88 930..big problems?

porsche2fst · 01-07-2006, 06:27 PM

I have an 88 930 with a 64mm garrett full breadth intercooler and a test pipe. Car started running badly IE at around 90mph when it hit about half boost it would start hesitating with a little backfire. My mech told me to replace the warm up regulator of which I did. Car still has a heck of a time warming up. I have to sit in the cab and keep my foot on the pedal or it dies. The other day while coming home it backfired pretty good and started running rough. Since then I have put a new cap and rotor on it and checked all the plug wires. It is NOW running with a hard miss! Ever since the backfire it has. I noticed the distibutor is advanced all the way to the stop also. There is oil on the inlet seal to the cis and oil accumulating on the line off the intercooler where there is a mechanical boost control. Mechanic says the engine has probably eaten a ring ( hence the oil) and is going to blow up. BUT when he put the garrett on my car he just pinched the oil line a little to it so as to decrease the oil flow to the turbo since the garrett is ball bearing and doesnt need as much as the stock one. Lots of problems guys. Any help? Car doesnt smoke at all except start up...could it actually be blown up? And what is up with the constant miss and distibutor being advanced all the way to the stop?

WydRyd · 01-07-2006, 06:31 PM

I'm no CIS guru, but this sounds like it's leaning out and detonating/pinging under load. The oil in/around the intake could possibly mean bad rings.

Best test is a compression test followed by a leakdown on any suspect cylinders.

Sorry I can't be of any more help. Hopefully the CIS 930 guru's will chime in

mb911 · mb911's Garage

Pinching the oil line would put the wrench in question if you ask me. That kind of seams like a rig more than anything. I would do the following myself

1st compression test (just to verify compression in every cylinder)

2nd verify turbo is still spinning freely (could pinching the line pinch it most of the way off causing lack of lube then eat the bearings then the seal causing the seal to throw oil up into the IC etc?)

Just a good way to rule things out. Now also not familar with the intakes on ther but From memory it looks similar to the 3.2 I would check to make sure noting poped off or broke with the back fire.

I hope there are some 930 guys that can help

porsche2fst · 01-07-2006, 06:42 PM

the wrench is definately in question here. there is still plenty of oil getting to the turbo though, maybe too much still since it drips a little hahah

MobileWrks · 01-07-2006, 07:04 PM

Why would he tell you to replace the WAR... Did he do any test on it... Have you tested to make sure that the dist advance is working??? Check the koax cable to the dist, its supposed to be green, check and see if its burning by the conectoR....

porsche2fst · 01-07-2006, 07:11 PM

He did no test on it. But did say it was going bad a long time ago..replacing the almost 700 dollar part did nothing. As to the green wire off the back of the dist...isnt that a ground? How to check adv?

DzusFast · 07:50 PM

Some good responses here starting with "Best test is a compression test followed by a leakdown on any suspect cylinders".

Sounds like your making calls to your mechanic rather than paying him a visit; nothing wrong with that, but nothing beats a good diag. Your timing should NOT be on the stop; your WuR was probably fine-did he or yourself do a CIS pressure check? it would solve a lot of questions here..., If we were betting on the outcome of what's wrong, my money would be on the fuel pump! that would be my "Guess".

I, on the other hand never guessed with my '88 930. Another poss. is vacuum leak; that would through it all off too. You have a hard miss and THAT cyl. needs to be found first.

Start with compression, if low, leak-down check like the man WydRyd said...IMO

Good luck

porsche2fst · 01-08-2006, 07:13 AM

I am definately making calls to the mech. I moved to the coast of Ms about three months before the storm and as you know...everything down here is gone haha So my old Mech is hearing from me a lot. I will do a leakdown today and post results. By the way..since I replaced the WUR would it throw my mix off?

ewave · 01-08-2006, 09:33 AM

It is possible that there is a leak at the intake manifold to head. Check to see if the intake manifold bolts are tight. They were loose on my turbo, which cause the intakes to leak. The back fire may have blown out the gasket, making the problem worse. This would also cause uneven running, and warm up problems because of the excess air being sucked in when not under boost. On my car, when it had this problem, I could smell gas when under boost because the air/fuel was being forced out of the manifold leak when under pressure.

