle Body gasket is shot.
...
I tried to make mine work with RTV but it didnt hold. I will just have to order one from the dealer and get it installed when it arrives.
Things are looking up! Finally!

If it is going to be several days for the gasket why not make one from a brown paper bag? Put a thin film of RTV both sides of the gasket, let stand for 15 min, then assemble. The RTV will skin over yet make a good seal so you can take it apart in a few days.

Cheers,
GTM

 

[BUCK]

My Mitsu guy said he couldn't get just the Gasket between the Throttle Body & Intake - only the one between the Horn & the Throttle Body - I cleaned it up with a little electrical cleaner & used the Hi Temp Cooper colored RTV on both joints - but any RTV should work on that joint IMO - I just went around all those little holes on the Inner side & made a thin RTV gasket & torqued to spec. It's been holding great for months... I wish I had deleted that silly brace from the CAS to the Throttle body bolts though...

 

[RoasT BeeF]

I cut one from gasket paper and used RTV on it and installed it last night. Car still idle's like shit and would not start this morning unless i kept my foot on it until it warmed up. The TB gasket fixed some of the vac problem. I was getting 0 on the guage now im getting 10 but thats still low. I was getting around 18 before. I messed with the idle all day and cant get it to run right. It almost dies when I put the clutch in while comming to a stop. Then idles aroud 500 RPM's. BISS screw is all the way open.

I have also heard that if the exhaust cam gets retard a tooth or so the vac readings will suffer. I checked timing again today and its right on...

 

[BUCK]

Silly question RB - but what's the status of your EGR?

 

[GTM]

Originally posted by RoasT BeeF

...
BISS screw is all the way open.

I have also heard that if the exhaust cam gets retard a tooth or so the vac readings will suffer.
...

Gently run the BISS screw all the way down to the seat then back it off 3 complete turns. When everything is running right it should be usually be within 1/2 turn of that setting unless you have other problems. You have to start somewhere so now you can look for the real cause which may have been masked with the BISS being wide open. I believe after 4 turns out their will be little to no change in the orfice diameter.

RE retard exhaust cam: this is true it is also true you would start to endanger serious piston / valve interference problems especially at high rpm if you get valve float.

And if the intake is too far advanced pistons / valve collision can occur. On more radical Hemi engines with lots of lift valve to valve interference can occur.

Cheers,
GTM

 

[RoasT BeeF]

Trust me I know alllllllllllllllllllllllll about that valve/piston collision thing.

I will run the datalogger on it tonight when I go to my mom's and see whats up with my EGR's. I also thought about picking up some silicon vaccum hose from autozone or someplace and replacing all the vaccum lines. Will try the BISS screw thing as well but I am pretty sure I moved it all around with no real results.

 

[RoasT BeeF]

I realized my EGR is already blocked off. It reads -28.2 all day long on the datalogger.

Car still didnt want to start when I went out there tonight. Had to keep it above 2k until it got warmed up or else it wouldnt even idle. I am starting to go back to how my exhaust cam was hard to turn and just wondering if its possible that the cam is so hard to turn (especially when its cold out) that the engine cant even maintain a steady idle and wont run when its cold.

 

[BUCK]

RB - just for giggles take the Vac line to the Brake booster off at the backside of the Intake & cap it with something - (you won't have Power Brakes of course so be careful if you drive it) - mine's going bad as we speak...

 

[RoasT BeeF]

So you want me to pull that hose off and cap it while the engine is cold like before I start it up in the morning to see if that does anything? Or wait until the engine is warmed up and then cap it? And ya want me to go driving around with it off? Just makin sure.

It seems to idle pretty good once its warmed up and I have been driving it for about 5-10min. Idle's right around 1000 pretty steady. Its just really frustrating how it wont start when its cold. Tonight I went out there and turned it over and it started and I kept my foot on the gas but it died like 3 sesconds later. I tried it again and it would not start. Let it sit for about 5 minutes and it started and I had to keep it above 3k....

 

[GTM]

Originally posted by RoasT BeeF
...

I will run the datalogger on it tonight when I go to my mom's and see whats up
...
Will try the BISS screw thing as well but I am pretty sure I moved it all around with no real results.

Are you able to save, print out your datalogger results so the guys who know can read them?

Read my lips, with the BISS all the way in it's pulling air from somewhere else. Period!! no if and but or nor for's about it.

Throttle plate/shaft is bent, out of adjustment, vacuum hoses, manifold gasket, stuck selonoid valve, wrong connections, throttle switch.

I can't see a tight cam causing this type of problem.

Cheers,
GTM

 

[RoasT BeeF]

BISS is all the way out not in. I will mess with the logger and see if I can find out how to save and print.

 

[GTM]

Originally posted by RoasT BeeF
BISS is all the way out not in. I will mess with the logger and see if I can find out how to save and print.

I thought you said it didn't matter where you set it. Why don't you put it at the 3 turns out and leave it there then do your datalogger tests? Where you have it is just compensating for _WHAT_ the problem really is. If you find someone who tells you no, GTM is full of s..t with that setting put it here go for it. I'm getting worn out with chasing down everything but logical methodical processes.

Cheers,
GTM

 

[RoasT BeeF]

I understand that. Just clarifying that it is all the way out, not in. I have it all the way out because thats they only way the car will idle without dying. I cannot do logging with it at 3 turns out because the car won't even idle.

 

[BUCK]

RB what I was trying to do was isolate a possible leak at the Vacuum Booster for the Brakes - You pull the line at the back of the Manifold (which should be a clamped Vacuum line IMO) & cap it with a plug - or even some duct tape temporarily - & yes you will have very limited brakes while this is done but there is no need to drive it - If it just idled a hell of a lot better you have a Vac leak at the Booster Diaphragm.

