Chasing my tail with starting issue 88 3.2

[FA-18C]

2 months in, enjoying getting my hands dirty. Car has 1000 miles on it since revival from a 13 year storage, working on the baseline. Overall, car runs pretty well. Pulls through the gears.

When I first got the car, it had a LOT of work done as part of revival, brakes, shocks, every oil line, major servicing etc... Since then I have done the fuel lines, new injectors, cap & rotor. One the past month, starts have become harder - cranking as if starved for fuel, and then once starting, kind of stumbles through increasing RPM. Rough for 15 sec or so, and it appears as fuel flow improves, evens out and goes though the routine RPM at 12-1300 and then settle to 880rpm. I put a fuel gauge on and when the fuel pump kicks on I get decent fuel pressure - but it bleeds right off. The fitting in my kit sucked and leaked, so am working to get a new fitting, or hose and clamps this week.

Hoping to tap into the collective here on my mindset and reasonableness of thinking on this, and the potential parts that will get thrown at it:

Given that the fuel pump, fuel filter and sensors were all new and have less than 1200 miles on them, I am assuming (and will check with meter) those are OK. DME Relay was brand new, changed for a 2nd new one with no change, and also the solid state version - all the same (except get Prime with new DME relay). This afternoon I pulled the plugs - all were LOOSE. I mean just barely threaded in, several not fully seated. The were very sooty, which is likely from them being so loose, but could be running way rich as well.

Slow & sluggish start - I suspect the fuel pump check valve, coil or DME, could this be degraded plug wires? They appear to be original. Car runs really decent, just sucks at starting.

As the car was idle for so long, even though a lot of new parts have gone on, the alternator and coil are still untouched since running. I plan to check the coil, but perhaps the DME and/or coil are impacting the start. the alternator is noisier than I recall, but not horrible. Suspect a replacement is in the future as well.

Random stall at idle - car has been solid until two days ago, and then started randomly stalling at idle during stop and go traffic. Start right up, and 50/50 on whether I need to toe in a little higher RPM. Drives fine. Seems that it idles fine, and you feel and see a burp that drops RPM to 500ish, and it either recovers, or dies.
- Could this be somehow related to the fuel pump check valve issue, or the fuel tank strainer being clogged up and straining the fuel pump?

Plan A is to change out the fuel pump check valve, feed hose, and also the fuel tank strainer. I suspect that between a 34 year old strainer that sat for 13 years and a failing check valve that on start up the fuel pump struggles with some restrictions.

IF (and even if it does) it doesn't address some of the issues, next will go through checking the AFM (connections, OHMs), pull ICV and clean (again) and check resistance and function under 12V. Will also check the sensors, as well as continue search for vacuum leaks. (Note - RPM drops when I take the oil cap off, and visually have checked the spaghetti mess, but will spend a couple of hours again)

Plan B - if necessary, will add in from the buffet line:
- open AFM and see if there are noticeable issues there, try to remap the contact to see if that makes a difference
- find someplace to check exhaust fuel & air ratios to see how out of whack I am
- check coil
- check alternator

Plan C - ala carte parts shotgun, shred $$$ method
- replace ICV
- replace FPR
- replace Coil
- replace alternator
- send DME for service/repair
- send AFM for service/repair

I just want the car to start better...

[brighton911]

Chris, I think you are on the right track to check the screen in the tank and replace the check valve. Then see where you are & hopefully it will be starting up just fine. Question, does your fuel pump run momentarily when you key on ?

[FA-18C]

It does, but only because of the F9 relay. My gut tells me that the fuel is only part, and at 34 years the original coil is just tired.

[proporsche]

If you are losing your fuel ..?..start with fuel pump check valve

Ivan

[FA-18C]

Ivan, you are correct. Installed yesterday and also replaced the fuel tank strainer which had 34 years of crap accumulated. Now starts right up when she turns over. Now need to check for vacuum leaks etc…idle is on the low side and looking at plugs, running rich right now.

[76FJ55]

have you checked the condition of the fuel pressure regulator and damper? pull the vacuum lines for these and check to see if there is any fuel in them. the diaphragms tend to crack with age especially on a car that has been static for an extended period. if the diaphragm leaks it will let raw unmetered fuel into the intake through the vacuum lines. if you have a hand operated vacuum pump you can also attach it to the regulator and damper and pull a vacuum to verify that they hold.

[proporsche]

you can adjust your idle and the fuel mix yourself..

[Matt at Pelican Parts]

If it starts and immediately stumbles at idle, the ICV might just need a good cleaning. Soak the valve end in any sort of degreaser/cleaner like purple power or simple green and to get the gunk out and after a bit you should be able to see the valve/flap inside moving freely.

As others have stated it might be good to look into the vacuum system, especially on diaphragms that help with fueling like the regulator

-Matt

[FA-18C]

Thanks all - I removed and cleaned the ICV and will reinstall. So happy that the starting is better, progress helps with motivation. I have a backup FPR and may install that this afternoon - given the car's history, I suspect that the diaphragm may be toast. Also ordering 4mm vacuum hose and fittings to replace - low cost, and 34 years...Part of me believes that I have slowly addressed some of the old issues, and the sorted some leaks that may have required an overly rich setting to run OK. Now that those are resolved, the idle setting needs to be adjusted.

Of course in this process, found a torn CV boot, so am trying to figure out all of the parts for the 88 to get those inbound. Determined to do all of the work myself on this car no matter the pain and challenges (or until my bank is empty...).