BTW, I purchased a rebuilt WUR for my 89 turbo, and it was only about $200.

Here's link on my WUR problems.

'89 911 (930) running poorly. (5mpg)

porsche2fst · 01-08-2006, 01:18 PM

Compression is good all the way around..#2 had a leakdown of about 20%. there was a nut missing off the manifold that I replaced and tightened all the manifold nuts ..none were what I would consider loose. As to vacuum I found a screw in the vacuum side off the WUR...yes...a SCREW in the line. When I pulled this out I discovered heavy vacuum on this..pardon my idiocy but WHAT is this vac supposed to be hooked to? I also took a line from this to the distibutor and had no response at all...distibutor advance bad?

DzusFast · 03:01 PM

Replacing anything that controls your fuel pressure such as the WUR 'MAY/WILL' throw off your mix. If it runs exactly the same as it did before you replaced it, concern yourself with the HARD miss you stated about now and make sure to adjust the CO when done (With a 4 gas anylizer of course).

1) What did your plugs look like and did you replace them while they were out? Please tell me you Closely inspected them.

20% leakdown is NOT acceptable (Was it cold?), it's marginal rebuild time for me I'd think but get another opinion ;
2) what do the other cylinders show?????????? The variation between cyl. is my concern.

To check the advance machinism pop the cap off and wiggle the distributer shaft checking side to side play for excessiveness, also twist it to see if the springs are broken....does it return firmly? It's been years since I've worked on an '88 3.3 so pardon me if it doesn't have mechanical like I remember.

For the vacuum advance, you will need a vacuum hand pump from your local tool/Automotive supply and attach to the diaphram on the side of the distributers vacuum port.

BTW- I don't discount the possibility of a bad fuel distributor / Fuel pump with a sticky plunger, I've seen it B4(Ppssssst: Hey, check the pressures)

3) Does it start like normal? or is it hard starting?

porsche2fst · 01-08-2006, 06:22 PM

All other cyl were between 10-14% PLugs all looked good under a mag lens except all were black..definately running rich. Hell of it is...I dont even know where the fuel pumps are located...I need to get a manual on this car pretty bad now. Since there is no mech within 2 hours worth his salt. No idea how to check the pressures on the pump. I do recall that when I installed the WUR one of the fuel supply lines on top started leaking so I tweaked it down.

DzusFast · 01-08-2006, 06:47 PM

Quote:

Originally posted by porsche2fst
All other cyl were between 10-14% PLugs all looked good under a mag lens except all were black..definitely running rich. Hell of it is...I dont even know where the fuel pumps are located...I need to get a manual on this car pretty bad now. Since there is no mech within 2 hours worth his salt. No idea how to check the pressures on the pump. I do recall that when I installed the WUR one of the fuel supply lines on top started leaking so I tweaked it down.

Checking for correct fuel pressure at the right locations and tempuratures requires a high pressure gauge and specialty fittings. ( Your fuel pump is located above a cover panel between the front tires underneath but location isn't necessary since pressures checked @ engine bay.)

Are the plugs shiney black (Oil), or flat black in color (Fuel)? replacing them now doesn't matter since we know that you have a rich-run condition. Soooo no mechanic for 2 hours, no factory manual, and no high-press gauge (Around 1\5 the price of a WUR)

Sorry I can't be of more assistance @ this time.

porsche2fst · 01-09-2006, 03:47 AM

Kinda screwed huh..I will persevere though. Send it out to rebuild and efi if I must. NO WAY I am going back to an american hotrod after getting to 160 plus in this thing and still feeling solid!

DzusFast · 01-09-2006, 02:04 PM

Quote:

Originally posted by porsche2fst
Kinda screwed huh..I will persevere though. Send it out to rebuild and efi if I must. NO WAY I am going back to an american hotrod after getting to 160 plus in this thing and still feeling solid!

Nobody never said you can't have both! unless your married of course...

porsche2fst · 01-09-2006, 03:06 PM

Nah...got rid of her. Kept the kid and car...hahah life is grand