 

[RoasT BeeF]

Sorry GTM it just seems like I have tried about every logical methodical process and I feel that we (manily myself but anyone else who is and wants to help) are going to have to dig deeper than just the basics on this one. I understand that you are probably getting just as frustrated with having to answer all these stupid questions as I am with having to come in a post 2-3 times a day on how my car runs like shit. I do appreciate all the help you and Buck have give me thus far. There arent many people who I feel actually really care about other peoples problems and want to help on this site, they just want to look smart. I feel like both Buck and yourself are 2 of those who really want to help and please understand that I appreciate it!

 

[RoasT BeeF]

Originally posted by BUCK
RB what I was trying to do was isolate a possible leak at the Vacuum Booster for the Brakes - You pull the line at the back of the Manifold (which should be a clamped Vacuum line IMO) & cap it with a plug - or even some duct tape temporarily - & yes you will have very limited brakes while this is done but there is no beed to drive it - If it just idled a hell of a lot better you have a Vac leak at the Booster Diaphragm.

Ok I will try that tomorrow. I am also gonna just take my mbc completely off and hook all vac, turbo related lines back up the way they were when I bought the car.

Thanks man

P.S. A long time ago I thought I saw a thing on the vfaq on how to check for vac leaks....now I cant find it. Am I just dreaming or does it really exist? hehe

 

[GTM]

Originally posted by BUCK
RB what I was trying to do was isolate a possible leak at the Vacuum Booster for the Brakes - You pull the line at the back of the Manifold (which should be a clamped Vacuum line IMO) & cap it with a plug -
...

If it were leaking then he should be able to screw the BISS all the way in to it's seat.

He's getting too much fuel, (plugs wet, fuel on top of pistons) something is TELLING the ECU to do this. He found a bad connection on the temp sensor but I don't think he's pulled it and tested in water. To compensate for lack of proper air flow he has a fully open BISS to burn the excess fuel. Yes, no??

Cheers,
GTN

 

[BUCK]

P.S. A long time ago I thought I saw a thing on the vfaq on how to check for vac leaks....now I cant find it. Am I just dreaming or does it really exist? hehe

Easiest way is to "sniff" around with a can of brake cleaner (or choke cleaner - or ether) & the little red nozzle thingy that directs it to a finite spot while idling - if the car stumbles (or it may race up with the Ether) - you found the leak~!

 

[GTM]

Originally posted by RoasT BeeF
Ok I will try that tomorrow. I am also gonna just take my mbc completely off and hook all vac, turbo related lines back up the way they were when I bought the car.

Thanks man
P.S. A long time ago I thought I saw a thing on the vfaq on how to check for vac leaks....now I cant find it. Am I just dreaming or does it really exist? hehe

Go take a look at this and see if it can help.
http://www.vfaq.com/mods/BISS-1G.html

Thanks for the compliments, it's so frustrating not being able to touch the car so you can get a SOP idea of the problem.

Cheers,
GTM

 

[RoasT BeeF]

Yeah I ground those ports everytime I mess with the idle. Blah maybe I will just take it somewhere and have it looked at.

 

[RallyGSX]

Well, if you don't have a vacuum leak (not likely), a couple things I might check would be the ECU and Compression. Change out the ECU if another's available from a friend's car or a spare. Since this isn't likely, as you have a '90, you can remove the cover and check for burns, especially around the caps. Both ECU and Compression are a little unlikely, but you can check both very quickly. If you have not done so, PLEASE build a intake leak tester.

Good Luck and Merry X-Mas,
Dave

P.S. Also, you could get specs to test your various sensors, and make sure they are operating correctly. MAF, Temp, CAS, etc.

 

[GTM]

Originally posted by RoasT BeeF

... Blah maybe I will just take it somewhere and have it looked at.

It may come to that.

I went back and checked for PCV valve mention and found nothing. Could the be plugged for some reason? We know the oil is full of gasoline which will burn off eventually but still make it run rich. If this is stuck closed you will need to open the BISS to gain the additional air which would have come through the crancase.

If it's not a big problem restoring it to original config assuming it will run right and then add each mod 1 by 1.

I didn't know you had made any mods. This is just one of the reasons I don't like to get involved with modded cars for so much can go wrong which don't follow the normal diagnostic process.

Cheers,
GTM

 

[BUCK]

As far as Vac hoses I personally run the PCV & the Valve cover vents - the Fuel Pressure Solenoid hoses - the Brake Booster hose & of course the Turbo control hoses - NOTHING to the Throttle Body - & don't let this thing kick your ass RB!

http://www.taboospeedshop.com/emissions.htm

 

[RoasT BeeF]

Ok I have made some progress...

Last night I replaced all vac lines and PCV valve. Going off the link that Buck left I have the "full race" setup. After I replaced all vac lines and PCV valve I fired it up. It was idling around 3k! I had to turn the BISS waay down...good sign. I messed with the BISS and throttle linkage for about 10 minutes and got it idling around 750RPM. I knew I was making progress but didnt want to call it good until I let it sit overnight and start it in the morning when its really cold. I went out there this morning and tried it and it started first try and idled at about 1000 RPM's for a good 2 mintues and then just died... So I tried to start it again and it took 3 times before it finally did and then it was idling all shitty again around 400RPM's barely staying alive. Once it got warmed up it idled fine tho...and I did notice that my guage is reading about 14 now as compared to the 9 i was getting before. So I made SOME progress but I still dont understand why it took so long to get it started. I am starting to rule the vac leak possibility out now because I would think it should start up and keep running with -14 In Hg. What do you guys think?