I am trying to get my hands on a fuel air mixture tool and educate myself on how to properly make these adjustments with Bentley and the forum. Just trying to get in the ballpark to start with and then work on fine tuning.

[911obgyn]

I picked up an innovate afr guage and sender, wired it up with power leads and installed the wide band O2 sensor in place of the stock O2 sensor.
I made sure no vacuum leaks and adjusted mixture, idle. It took about an hour of tweaking both to get a steady idle and mixture. Used the method in the bentley manual above. Be sure to check idle switch operation. I also had to replace O ring at throttle body and intake gaskets and the bellow between the intake manifolds.

[Tea Tray]

Check the “fun to get at” vac hoses behind the heater blower:
My ‘87 had a lot of paint residue/brake fluid from the brake booster stuck inside the vac valve on the trombone shaped mess with about 11 hose clamps.
The brake booster vacuum hose that ran down by the torsion tube was cracked in several places.
The whole vacuum system on my car was cracked in places.
Check the idle switch for continuity and consider replacing the flywheel sensors and CHT sensor if original.
My ‘87 sat for a long time in a non-AC place in FL. Heat baking, I suppose.

[FA-18C]

Tea - on the positive side, since last June July the car has all new sensors, valves set, full service, new cap, rotor and plugs, fuel pump. I replaced all fuel hoses and fuel injectors, Clewett wires. New fuel pump check valve and fuel tank strainer. Also new DME (German stock, not URO).

The GOOD NEWS is that the hard start is sorted. After sitting all night in 30 degree weather in the garage, I came home from work and car started first turn of key, 1st or 2nd starter crank. RPM jumps up to 11-1200 for a couple of potatoes, and then hunts between 8-900 and 1200 for 15-20 seconds. If I goose the throttle a bit, settles down to 1K, then around 850-900. So making progress.

I pulled and cleaned the ICV for the 2nd time - that may have helped. I also set the AFM on a new trace path, which seems to really smooth RPM driving. Ran the car this afternoon for 40 min on HWY and in traffic, and never stalled, maybe twice dropped to 700rpmish for a couple of seconds before settling back into 850-900.

Question for gurus - as it seems to be functioning reasonably well now, I plan to hold off on new FPR. Thoughts there? In the next two weeks I plan to pull the airbox to change out the vacuum fittings on the damper to FPR, and will also pull the fan and housing, and valve covers. Will set the valves (1st time in 15 years for me...), clean up and cerakote the valve covers, fan and housing, and also given the noise in the alternator - will replace that (bearings must be in the back end of their life). Will also change out the oil return tubes since I did not get to those. Should I go ahead and swap out the FPR as well? Lots of moving parts and I hate to tune the radio by turning all of the knobs at once...

This car just clicked over its first 1K after storage for 13 years. So I am making progress on baselining this beast.

[FA-18C]

OBGYN -

I have been reading up on the wide band, and that is on my bucket list. Have some competing items on my near term now that we seem to be better (but not fully dialed). First need to do oil return tubes, set the valves, replace alternator, and tackle on CV axle replacement. This may be a Christmas item along with rebuilding my swing arms and rear bushings, then replacing one front control arm and bushings. I am having a blast learning about each of these systems and areas and you all are a built in library of knowledge.

[911obgyn]

I would have the alternator rebuilt at a local shop. Front end bushings, only one side? Do both sides and go with elephant bushings. Glad you got it drivable!

[GH85Carrera]

Originally Posted by FA-18C

It does, but only because of the F9 relay. My gut tells me that the fuel is only part, and at 34 years the original coil is just tired.

Many times, the original old black German coil is THE best coil you can find. Keep the old one safe if you decide to replace it. Finding a quality coil with the proper voltage range is almost impossible.

[FA-18C]

Obgyn, I have a rebuilt alternator on the shelf and will have the removed one rebuilt as a spare. PO replaced one control arm and all shocks. I lan to do other side, turbo tie rods and sway bar bushings and front is all new.

[dtxscott]

The idle hunting when cold is an indication of a rich mixture.

As 911obgyn noted, the Innovate w/wideband O2 sensor is the ticket to get your mixture dialed in.

[Hnichols]

Originally Posted by FA-18C

Of course in this process, found a torn CV boot, so am trying to figure out all of the parts for the 88 to get those inbound. Determined to do all of the work myself on this car no matter the pain and challenges (or until my bank is empty...).
.

If it's the inboard boot (attached to the transmission), it's an easy fix. A new boot (with grease and clamps) is like $12 on this site. Don't let anyone tell you you need to replace the axle.

[FA-18C]

H - as the car sat for 13 years in storage, and the other side was replaced last SEPT by the PO, my mindset is to replace - then I have a known baseline. I will absolutely inspect the one I remove, and will buy the rebuild kit and have a good spare on the shelf. Car has 117K on it, so it is not stupid mileage.

[FA-18C]

So start idle is much improved after FPR and another round of cleaning the ICV. I replaced the FPR vaccum boot, and when doing so, there was a slight dribble of fuel coming out of that vent. I think the diaphragm should prevent that, so suspect that along with the check valve, my FPR may be part of the cranking on start I was having issues with, plus is likely pissing some fuel into the intake adding to the rich fuel and some smoking at start. Clears quickly. So FPR is getting changed out FRI or SAT. Does this diagnosis make sense? Car is running well right now, but I have the FPR in hands, so....